{"paper_id":"3b32b70e-740e-43e3-a488-9d9aebf637d7","body_text":"Reducing dietary cation–anion difference seldom affects rumen fermentation, cellulolytic bacteria populations, and microbiota in goats | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Reducing dietary cation–anion difference seldom affects rumen fermentation, cellulolytic bacteria populations, and microbiota in goats Kang Yang, Xingzhou Tian, Shiyan Jian, Lun Sun, E Han, Fei Wang, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-41136/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background: Dietary cation–anion difference (DCAD) has been receiving increased attention in recent years; however, information on the rumen fermentation, cellulolytic bacteria populations, and microbiota of goats fed a low-DCAD diet is less. This study aimed to evaluate the feasibility of feeding a low-DCAD diet for goats with emphasis on rumen fermentation parameters, cellulolytic bacteria populations and microbiota. Growth performance, urine pH, and plasma metabolites were also analyzed as well. Materials and method: Eighteen goats were randomly allocated to 3 treatments with six replicates of each treatment and 1 goat per replicate. Animals were fed diets with varying DCAD levels at +338 (High DCAD; HD), +152 (Control; CON), and −181 (Low DCAD; LD). This study includes 15-d experimental period and 30-d adaption period. Results: The DCAD level did not affect the rumen fermentation parameters including pH, buffering capability, acetic acid , propionic acid , butyric acid, total volatile fatty acids, and ratio of acetic acid / propionic acid ( P > 0.05). The 4 main ruminal cellulolytic bacteria populations including Fibrobacter succinogenes , Ruminococcus flavefaciens , Butyrivibrio fibrisolvens and Ruminococcus albus did not differ from DCAD treatments ( P > 0.05). The DCAD levels did not affect bacterial richness and diversity indicated by the indices Chao, Ace and Simpson and Shannon, respectively ( P > 0.05). Both weighted UniFrac and unweighted UniFrac showed no difference in the composition of rumen microbiota for CON, HD and LD ( P > 0.05). At the phylum level, Bacteroidetes was the predominant phylum followed by Firmicutes, Synergistetes, Proteobacteria, Spirochaetae, and Tenericutes , and they showed no difference ( P > 0.05) in relative abundances except for Firmicutes , which was higher in HD and LD compared to CON ( P < 0.05). At the genus level, relative abundance of 11 genera were not affected by DCAD treatments ( P > 0.05). Level of DCAD had no effect ( P > 0.05) on growth performance including dry matter intake, average net gain, average daily gain, and feed conversion ratio; and nutrients digestibility of crude protein, neutral detergent fiber, acid detergent fiber, and organic matter ( P > 0.05). Urine pH in LD was lower than HD and CON ( P < 0.05). LD resulted in higher plasma calcium than HD and CON ( P < 0.05) but not for other plasma metabolites ( P > 0.05). Conclusion: We conclude that, with regard to the great importance of rumen fermentation, these results suggest that reducing DCAD is unharmful for rumen status and provide the feasibility of feeding a low-DCAD to goats. Biotechnology and Bioengineering Dietary cation–anion difference Rumen status Ruminal cellulolytic bacteria Rumen microorganisms community Plasma calcium Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Background Dietary cation–anion difference (DCAD; mmol/kg dry matter [DM]) refers to the difference between the number of millimoles of major cations (Na + and K + ) and major anions (Cl − and S 2− ) of per kg of DM in the diet [ 1 ]. Variations in DCAD enables maintenance of electrolyte balance and osmotic pressure, improving the health status of animals. The initial benefit of feeding a low-DCAD diet was reported by Block [ 2 ], who observed that treatment with − 172.3 (mmol/kg DM) DCAD could prevent hypocalcemia compared to a control DCAD of + 448.6 (mmol/kg DM). The DCAD level has been an important parameter in the process of formulating diets in recent years [ 3 – 7 ]. Studies have shown that diets with a lower DCAD could enhance the health and extend the economic life of transition mammary animals [ 8 – 10 ]. Recently, attention was given to the interaction of DCAD with calcium (Ca) concentration[ 11 ], cholecalciferol/calcidiol[ 12 ], 5-hydroxy-l-tryptophan [ 13 ], vitamin D [ 14 – 16 ], and duration [ 17 , 18 ] of blood Ca level increases. Results of these studies indicated that lower DCAD in association with the above factors was effective in improving homeostasis of peripheral blood Ca. Most recently, Santos et al. [ 19 ] and Lean et al. [ 20 ] used meta-analyses to determine the effects of varying DCAD on the performance, production, and health of cows. Ruminant diets usually include up to 70% roughage and so are fiber-rich. As the most important digestive organ, the rumen is the main site for digestion and utilization of nutrient, especially for degradation of cellulose by cellulolytic bacteria. Among rumen measurements, pH is the key parameter determining rumen fermentation status and is often lowered when ruminants are fed high levels of concentrate, resulting in ruminal acidosis [ 21 – 23 ]. Bacteria account for 95% of the total amount of rumen microorganisms [ 24 ], and thus are the main factor to modulate digestive and metabolic activity of the rumen[ 25 ]. Butyrivibrio fibrisolvens , Fibrobacter succinogenes , Ruminococcus flavefaciens , and Ruminococcus albus are reported the four most important cellulolytic bacteria for digestion and utilization of fiber in the rumen [ 26 – 29 ]. However, to our knowledge, there is less information on the rumen fermentation, cellulolytic bacteria populations and microbiota for goats fed a low-DCAD diet, therefore, the present study was conducted to evaluate the effect of a low-DCAD on the above-mentioned parameters of rumen pH, buffering capability, volatile fatty acids of acid, propionic acid, butyric acid, total volatile fatty acids, and acetic acid/propionic acid profiles; ruminal cellulolytic bacteria populations of Fibrobacter succinogenes , Ruminococcus flavefaciens , Butyrivibrio fibrisolvens and Ruminococcus albus , and microbiota. Growth performance, acid-base balance, plasma calcium level and metabolites were also measured. The results should provide a comprehensive evaluation of the feasibility of feeding a low-DCAD diet to goats. Materials And Methods Experimental design and animal management The animal treatment procedures were approved by the local animal care and use committee. Using a randomized block design, 18 Qianbei miscellaneous goats (a native goat breed in the southwest of China; 30.07 kg initial weight and aged 13 months) were allotted to 3 treatments of six replicates of 1 goat per replicate. Animals were fed one of three diets with different DCAD levels (mmol/kg DM): +350 (HD), +100 (CON), and −150 (LD). Diets consisted of peanut straw ( Arachis hypogaea ), faba bean straw ( Vicia faba ) and concentrate which were mixed with NaHCO 3 (HD) or NH 4 Cl (LD) and were pelleted (4 mm diameter), with a concentrate: roughage ratio of 30:70. Goats were fed in separate metabolic cages. The experiment duration was 45 d including a 30-d adaption period and 15-d trial period. The adaption period was divided into three stages. In the first stage (1–12 d), goats were observed for health condition and treated for parasites and disinfected. During the second stage (13–18 d), goats were allowed to adjust to their respective diets. In the third stage (19–30 d), steady DM intake (DMI) was determined for individual goats. After that, in the trial period (31–45 d), goats were fed the treatment diets strictly according to the established DMI at 09:00 and 18:00. All goats had free access to water during the whole experiment. Ingredients and nutrient levels of diets for goats are shown in Table 1. The actual DCAD levels were measured as +338, +152, and −181, showing slight differences from the designed values of +350, +100, and −150 for HD, CON, and LD, respectively. Table 1 Ingredients and nutrient compositions of diet for goat Items DCAD HD CON LD Ingredients Concentrate (%) 1 30 30 30 Peanut straw (%) 50 50 50 Faba bean straw (%) 20 20 20 NaHCO 3 (g/d) 12 -- -- NH 4 Cl (g/d) -- -- 15 Nutrient levels 2 DM (%) 93.70 93.77 93.90 CP (% DM) 13.40 13.64 14.21 NDF (% DM) 39.40 39.64 39.82 ADF (% DM) 30.35 30.62 30.64 OM (% DM) 88.02 87.03 87.71 Ca (% DM) 0.67 0.64 0.68 P (% DM) 0.48 0.49 0.49 Na (% DM) 0.52 0.19 0.14 K (% DM) 1.08 0.98 0.87 Cl (% DM) 0.23 0.27 1.25 S (% DM) 0.16 0.17 0.18 DCAD (mmol/kg DM) +338 +152 -181 1 Composition and proportion (%): corn 51.07, soybean meal 24.82, wheat bran 11.19, rapeseed meal 8.07, CaHPO 4 0.45, lysine 0.27, methionine 0.29, NaCl 0.77, and premix 3.06. 2 Actually measured values. Samples and m easurements Nutrient levels and growth performance Diet samples were collected daily during 19–45 d and stored at −20°C. At the end of the feeding experiment, dietary samples were composited and dried at 65°C and were ground to pass a 1-mm screen for proximate chemical composition determination of DM, crude protein (CP), organic matter (OM), Ca and P [30]; and neutral detergent fiber (NDF) and acid detergent fiber (ADF) [31]. An atomic absorption spectrophotometer (iCE 3000 SERIES, Thermo Fisher Scientific, USA) was used to measure Na and K contents. Silver nitrate titration was used to determine Cl concentration. The S level was determined using the magnesium nitrate method as described by Wang and Beede [32]. The DCAD was calculated using the following equation: DCAD = Na (%)/0.0023 + K (%)/0.0039 − Cl (%)/0.00355 − S (%)/0.0016 All goats were weighed on d 32 as the initial weight and on 46 d as the final weight. The DMI was recorded daily for each goat calculated by allowance of refusals. The average net gain (ANG) was determined by subtraction of initial weight from final weight. The average daily gain (ADG) was determined by dividing ANG with the trial period (15 d). The feed conversion ratio (FCR) was the ratio of DMI to ADG. Total feces was collected during the last five consecutive days for nutrients digestibility analysis. Feces samples from individual goats were dried in an oven at 65°C for 48 h and ground to pass a 1-mm screen for approximate nutrient measurements: CP and OM [30] and NDF and ADF [31]. Rumen status At 9:00, 13:00, and 17:00 on d 44, rumen fluid was collected through the esophageal cannula via a vacuum pump (VP30, Labtech Instrument Co. Ltd, Beijing, China) and was measured pH using a pH meter (PHS-3C, Youke Instrument Co. Ltd, Shanghai, China). Sample collected at 17:00 was used to assess rumen buffering capability (BC) as described by Tucker et al. [33], and the operational procedure was titrating a 10-mL aliquot of the sample from the original pH dropping to pH 5 using 1 N HCl. Rumen fluid (20 mL) was used to detect volatile fatty acids (VFA), and the remaining sample was used for microbial high-throughput sequencing analysis. To determine the VFA, acidified samples were centrifuged at 4°C for 10 min (Thermo Fisher-ST 16R), and the supernatant fraction filtered through a 0.45-µm filter. The 1280 μL of filtrate was mixed with 600 μL of 20% metaphosphoric acid and 120 μL of crotonic acid (internal standard). The VFA concentrations in filtered samples were determined by gas chromatography (GC-2010-plus, Shimadzu, Japan) equipped with a flame ionization detector and a capillary column (SH-Rtx-Wax, Shimadzu), and nitrogen was used as the carrier gas. Rumen microbial high-throughput sequencing analysis was performed by TinyGen Bio-Tech (Shanghai) Co. Ltd. PCR amplification of 16S rRNA genes and Miseq sequencing Ruminal fluid samples were stored at −80°C and the DNA extracted from 200-mg samples using a QIAamp DNA Stool Mini Kit (Qiagen, Hilden, Germany) following the manufacturer’s instructions. The DNA concentration and purity were checked by running samples on 1.0% agarose gels. The PCR amplification of 16S rRNA genes was performed using general bacterial primers: 515F 5ʹ-GTGCCAGCMGCCGCGGTAA-3ʹ and 926R 5ʹ-CCGTCAATTCMTTTGAGTTT-3ʹ. The primers also contained the Illumina 5ʹ-overhang adapter sequences for two-step amplicon library building, following the manufacturer’s instructions for the overhang sequences. The initial PCR reactions were carried out in 25-µL reaction volumes with 1–2 µL of DNA template, 250 mM dNTPs, 0.25 mM of each primer, 1× reaction buffer, and 0.5 U of Phusion DNA Polymerase (New England Biolabs, USA). The PCR conditions consisted of initial denaturation at 94°C for 2 min, followed by 25 cycles of denaturation at 94°C for 30 s, annealing at 56°C for 30 s, and extension at 72°C for 30 s, with a final extension of 72°C for 5 min. The second step of PCR with dual eight-base barcodes was used for multiplexing. Eight-cycle PCR reactions were used to incorporate two unique barcodes to either end of the 16S amplicons. Cycling conditions consisted of one cycle of 94°C for 3 min, followed by eight cycles of 94°C for 30 s, 56°C for 30 s, and 72°C for 30 s, and a final extension of 72°C for 5 min. Prior to library pooling, the barcoded PCR products were purified using a DNA gel extraction kit (Axygen, China) and quantified using FTC-3000 TM real-time PCR. The libraries were sequenced by 2 × 300 bp paired-end sequencing on the MiSeq platform using MiSeq v3 Reagent Kit (Illumina) at Tiny Gene Bio-Tech (Shanghai) Co. Ltd. Bioinformatic analysis The raw fastq files were demultiplexed based on the barcode. The PE reads for all samples were run through Trimmomatic (version 0.35) to remove low-quality base pairs using parameters SLIDINGWINDOW: 50:20 and MINLEN: 50. Trimmed reads were then further merged using the FLASH program (version 1.2.11) with default parameters. The low-quality contigs were removed based on screen.seqs command using the following filtering parameters, maxambig = 0, minlength = 200, maxlength = 580, and maxhomop = 8. The 16S sequences were analyzed using a combination of software mothur (version 1.33.3), UPARSE (usearch version v8.1.1756, http://drive5.com/uparse/), and R (version 3.2.3). The demultiplexed reads were clustered at 97% sequence identity into operational taxonomic units (OTUs) using the UPARSE pipeline ( http://drive5.com/usearch/manual/uparse cmds.html ). The OTU representative sequences were used for taxonomic assignment against the Silva 128 database with a confidence score ≥0.6 by the classify.seqs command in mothur. The OTU taxonomies (from phylum to species) were determined based on NCBI. The four members of the rumen cellulolytic bacteria community ( B. fibrisolvens , F. succinogenes , R. flavefaciens , and R. albus , % of total bacterial 16S rDNA) were selected from “Species” for statistical analysis. Urine pH For precise observation of the effect of DCAD level on acid–base balance in vivo , urine pH was measured once every 3 d during the first and second adaption periods (1–12 and 13–18 d), once every 2 days during the third stage (19–30 d), and daily for the trial period (31–45 d). Urine was immediately dipped with special indicator paper (5.4–7.0, SSSreagent Co. Ltd, Shanghai, China; 6.4–9.0, Fuyang Special Paper Co. Ltd, Hangzhou, China) when goats urinated. Plasma metabolites Blood samples (10-mL) of every goat were collected from the jugular vein into heparinized plastic syringes at 45 d. Samples were centrifuged at 805×g for 15 min to harvest plasma. Plasma was subsequently analyzed for levels of Ca, glucose (Glu), urea nitrogen (UN), alanine aminotransferase (ALT), aspartate transaminase (AST), alkaline phosphatase (AKP), total protein (TP), albumin (Alb), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), and catalase (CAT). Statistical analysis The MIXED module in SAS 9.4 (SAS Institute Inc, Cary, NC, USA) was applied for analysis of experimental data. The DCAD levels (+338, +152, and −181) were designated as fixed effects, and goats as the random effect, then Tukey’s method was adopted to determine differences among means of the three DCAD treatments. The experiment results were expressed as mean ± standard deviation. Statistical significance was defined as P < 0.05. Results Rumen fermentation There were no significant differences in rumen pH for the same sampling intervals (0, 4, and 8 h; P > 0.05; Table 2) and all the collected mean among the HD, CON, and LD treatments (0, 4, and 8 h; P > 0.05). The variation of DCAD had no effect on ruminal BC and levels of acetic acid, propionic acid, butyric acid, total VFA (TVFA), and acetic acid/propionic acid (A/P) in the goats ( P > 0.05). Table 2 Effect of dietary cation–anion difference on the rumen pH of goats Items DCAD SEM 1 P -value HD (+338) CON +152) LD (-181) pH Sampling time interval (h) Sampling time 0 09:00 7.22 ± 0.19 7.21 ± 0.41 7.17 ± 0.36 0.14 0.97 13:00 7.10 ± 0.22 7.17 ± 0.57 6.99 ± 0.49 0.23 0.86 17:00 7.07 ± 0.25 7.20 ± 0.66 6.98 ± 0.54 0.26 0.83 4 13:00 7.05 ± 0.31 6.96 ± 0.36 7.04 ± 0.34 0.18 0.93 17:00 7.08 ± 0.38 6.96 ± 0.52 7.14 ± 0.47 0.24 0.87 8 17:00 7.15 ± 0.23 6.99 ± 0.38 7.08 ± 0.46 0.19 0.86 Mean 7.20 ± 0.22 7.18 ± 0.41 7.17 ± 0.34 0.14 0.98 BC 2 (mL/L) 44.75 ± 0.88 43.35 ± 3.65 43.10 ± 3.81 1.38 0.67 Acetic acid (mmol/L) 42.22 ± 4.86 43.45 ± 5.71 44.81 ± 6.36 2.32 0.74 Propionic acid (mmol/L) 13.00 ± 1.96 13.07 ± 1.75 12.71 ± 2.37 0.84 0.95 Butyric acid (mmol/L) 8.00 ± 1.78 8.48 ± 2.28 8.11 ± 2.02 0.83 0.91 TVFA 3 (mmol/L) 63.21 ± 8.08 65.01 ± 8.89 65.63 ± 8.10 3.41 0.87 A/P 4 3.27 ± 0.34 3.34 ± 0.36 3.67 ± 1.13 0.29 0.60 1 SEM=standard error of mean. The same as below. 2 BC=Buffering capability. 3 TVFA = acetic acid + propionic acid + butyric acid. 4 A/P = acetic acid/propionic acid. Rumen cellulolytic bacteria The relative contents of F. succinogenes , R. flavefaciens , B. fibrisolvens , and R. albus were not significantly affected among goats fed HD, CON, and LD diets ( P > 0.05; Table 3). The proportions of F. succinogenes and R. flavefaciens were markedly increased with lower DCAD compared to B. fibrisolvens and R. albus . Table 3 Effect of dietary cation–anion difference on the rumen cellulolytic bacteria communities of goats Items DCAD SEM P -value HD (+338) CON (+152) LD (-181) Fibrobacter succinogenes (%) 0.443±0.003 (48.63 %) 0.362±0.003 (41.18 %) 0.324±0.001 (62.91%) 0.098 0.70 Ruminococcus flavefaciens (%) 0.343±0.21 (37.65 %) 0.414±0.86 (47.10 %) 0.119±0.09 (23.11 %) 0.210 0.51 Butyrivibrio fibrisolvens (%) 0.12±0.12 (13.17 %) 0.085±0.07 (9.67 %) 0.065±0.03 (12.62 %) 0.033 0.59 Ruminococcus albus (%) 0.005±0.01 (0.55 %) 0.018±0.03 (2.05 %) 0.007±0.01 (1.36 %) 0.008 0.50 Sequencing and diversity of ruminal microbiota After Illumina Miseq high-throughput sequencing, a total of 698,626 valid reads were obtained with an average length of 410 bp. The VENN graph showed that there were 1075 of total 1261 OTU in 3 groups shared. There were 22, 25, 5 individual OTUs, accounting for 1.89%, 2.33%, and 0.43% for LD, HD, CON, respectively (Fig. 1). Rarefaction curves were established to quantify the OUT coverage of sampling and each rarefaction tended to be gentle with the increase of sequence number, and meanwhile, the OTU rank abundance in the 3 groups exhibited a gentler slope and wider distribution on the horizontal axis (Fig. 2). Fig. 1 The VENN graph of rumen bacterial of goats fed diets with varying cation-anion difference levels, which displaying that the disposition of operational taxonomic units (OTUs) among the control group (CON, n=6), high dietary cation-anion difference (HD, n=6) and low dietary cation-anion difference (LD, n=6) in rumen fluid microbiota. Fig. 2 Rarefaction curves (A) and the OTU rank abundance (B) of rumen bacterial of goats fed diets with varying cation-anion difference levels. The CON group: CON1, CON2, CON3, CON4, CON5, CON6. The HD group: HD1, HD2, HD3, HD4, HD5, HD6. The LD group: LD1, LD2, LD3, LD4, LD5, LD6. Alpha diversity results showed that DCAD levels did not affect Chao, Ace, Simpson, and Shannon as listed in Table 4 ( P > 0.05). The Chao, Ace, Shanno and Simpson chart of each group was also tended to be gentle corresponding to the increase of sequence number (Fig. 3). Table 4 Effect of varying dietary cation-anion difference levels on rumen bacterial community richness and diversity of goats Items Dietary treatments 1 SEM P -value HD (+338) CON (+152) LD (−181) Bacterial Richness Chao 906±89 843±129 811±116 4.28 0.333 Ace 2 900±82 834±117 815±96 4.33 0.356 Bacterial Diversity Simpson 0.027±0.02 0.033±0.01 0.028±0.01 0.04 0.760 Shannon 4.87±0.31 4.45±0.21 4.69±0.29 0.21 0.048 1 Dietary treatments: HD: High dietary cation-anion difference; CON:Control group; LD: Low dietary cation-anion difference. 2 Ace=abundance-based coverage estimator. Fig. 3 Rarefaction curves (A) and the OTU rank abundance (B) of rumen bacterial of goats fed diets with varying cation-anion difference levels. The CON group: CON1, CON2, CON3, CON4, CON5, CON6. The HD group: HD1, HD2, HD3, HD4, HD5, HD6. The LD group: LD1, LD2, LD3, LD4, LD5, LD6. According to Fig. 4, both weighted UniFrac (axis 1 + axis 2 = 66.7%, Fig. 4a) and unweighted UniFrac (axis 1 + axis 2 = 38.37%, Fig. 4b) were observed no difference in the composition of rumen microbiota for CON, HD and LD ( P > 0.05). Fig. 4 Principle coordinate analysis (PCoA) based on weighted UniFrac and unweighted UniFrac on rumen bacterial of goats fed diets with varying cation-anion difference levels. (a) PCoA based on weighted UniFrac of rumen bacterial of goats fed diets with varying cation-anion difference levels. (b) PCoA based on unweighted UniFrac of rumen bacterial of goats fed diets with varying dietary cation-anion difference levels. The percentage of variation explained by PC1 (first principal component) and PC2 (second principal component) was indicated in the axis. CON = the control group (n = 6); HD= high dietary cation-anion difference (n = 6); LD = low dietary cation-anion difference (n = 6). Taxonomic classification summary indicated that 16 phyla were tested in all samples (Fig. 5A). At the phylum level, Bacteroidetes (61.60%) was the predominant phylum followed by Firmicutes, Synergistetes, Proteobacteria, Spirochaetae, Tenericutes with average relative abundances of 25.32%, 5.84%, 1.82%, 2.08%, 1.2%, respectively, but there was no difference ( P > 0.05) among the groups on the above phylum levels except for Firmicutes, which was significantly higher in HD and LD compared to CON ( P =0.008, Table 5). At the genus level, taxon displayed that the relative abundance of 11 genera were not affected by DCAD among all samples ( P > 0.05; Fig. 5B). At the same time, Prevotella, Paraprevotella, Selenomonas, Ruminococcus, Ruminococcus, Butyrivibrio, Quinella, Fretibacterium and Treponema showed no grouping difference of the genera across treatments ( P > 0.05). Among the genera with relative abundance exceeded 0.1%, prevotella was the dominant genus in each group with the highest proportion (Table 5). Fig. 5 Distributions of microbiota at phyla and genus level. (a) Relative abundances of phyla levels are depicted as mean values for the CON, the LD (Low dietary cation-anion difference) group and HD (High dietary cation-anion difference) group. (b) Distributions of genera in rumen fluid of the CON, the LD (Low dietary cation-anion difference) group and HD (High dietary cation-anion difference) group. Table 5 Effect of varying dietary cation-cation difference on relative abundance (%) of bacteria taxa > 0.1% of average abundance in the rumen fluid of goats Phylum Genus Dietary treatments 1 SEM P -value HD CON LD Bacteroidetes 60.40±6.24 65.08±4.41 59.33±9.13 2.81 0.328 Prevotella 18.92±3.66 24.16±2.72 16.09±2.68 3.05 0.223 Paraprevotella 3.58±1.23 2.76±0.89 3.51±1.52 1.24 0.877 Firmicutes 28.43±4.90 a 18.71±5.30 b 28.81±6.08 a 2.23 0.008 Selenomonas 1.59±0.97 0.56±0.29 1.32±0.89 0.78 0.629 Ruminococcus 1.07±0.16 1.54±0.74 1.29±0.39 0.49 0.786 Succiniclasticum 1.34±0.36 0.69±0.09 0.68±0.24 0.25 0.143 Butyrivibrio 1.02±0.32 0.46±0.13 0.48±0.01 0.20 0.118 Quinella 2.29±0.37 0.71±0.30 3.73±2.15 1.27 0.277 Synergistetes 5.20±1.87 6.34±1.91 5.99±2.29 2.03 0.923 Fretibacterium 5.18±1.88 6.31±1.92 5.97±2.30 2.04 0.923 Spirochaetae 1.44±0.25 2.13±0.74 1.89±0.35 0.49 0.610 Treponema 0.72±0.16 0.98±0.52 1.39±0.35 0.37 0.458 Proteobacteria 1.10±0.42 4.49±2.38 0.67±0.07 1.40 0.140 Tenericutes 1.07±0.17 1.20±0.16 1.33±0.44 0.29 0.817 Growth performance Levels of DMI were unaffected by DCAD variations (P > 0.05; Table 6). Lower DCAD had no effect (P > 0.05) on gwowth performance of final weight, ANG, ADG, and FCR and digestibility of crude protein, NDF, ADF, and OM for goats. Table 6 Effect of dietary cation–anion difference on growth performance of goats Items DCAD SEM P -value HD (+338) CON (+152) LD (-181) Performance Initial weight (kg) 30.35 ± 3.4 30.43 ± 2.6 29.44 ± 3.7 1.36 0.86 DMI (g/d) 899.0 ± 213.6 857.5 ± 120.9 864.0 ± 124.3 64.85 0.89 Final weight (kg) 31.33 ± 3.4 31.50 ± 3.8 30.41 ± 3.3 1.48 0.82 ANG (kg) 0.98 ± 0.3 1.07 ± 0.4 0.97 ± 0.3 0.21 0.89 ADG (g/d) 65.3 ± 12.2 71.3 ± 22.7 64.7 ± 18.8 8.28 0.63 FCR 13.76 ± 6.6 12.02 ± 3.5 13.36 ± 5.9 3.00 0.81 Digestibility (%) CP (%) 56.37 ± 2.41 58.66 ± 5.91 57.68 ± 5.42 1.97 0.75 NDF (%) 50.26 ± 6.01 45.84 ± 8.39 45.58 ± 7.65 3.12 0.50 ADF (%) 51.19 ± 6.84 48.35 ± 7.74 47.59 ± 8.27 3.20 0.71 OM (%) 62.34 ± 3.59 57.73 ± 5.66 58.59 ± 3.92 2.11 0.36 Urine pH There was no difference ( P > 0.05) in urine pH for HD, CON, and LD during the observation period of 1–12 d, with pH values of 8.48, 8.43, and 8.46, respectively (Fig. 6a). Urine pH decreased slightly (8.45, 8.50, and 8.13 for HD, CON, and LD, respectively) during the dietary replacement period (13–18 d). Urine pH decreased significantly (8.43, 8.36, and 7.40 for HD, CON, and LD, respectively) with LD obviously lower than both HD and CON. During the trial period (31–45 d), compared with HD and CON, LD reduced urine pH over HD and CON (8.43, 8.42, and 6.75 for HD, CON, and LD, respectively; P < 0.05). Urine pH values were unaffected by DCAD variation between HD and CON ( P > 0.05). Furthermore, urine pH was closely related to DCAD levels within the trial period (31–45 d; R 2 = 0.9066, P < 0.05; Fig. 6b). Fig. 6a Goat urine pH for dietary cation–anion difference levels throughout the experiment Fig. 6b Association between urine pH and dietary cation-anion difference of goats in the trial period Plasma Metabolites Feeding of the LD diet resulted in the highest plasma Ca level (Table 7), which was significantly higher than both HD and CON ( P < 0.05).There were no significant differences in plasma Glu, UN, ALT, AST, AKP, TP, Alb, GSH-Px, CAT, SOD, and MDA among the DCAD treatments ( P > 0.05; Table 7). Table 7 Effect of dietary cation–anion difference on the plasma metabolites of goats Items DCAD SEM 1 P -value HD (+338) CON (+152) LD (−181) Ca (mmol/L) 2.31 ± 0.21 2.38 ± 0.17 2.91 ± 0.17 0.08 <0.01 Glu (mmol/L) 4.57 ± 1.06 5.07 ± 0.91 4.60 ± 0.36 0.34 0.56 UN (mmol/L) 6.22 ± 0.66 5.63 ± 1.09 6.24 ± 1.16 0.41 0.50 ALT (IU/L) 8.61 ± 2.55 10.22 ± 3.21 10.76 ± 3.57 1.70 0.85 AST (IU/L) 11.25 ± 3.63 13.98 ± 4.77 11.91 ± 3.41 2.01 0.80 AKP (King unit/100 mL) 20.85 ± 6.90 21.73 ± 12.57 17.81 ± 6.92 3.75 0.75 TP (g/L) 99.38 ± 14.10 112.89 ± 28.72 92.62 ± 21.62 11.47 0.37 Alb (g/L) 36.38 ± 4.34 37.11 ± 6.36 35.19 ± 6.31 2.35 0.85 GSH-Px (U/mL) 670.59 ± 127.49 755.29±296.72 709.41 ± 164.46 152.50 0.59 CAT (U/mL) 2.35 ± 0.79 1.95 ± 0.60 2.47 ± 1.03 0.66 0.84 SOD (U/mL) 68.53 ± 9.27 63.59 ± 8.59 67.98 ± 6.79 3.38 0.43 MDA (nmol/mL) 37.14 ± 5.57 34.61 ± 7.06 36.79 ± 5.94 2.54 0.75 Discussion Rumen pH has a key role in measuring rumen status and can reflect the composition and abundance of rumen microflora. Rumen health is maintained by an appropriate pH which is in range of 6.26 ~ 6.79 [ 34 ]. Rumen pH decreases when ruminants are fed high levels of concentrate. This is quite different from the acidified rumen status induced by increases in anion (Cl − and S 2− ) concentrations in the diet and which elevates Cl − and S 2− in the urine and so reduces urine pH. In this study, rumen pH was unaffected for all DCAD treatments and ruminal fluid sampling time points. This was also shown in the study of Apper-Bossard [ 35 ]. Briggs et al. [ 36 ] found that rumen BC was closely related to rumen pH, and Church [ 37 ] argued that the rumen buffer system was controlled by pH, p CO 2 , and VFA. The rumen BC can maintain a stable rumen status by keeping any sudden rise or fall in rumen pH within a certain range [ 38 ]. The rumen has a relatively stable buffer system, which is closely related to the feed, saliva, and secretion of the rumen wall and maintains the rumen internal environment. In our study, the lack of significant difference in rumen BC and pH showed that DCAD reduction did not influence the rumen internal environment. However, the rumen BC was numerically elevated with increased DCAD level on cows when adding NaHCO 3 [ 33 , 39 , 40 ]. The explanation could be attributed to the use of a different animal species and different dietary ingredients. Generally, up to now there has been insufficient information on rumen BC in goats, and further study is needed due to the importance of BC for rumen status. The rumen VFA profile is mainly impacted by the proportion of concentrate and forage in the diet. Increasing DCAD, by adding K and Na, had no effect on rumen VFA concentration [ 41 ]. Tucker et al. [ 42 ] reported that the rumen VFA profile was unaffected by DCAD levels of − 100, 0, 100, and 200. Apper-Bossard et al. [ 35 ] found no significant difference in VFA concentration with varying DCAD. These results are consistent with the present study in which rumen VFA concentration was not significantly affected by DCAD level. Correspondingly, the VFA profiles and A/P levels were unaffected by DCAD. This indicates that the rumen fermentation pattern was unaltered by the three DCAD treatments. In the current study, DCAD variation had no influence on the populations of B. fibrisolvens , F. succinogenes , R. flavefaciens , and R. albus . This result indicates that reducing DCAD would not affect the growth and colonization of rumen cellulolytic bacteria. This is likely associated with stable rumen pH and VFA maintained by the constant ratio of concentrate to roughage (30:70) for the three DCAD diets used in this study. Grilli et al. [ 43 ] reported that a high proportion of maize disturbed the ruminal bacterial ecosystem of goats. Wang et al. [ 44 ] and Li et al. [ 45 ] noted that the relative quantity of ruminal B. fibrisolvens , F. succinogenes , R. flavefaciens , and R. albus was improved with decreasing rumen pH. In our most recent study (unpublished data) with dairy goats as experimental animals fed 4 DCAD levels at 349, 120, and − 167, respectively, rumen BC was not influenced. This result also supports the conclusions in the present study. The microbiota composition of the gastrointestinal tract (GIT) influence the health of animals as well as productivity [ 46 ], the structure and composition of ruminant microbial community are often devoted to evaluating the health status of the host and ensuring the healthy development of the rumen. Furthermore, the diversity and composition of the GIT microbiota can be influenced by many factors including age, diet, feeding management and feed additives [ 47 , 48 ]. Microbial richness in rumen will be altered with dietary composition [ 49 , 50 ]. Dietary nutrients are fermented by rumen rumen microbial, such as bacteria, fungi and protozoa, and then degraded into VFA and MCP to provide energy for ruminants [ 51 ] and to guarantee the healthy and stable rumen environment [ 52 , 53 ]. In such reactions, rumen pH plays a decisive role in the composition and abundance of rumen microflora, and is an important indicator reflecting whether the composition and abundance of rumen microflora are normal [ 54 , 55 ]. Similarly, rumen microbial is also influenced by animal species, diet composition and different ages [ 56 – 58 ]. The study of Zhang et al. [ 59 ] showed that rumen bacterial species, Chao index and Ace index were affected by rumen pH which can alter the bacterial community structure. Accordingly, Guo [ 60 ] found that decreased rumen pH would up-regulate bacterial diversity, composition and abundance of bacteria. In this experiment, rumen pH was not impacted by DCAD level, which exactly explained why the Chao index, Ace index, Simpson index and Beta diversity of the three groups were homogeneous. The Shannon index of the HD group was the highest, possibly because NaHCO 3 was added as a buffer to neutralize gastric acid and was essential for stomach health by creating a suitable internal environment for rumen microorganisms. Reducing DCAD had little effect on Shannon index. In addition, the dominant bacteria of the three groups in this experiment were Bacteroidetes followed by Firmicutes and Synergistetes , which was coincide with the results of previous studies on the basis of phylum [ 61 – 63 ]. In terms of genus level, the relative abundance of Prevotella , one of the primary protein-degrading microorganisms of Qianbei miscellaneous goats, was the highest, which was supported by the results of other ruminant studies [ 64 ]. The Firmicutes are a kind of intestinal bacteria related to obesity can degrade insoluble fiber and play an important role in the process of substance metabolism in rumen. The abundance of Firmicutes in HD and LD were 51.95% and 53.98% higher than CON, respectively in the study. The up-regulation in Firmicutes abundance might be due to our application of a high forage diet. In summary, neither the reduction of DCAD have a negative effect on the bacterial diversity nor changed the content of the main bacterial genus. As described above, rumen pH, BC, VFA, cellulolytic bacteria population and rumen microflora diversity are crucial in the fermentation status of ruminants. The unaffected these parameters in the present study provide further reliable information and the feasibility on feeding a low-DCAD diet to goats. Level of feed intake is the most important prerequisite for animal growth performance. Generally, pure anionic salt exerts some reduction on feed intake when it was simply mixed into diet, due to its bitter taste and poor palatability [ 65 , 66 ]. Therefore, improving palatability of anionic salt is important for DMI and growth performance. Our previous study [ 67 ] showed that DMI of goats fed a low-DCAD did not decrease because the anionic salts were mixed with molasses and dried distillers grains with solubles. Takagi and Block [ 68 , 69 ] also observed that reducing DCAD did not impact DMI containing anionic salts when feeding a total mixture ration. Diets were pelleted in our study, and therefore, they were unaffected for goats fed diet HD, CON, and LD. This indicates that DMI is unaffected by anionic salts inclusion as long as the bitter taste is concealed. The levels of DCAD had no effect on goat final weights. This can be attributed to the similar DMI level and possibly because the goats in this experiment were a local breed, with their adult steady body weight averaging as much as 35 kg, and thus there was limited potential for body weight gain. Accordingly, ADG and FCR did not show difference among goats provided HD, CON, or LD diets. Nutrients digestibility can be used to measure the digestion and absorption degree of a diet. Correlative analysis in the study demonstrated the digestibility of CP, NDF, ANF, and OM were unaffected for goats fed the three DCAD diets. Apper-Bossard et al. [ 35 ] reached similar conclusions. Positive DCAD diet is beneficial to the growth and reproduction of rumen cellulolytic bacteria, and can maintain the activity of digestive enzymes in the digestive tract, thus improving nutrient digestibility [ 70 ]. However, different levels of DCAD did not alter the digestibility of CP, NDF, ADF and OM with the rumen pH and rumen cellulolytic bacteria community remained unchanged in this research. Urine pH is a useful indicator to monitor the effect of a reduced DCAD diet on acid–base balance in goats and sheep [ 71 , 72 ], dairy cows [ 8 , 73 , 74 ], and buffalo [ 4 ]. This phenomenon can be explained using the strong ion difference theory of Stewart [ 75 ], who argued that with reductions of DCAD, the concentration of anions in blood would increase and cause the kidney to expel redundant H + in urine, resulting in lower urine pH. The recommended urine pH is 6.5–6.8, because too low a level would exert a burden on the kidneys [ 76 – 78 ]. Our results showed that urine pH value in goats fed LD was lower than HD and CON. This is accordant with the recommended level, and there is a strong association between DCAD and urine pH in the trial period, suggesting that the LD level is appropriate for the diet of goats. Muscle contraction, conduction of nervous impulses, and signal transduction are closely dependent on blood Ca homeostasis. Following the study of Block [ 2 ] and subsequent results of ruminant researchers [ 71 , 79 , 80 ], reducing the DCAD level has been the most commonly used strategy to increase blood Ca levels in transition mammary animals [ 81 ]. Our previous study showed that reducing DCAD could increase the plasma Ca concentration of female goats [ 67 ]. In the current experiment, the LD caused higher plasma Ca level than HD and CON by 25.97% and 22.27%, respectively, indicating more stable blood Ca homeostasis. Horst et al. [ 82 ] and Goff and Horst [ 83 ] claimed this may be because LD-induced acidic status enhanced Ca absorption in the gastro-intestine and also increased Ca resorption in the bone, facilitating Ca matrix flow into blood for easier transfer from lumen to blood. In the review of Khanal and Nemere [ 84 ] who described three steps for Ca absorption. First, Ca 2+ influx occurs at the apical membrane via epithelial Ca 2+ channels, which include the transient receptor potential vanilloid receptor 6 (TRPV6). This step is considered to be rate-limiting for transcellular Ca 2+ transport [ 85 ]. Second, intracellular diffusion is facilitated by the vitamin D-dependent calcium binding protein D9k (CaBP-D9k) [ 86 ]. Last, extrusion at the basolateral membrane is achieved by either the Na + /Ca 2+ exchanger1 (NCX1) or the plasma membrane calcium ATPase 1b (PMCA1b) [ 87 ]. The proteins of TRPV6, CaBP-D9k, and PMCA1b are believed to be the three key factors involved in the Ca absorption process, therefore, we speculate that TRPV6, CaBP-D9k, and PMCA1b expression levels in the intestine might be upregulated for animals fed the LD diet. However, a lack of data on TRPV6, CaBP-D9k, and PMCA1b expression in the intestine limits our further discussion. Future work is needed in this area. Blood measurements are useful to reflect the metabolic status of animals. Our results showed that all plasma levels of Glu, UN, ALT, AST, AKP, TP, Alb, SOD, GSH-Px, MDA, and CAT were unaffected by DCAD variation. This indicates that reducing DCAD had no effect on nutrient metabolite processes in the plasma. This is supported by previous study. Melendez and Poock [ 9 ] reported that lowering DCAD had little effect on blood Alb. Wu et al. [ 67 ] found that DCAD level (+ 300, + 150, 0, and − 150) had no significant effect on plasma GSH-Px and MDA content in female goats. Conclusion Reducing DCAD has little influence on rumen status and rumen microbiota, showing no harmful to rumen fermentation of goats. Blood Ca level is increased and urine pH is decreased by DCAD reduction. These results indicate the feasibility of feeding a low-DCAD diets to goats. Abbreviations DCAD Dietary cation-anion difference; HD:High DCAD; CON:Control; LD:Low DCAD; DM:Dry matter; DMI:Dry matter intake; NDF:Neutral detergent fiber; ADF:Acid detergent fiber; AIA:Acid insoluble ash; VFA:Volatile fatty acid; TVFA:Total volatile fatty acid; A/P:Acetate/Propionate; NH 3 -N:Ammonia nitrogen; CP:Crude protein; OM:Organic matter; ANG:Average net gain; ADG:Average daily gain; F/G:Feed/Gain; FCR:Feed conversion ratio; BC:Buffer capability; Glu:Glucose; UN:Urea nitrogen; ALT:Alanine aminotransferase; AST:Aspartate transaminase; SOD:Superoxide dismutase; AKP:Alkaline phosphatase; ALB:Albumin; TP:Total protein; GSH-Px:Glutathione peroxidase; MDA:Malondialdehyde; CAT:Catalase; SEM:Standard error of means Declarations Availability of data and materials All data generated or analyzed during this study are included in this published article. Ethics approval All procedures with animals received prior approval from the Animal Care and Use Committee of the Guizhou University and followed the regulations and guidelines for animal care and welfare established by the committee. Consent for publication Not applicable. Competing interests All authors declare that there are no present or potential conflicts of interest among the authors and other people or organizations that could inappropriately bias their work. Funding This study is financially funded by National Natural Science Foundation of China (31960674), Science and Technology Project of Guizhou Province ([2018]1403), and the Construction Program of Biology First-class Discipline in Guizhou (GNYL[2017]009). Authors’ contributions K.Y., X.T., and W.W. conceived and designed the experiment. S.J., L.S., E.H., F.W., Z.G., and Z.M. carried out the farm and the collection of samples. K.Y. and S.J. gathered and analyzed the data, and both took charge for data interpretation and sequencing data (figures and tables), and K.Y. and X.T. wrote the manuscript. T.H. made feasible suggestions for the manuscript. WW acted as overall study director. All authors have read and approved the final manuscript. Acknowledgement The authors thank the Animal Nutrition Laboratory of Guizhou University for providing the feeding trial site and chemical analysis facilities for this research. The authors also thank International Science Editing for editing this manuscript ( http://www.internationalscienceediting.com ). References Riond JL. Animal nutrition and acid-base balance. Eur J Nutrit. 2001;40:245–54. Block E. Manipulating dietary anions and cations for prepartum dairy cows to reduce incidence of milk fever. J Dairy Sci. 1984;67:2939–48. Graham-Thiers PM, Kronfeld DS. Dietary protein influences acid-base balance in sedentary horses. J Equine Vet Sci. 2005;25:434–8. 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J Dairy Sci. 1991c;74:4225–37. Sharif M, Shahzad MA, Mahr-un-Nisa, Sarwar M. Influence of varying levels of dietary cation anion difference on ruminal characteristics, nitrogen metabolism and in situ digestion kinetics in buffalo bulls. Anim Sci J. 2010;81:657–65. Takagi H, Block E. Effects of manipulating dietary cation-anion balance on macromineral balance in sheep. J Dairy Sci. 1991a;74:4202–14. Liesegang A. Influence of anionic salts on bone metabolism in periparturient dairy goats and sheep. J Dairy Sci. 2008;91:2449–60. Wu WX, Liu JX, Xu GZ, Ye JA. Calcium homeostasis, acid–base balance, and health status in periparturient Holstein cows fed diets with low cation–anion difference. Livest Sci. 2008;117:7–14. Rodrigues RO, Cooke RF, Rodrigues SMB, Bastos LN, de Camargo VFS, Gomes KS, et al. Reducing prepartum urine pH by supplementing anionic feed ingredients: Effects on physiological and productive responses of Holstein × Gir cows. J Dairy Sci. 2018;101:9296–308. Stewart PA. Modern quantitative acid-base chemistry. Can J Physiol Pharm. 1983;61:1444–61. DeGaris PJ, Lean IJ. Milk fever in dairy cows: A review of pathophysiology and control principles. Vet J. 2008;176:58–69. Seifi HA, Mohri M, Farzaneh N, Nemati H, Nejhad SV. Effects of anionic salts supplementation on blood pH and mineral status, energy metabolism, reproduction and production in transition dairy cows. Res Vet Sci. 2010;89:72–7. Grünberg W, Donkin SS, Constable PD. Periparturient effects of feeding a low dietary cation-anion difference diet on acid-base, calcium, and phosphorus homeostasis and on intravenous glucose tolerance test in high-producing dairy cows. J Dairy Sci. 2011;94:727–45. Espino L, Guerrero F, Suarez ML, Santamarina G, Goicoa A, Fidalgo LE. Long-term effects of dietary anion-cation balance on acid-base status and bone morphology in reproducing ewes. J Vet Med A Physiol Pathol Clin Med. 2003;50:488–95. Roche JR, Petch S, Kay JK. Manipulating the dietary cation-anion difference via drenching to early-lactation dairy cows grazing pasture. J Dairy Sci. 2005;88:264–76. USDA. Changes in the U.S. dairy cattle industry, 1991–2007, USDA, APHIS: VS CEAH, National Animal Health Monitoring System, Fort Collins, CO. 2007, p. 480. Horst RL, Goff JP, Reinhardt TA, Buxton DR. Strategies for preventing milk fever in dairy cattle. J Dairy Sci. 1997;80:1269–80. Goff JP, Horst RL. Role of acid-base physiology on the pathogenesis of parturient hypocalcemia (milk fever)-The DCAD theory in principle and practice. Acta Vet Scand. 2003;97:1–66. Khanal RC, Nemere I. Regulation of intestinal calcium transport. Annu Rev Nutr. 2008;28:179–96. Hoenderop JG, Nilius B, Bindels RJ. Calcium absorption across epithelia. Physiol Rev. 2005;85:373–422. Ko SH, Choi KC, Oh GT, Jeung EB. Effect of dietary calcium and 1,25-(OH) 2 D 3 on the expression of calcium transport genes in calbindin-D9k and-D28k double knockout mice. Biochem Bioph Res Co. 2009;379:227–32. Choi KC, An BS, Yang H, Jeung EB. Regulation and molecular mechanisms of calcium transport genes: do they play a role in calcium transport in the uterine endometrium. J Physiol Pharmacol. 2011;62:499–504. Supplementary Files renamed52161.pdf Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {\"props\":{\"pageProps\":{\"initialData\":{\"identity\":\"rs-41136\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":true,\"archivedVersions\":[],\"articleType\":\"Research\",\"associatedPublications\":[],\"authors\":[{\"id\":805439,\"identity\":\"63acb87b-b4a4-4f83-bd4a-bcbe7900f276\",\"order_by\":0,\"name\":\"Kang Yang\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Guizhou University\",\"correspondingAuthor\":false,\"submittingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Kang\",\"middleName\":\"\",\"lastName\":\"Yang\",\"suffix\":\"\"},{\"id\":805440,\"identity\":\"f4451085-95d8-48f1-b856-e739c1c7038d\",\"order_by\":1,\"name\":\"Xingzhou Tian\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Guizhou University\",\"correspondingAuthor\":false,\"submittingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Xingzhou\",\"middleName\":\"\",\"lastName\":\"Tian\",\"suffix\":\"\"},{\"id\":805441,\"identity\":\"0e2051da-a26a-4ec6-aeb6-b2d7f4839569\",\"order_by\":2,\"name\":\"Shiyan Jian\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Guizhou University\",\"correspondingAuthor\":false,\"submittingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Shiyan\",\"middleName\":\"\",\"lastName\":\"Jian\",\"suffix\":\"\"},{\"id\":805442,\"identity\":\"57a2eebb-742c-4ee2-a6f1-57da3d867aac\",\"order_by\":3,\"name\":\"Lun Sun\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Guizhou University\",\"correspondingAuthor\":false,\"submittingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Lun\",\"middleName\":\"\",\"lastName\":\"Sun\",\"suffix\":\"\"},{\"id\":805443,\"identity\":\"f2dcf5ae-467e-45e5-a47c-aba61fa705cc\",\"order_by\":4,\"name\":\"E Han\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Guizhou University\",\"correspondingAuthor\":false,\"submittingAuthor\":false,\"prefix\":\"\",\"firstName\":\"E\",\"middleName\":\"\",\"lastName\":\"Han\",\"suffix\":\"\"},{\"id\":805444,\"identity\":\"3c59a76e-79d2-4393-beb6-cc19299545b3\",\"order_by\":5,\"name\":\"Fei Wang\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Guizhou University\",\"correspondingAuthor\":false,\"submittingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Fei\",\"middleName\":\"\",\"lastName\":\"Wang\",\"suffix\":\"\"},{\"id\":805445,\"identity\":\"70ac0790-9626-43f4-a0fb-4873084f3248\",\"order_by\":6,\"name\":\"Ziyi Guo\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Guizhou University\",\"correspondingAuthor\":false,\"submittingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Ziyi\",\"middleName\":\"\",\"lastName\":\"Guo\",\"suffix\":\"\"},{\"id\":805446,\"identity\":\"014d5048-61af-4c89-9a2c-01be9a5c3a51\",\"order_by\":7,\"name\":\"Zhengfa Ma\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Guizhou University\",\"correspondingAuthor\":false,\"submittingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Zhengfa\",\"middleName\":\"\",\"lastName\":\"Ma\",\"suffix\":\"\"},{\"id\":805447,\"identity\":\"e84c2cb9-9bbf-4171-80cc-6206aae3efda\",\"order_by\":8,\"name\":\"Tengbing He\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Guizhou University\",\"correspondingAuthor\":false,\"submittingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Tengbing\",\"middleName\":\"\",\"lastName\":\"He\",\"suffix\":\"\"},{\"id\":805448,\"identity\":\"d57693a2-6e79-4dd6-aebf-a3e8e30c5166\",\"order_by\":9,\"name\":\"Wenxuan Wu\",\"email\":\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAs0lEQVRIiWNgGAWjYLCCDxDKgHgdjDNI1sLMQ5IWgxs5ZtI2v+oSG9ibt0kw1NhEE9Zy5oyZdG4fW2IDz7EyCYZjabkNhLSYHe/dJp3bw5PYIJFjJsHYcJgILYd5t0lb9kgkNsi/IVYLyBaGHwZAW3iI1GJ/5vxny96GBOM2nrRiiwRi/CI5Iy3xxo8/dbL97Ic33vhQY0NYCxgwtjEwsIEYCUQpB4M/xCsdBaNgFIyCEQgAzBk6zYgvh94AAAAASUVORK5CYII=\",\"orcid\":\"https://orcid.org/0000-0001-5037-8771\",\"institution\":\"Guizhou University\",\"correspondingAuthor\":true,\"submittingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Wenxuan\",\"middleName\":\"\",\"lastName\":\"Wu\",\"suffix\":\"\"}],\"badges\":[],\"createdAt\":\"2020-07-11 12:37:28\",\"currentVersionCode\":1,\"declarations\":\"\",\"doi\":\"10.21203/rs.3.rs-41136/v1\",\"doiUrl\":\"https://doi.org/10.21203/rs.3.rs-41136/v1\",\"draftVersion\":[],\"editorialEvents\":[],\"editorialNote\":\"\",\"failedWorkflow\":false,\"files\":[{\"id\":1556881,\"identity\":\"bb124031-ca83-4061-931b-140cd50aba13\",\"added_by\":\"auto\",\"created_at\":\"2020-07-14 19:36:19\",\"extension\":\"jpg\",\"order_by\":1,\"title\":\"Figure 1\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":27370,\"visible\":true,\"origin\":\"\",\"legend\":\"The VENN graph of rumen bacterial of goats fed diets with varying cation-anion difference levels, which displaying that the disposition of operational taxonomic units (OTUs) among the control group (CON, n=6), high dietary cation-anion difference (HD, n=6) and low dietary cation-anion difference (LD, n=6) in rumen fluid microbiota.\",\"description\":\"\",\"filename\":\"1.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-41136/v1/1.jpg\"},{\"id\":1556882,\"identity\":\"a9dca35d-0e77-4580-ac07-1ae04f5a53fd\",\"added_by\":\"auto\",\"created_at\":\"2020-07-14 19:36:19\",\"extension\":\"jpg\",\"order_by\":2,\"title\":\"Figure 2\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":38251,\"visible\":true,\"origin\":\"\",\"legend\":\"Rarefaction curves (A) and the OTU rank abundance (B) of rumen bacterial of goats fed diets with varying cation-anion difference levels. The CON group: CON1, CON2, CON3, CON4, CON5, CON6. The HD group: HD1, HD2, HD3, HD4, HD5, HD6. The LD group: LD1, LD2, LD3, LD4, LD5, LD6.\\n\\n\",\"description\":\"\",\"filename\":\"2.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-41136/v1/2.jpg\"},{\"id\":1556883,\"identity\":\"fb7ed73e-26e5-4895-87e7-cdb199f555ea\",\"added_by\":\"auto\",\"created_at\":\"2020-07-14 19:36:19\",\"extension\":\"jpg\",\"order_by\":3,\"title\":\"Figure 3\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":75346,\"visible\":true,\"origin\":\"\",\"legend\":\"Rarefaction curves (A) and the OTU rank abundance (B) of rumen bacterial of goats fed diets with varying cation-anion difference levels. The CON group: CON1, CON2, CON3, CON4, CON5, CON6. The HD group: HD1, HD2, HD3, HD4, HD5, HD6. The LD group: LD1, LD2, LD3, LD4, LD5, LD6.\\n\\n\",\"description\":\"\",\"filename\":\"3.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-41136/v1/3.jpg\"},{\"id\":1556884,\"identity\":\"c026d6cf-d8bf-4de4-aa83-3170d31260dc\",\"added_by\":\"auto\",\"created_at\":\"2020-07-14 19:36:20\",\"extension\":\"jpg\",\"order_by\":4,\"title\":\"Figure 4\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":28157,\"visible\":true,\"origin\":\"\",\"legend\":\"Principle coordinate analysis (PCoA) based on weighted UniFrac and unweighted UniFrac on rumen bacterial of goats fed diets with varying cation-anion difference levels. (a) PCoA based on weighted UniFrac of rumen bacterial of goats fed diets with varying cation-anion difference levels. (b) PCoA based on unweighted UniFrac of rumen bacterial of goats fed diets with varying dietary cation-anion difference levels. The percentage of variation explained by PC1 (first principal component) and PC2 (second principal component) was indicated in the axis. CON = the control group (n = 6); HD= high dietary cation-anion difference (n = 6); LD = low dietary cation-anion difference (n = 6).\",\"description\":\"\",\"filename\":\"4.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-41136/v1/4.jpg\"},{\"id\":1556885,\"identity\":\"e0a07e2f-443a-441d-ab95-689dd93b05e0\",\"added_by\":\"auto\",\"created_at\":\"2020-07-14 19:36:20\",\"extension\":\"jpg\",\"order_by\":5,\"title\":\"Figure 5\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":32917,\"visible\":true,\"origin\":\"\",\"legend\":\"Distributions of microbiota at phyla and genus level. (a) Relative abundances of phyla levels are depicted as mean values for the CON, the LD (Low dietary cation-anion difference) group and HD (High dietary cation-anion difference) group. (b) Distributions of genera in rumen fluid of the CON, the LD (Low dietary cation-anion difference) group and HD (High dietary cation-anion difference) group.\\n\\n\",\"description\":\"\",\"filename\":\"5.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-41136/v1/5.jpg\"},{\"id\":1556886,\"identity\":\"089be30a-20b0-46b2-aa61-1b8443531cf5\",\"added_by\":\"auto\",\"created_at\":\"2020-07-14 19:36:20\",\"extension\":\"jpg\",\"order_by\":6,\"title\":\"Figure 6\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":40174,\"visible\":true,\"origin\":\"\",\"legend\":\"6a Goat urine pH for dietary cation–anion difference levels throughout the experiment\\n6b Association between urine pH and dietary cation-anion difference of goats in the trial period\",\"description\":\"\",\"filename\":\"6.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-41136/v1/6.jpg\"},{\"id\":13551667,\"identity\":\"59052941-c4c1-48be-915c-055817c4f653\",\"added_by\":\"auto\",\"created_at\":\"2021-09-17 02:29:36\",\"extension\":\"pdf\",\"order_by\":0,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"manuscript-pdf\",\"size\":635027,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"manuscript.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-41136/v1/ade9177f-67df-4b9c-9851-ba2489f5ad1d.pdf\"},{\"id\":1556888,\"identity\":\"cf1750a4-842d-448c-96c8-6ef4823a2ab9\",\"added_by\":\"auto\",\"created_at\":\"2020-07-14 19:36:21\",\"extension\":\"pdf\",\"order_by\":1,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"supplement\",\"size\":821238,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"renamed52161.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-41136/v1/renamed52161.pdf\"}],\"financialInterests\":\"\",\"formattedTitle\":\"Reducing dietary cation–anion difference seldom affects rumen fermentation, cellulolytic bacteria populations, and microbiota in goats\",\"fulltext\":[{\"header\":\"Background\",\"content\":\" \\u003cp\\u003eDietary cation\\u0026ndash;anion difference (DCAD; mmol/kg dry matter [DM]) refers to the difference between the number of millimoles of major cations (Na\\u003csup\\u003e+\\u003c/sup\\u003e and K\\u003csup\\u003e+\\u003c/sup\\u003e) and major anions (Cl\\u003csup\\u003e\\u0026minus;\\u003c/sup\\u003e and S\\u003csup\\u003e2\\u0026minus;\\u003c/sup\\u003e) of per kg of DM in the diet [\\u003cspan citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e1\\u003c/span\\u003e]. Variations in DCAD enables maintenance of electrolyte balance and osmotic pressure, improving the health status of animals. The initial benefit of feeding a low-DCAD diet was reported by Block [\\u003cspan citationid=\\\"CR2\\\" class=\\\"CitationRef\\\"\\u003e2\\u003c/span\\u003e], who observed that treatment with \\u0026minus;\\u0026thinsp;172.3 (mmol/kg DM) DCAD could prevent hypocalcemia compared to a control DCAD of +\\u0026thinsp;448.6 (mmol/kg DM). The DCAD level has been an important parameter in the process of formulating diets in recent years [\\u003cspan additionalcitationids=\\\"CR4 CR5 CR6\\\" citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e3\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR7\\\" class=\\\"CitationRef\\\"\\u003e7\\u003c/span\\u003e]. Studies have shown that diets with a lower DCAD could enhance the health and extend the economic life of transition mammary animals [\\u003cspan additionalcitationids=\\\"CR9\\\" citationid=\\\"CR8\\\" class=\\\"CitationRef\\\"\\u003e8\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e10\\u003c/span\\u003e]. Recently, attention was given to the interaction of DCAD with calcium (Ca) concentration[\\u003cspan citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e11\\u003c/span\\u003e], cholecalciferol/calcidiol[\\u003cspan citationid=\\\"CR12\\\" class=\\\"CitationRef\\\"\\u003e12\\u003c/span\\u003e], 5-hydroxy-l-tryptophan [\\u003cspan citationid=\\\"CR13\\\" class=\\\"CitationRef\\\"\\u003e13\\u003c/span\\u003e], vitamin D [\\u003cspan additionalcitationids=\\\"CR15\\\" citationid=\\\"CR14\\\" class=\\\"CitationRef\\\"\\u003e14\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR16\\\" class=\\\"CitationRef\\\"\\u003e16\\u003c/span\\u003e], and duration [\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR18\\\" class=\\\"CitationRef\\\"\\u003e18\\u003c/span\\u003e] of blood Ca level increases. Results of these studies indicated that lower DCAD in association with the above factors was effective in improving homeostasis of peripheral blood Ca. Most recently, Santos et al. [\\u003cspan citationid=\\\"CR19\\\" class=\\\"CitationRef\\\"\\u003e19\\u003c/span\\u003e] and Lean et al. [\\u003cspan citationid=\\\"CR20\\\" class=\\\"CitationRef\\\"\\u003e20\\u003c/span\\u003e] used meta-analyses to determine the effects of varying DCAD on the performance, production, and health of cows.\\u003c/p\\u003e \\u003cp\\u003eRuminant diets usually include up to 70% roughage and so are fiber-rich. As the most important digestive organ, the rumen is the main site for digestion and utilization of nutrient, especially for degradation of cellulose by cellulolytic bacteria. Among rumen measurements, pH is the key parameter determining rumen fermentation status and is often lowered when ruminants are fed high levels of concentrate, resulting in ruminal acidosis [\\u003cspan additionalcitationids=\\\"CR22\\\" citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e21\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR23\\\" class=\\\"CitationRef\\\"\\u003e23\\u003c/span\\u003e]. Bacteria account for 95% of the total amount of rumen microorganisms [\\u003cspan citationid=\\\"CR24\\\" class=\\\"CitationRef\\\"\\u003e24\\u003c/span\\u003e], and thus are the main factor to modulate digestive and metabolic activity of the rumen[\\u003cspan citationid=\\\"CR25\\\" class=\\\"CitationRef\\\"\\u003e25\\u003c/span\\u003e]. \\u003cem\\u003eButyrivibrio fibrisolvens\\u003c/em\\u003e, \\u003cem\\u003eFibrobacter succinogenes\\u003c/em\\u003e, \\u003cem\\u003eRuminococcus flavefaciens\\u003c/em\\u003e, and \\u003cem\\u003eRuminococcus albus\\u003c/em\\u003e are reported the four most important cellulolytic bacteria for digestion and utilization of fiber in the rumen [\\u003cspan additionalcitationids=\\\"CR27 CR28\\\" citationid=\\\"CR26\\\" class=\\\"CitationRef\\\"\\u003e26\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR29\\\" class=\\\"CitationRef\\\"\\u003e29\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eHowever, to our knowledge, there is less information on the rumen fermentation, cellulolytic bacteria populations and microbiota for goats fed a low-DCAD diet, therefore, the present study was conducted to evaluate the effect of a low-DCAD on the above-mentioned parameters of rumen pH, buffering capability, volatile fatty acids of acid, propionic acid, butyric acid, total volatile fatty acids, and acetic acid/propionic acid profiles; ruminal cellulolytic bacteria populations of \\u003cem\\u003eFibrobacter succinogenes\\u003c/em\\u003e, \\u003cem\\u003eRuminococcus flavefaciens\\u003c/em\\u003e, \\u003cem\\u003eButyrivibrio fibrisolvens\\u003c/em\\u003e and \\u003cem\\u003eRuminococcus albus\\u003c/em\\u003e, and microbiota. Growth performance, acid-base balance, plasma calcium level and metabolites were also measured. The results should provide a comprehensive evaluation of the feasibility of feeding a low-DCAD diet to goats.\\u003c/p\\u003e \"},{\"header\":\" Materials And Methods\",\"content\":\"\\u003ch2\\u003e\\u003cstrong\\u003eExperimental design and animal management\\u003c/strong\\u003e\\u003c/h2\\u003e\\n\\u003cp\\u003eThe animal treatment procedures were approved by the local animal care and use committee. Using a randomized block design, 18 Qianbei miscellaneous goats (a native goat breed in the southwest of China; 30.07 kg initial weight and aged 13 months) were allotted to 3 treatments of six replicates of 1 goat per replicate. Animals were fed one of three diets with different DCAD levels (mmol/kg DM): +350 (HD), +100 (CON), and \\u0026minus;150 (LD). Diets consisted of peanut straw (\\u003cem\\u003eArachis hypogaea\\u003c/em\\u003e), faba bean straw (\\u003cem\\u003eVicia faba\\u003c/em\\u003e) and concentrate which were mixed with NaHCO\\u003csub\\u003e3\\u003c/sub\\u003e (HD) or NH\\u003csub\\u003e4\\u003c/sub\\u003eCl (LD) and were pelleted (4 mm diameter), with a concentrate: roughage ratio of 30:70.\\u003c/p\\u003e\\n\\u003cp\\u003eGoats were fed in separate metabolic cages. The experiment duration was 45 d including a 30-d adaption period and 15-d trial period. The adaption period was divided into three stages. In the first stage (1\\u0026ndash;12 d), goats were observed for health condition and treated for parasites and disinfected. During the second stage (13\\u0026ndash;18 d), goats were allowed to adjust to their respective diets. In the third stage (19\\u0026ndash;30 d), steady DM intake (DMI) was determined for individual goats. After that, in the trial period (31\\u0026ndash;45 d), goats were fed the treatment diets strictly according to the established DMI at 09:00 and 18:00. All goats had free access to water during the whole experiment. Ingredients and nutrient levels of diets for goats are shown in Table 1. The actual DCAD levels were measured as +338, +152, and \\u0026minus;181, showing slight differences from the designed values of +350, +100, and \\u0026minus;150 for HD, CON, and LD, respectively.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eTable 1 \\u003c/strong\\u003eIngredients and nutrient compositions of diet for goat\\u003c/p\\u003e\\n\\u003ctable width=\\\"550\\\"\\u003e\\n\\u003ctbody\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd rowspan=\\\"2\\\" width=\\\"208\\\"\\u003e\\n\\u003cp\\u003eItems\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd colspan=\\\"3\\\" width=\\\"342\\\"\\u003e\\n\\u003cp\\u003eDCAD\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003eHD\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003eCON\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003eLD\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"208\\\"\\u003e\\n\\u003cp\\u003eIngredients\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"208\\\"\\u003e\\n\\u003cp\\u003eConcentrate (%)\\u003csup\\u003e1\\u003c/sup\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e30\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e30\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e30\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"208\\\"\\u003e\\n\\u003cp\\u003ePeanut straw (%)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e50\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e50\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e50\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"208\\\"\\u003e\\n\\u003cp\\u003eFaba bean straw (%)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e20\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e20\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e20\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"208\\\"\\u003e\\n\\u003cp\\u003eNaHCO\\u003csub\\u003e3\\u003c/sub\\u003e (g/d)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e12\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e--\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e--\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"208\\\"\\u003e\\n\\u003cp\\u003eNH\\u003csub\\u003e4\\u003c/sub\\u003eCl (g/d)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e--\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e--\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e15\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"208\\\"\\u003e\\n\\u003cp\\u003eNutrient levels\\u003csup\\u003e2\\u003c/sup\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"208\\\"\\u003e\\n\\u003cp\\u003eDM (%)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e93.70\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e93.77\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e93.90\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"208\\\"\\u003e\\n\\u003cp\\u003eCP (% DM)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e13.40\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e13.64\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e14.21\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"208\\\"\\u003e\\n\\u003cp\\u003eNDF (% DM)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e39.40\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e39.64\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e39.82\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"208\\\"\\u003e\\n\\u003cp\\u003eADF (% DM)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e30.35\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e30.62\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e30.64\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"208\\\"\\u003e\\n\\u003cp\\u003eOM (% DM)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e88.02\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e87.03\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e87.71\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"208\\\"\\u003e\\n\\u003cp\\u003eCa (% DM)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e0.67\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e0.64\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e0.68\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"208\\\"\\u003e\\n\\u003cp\\u003eP (% DM)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e0.48\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e0.49\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e0.49\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"208\\\"\\u003e\\n\\u003cp\\u003eNa (% DM)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e0.52\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e0.19\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e0.14\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"208\\\"\\u003e\\n\\u003cp\\u003eK (% DM)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e1.08\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e0.98\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e0.87\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"208\\\"\\u003e\\n\\u003cp\\u003eCl (% DM)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e0.23\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e0.27\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e1.25\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"208\\\"\\u003e\\n\\u003cp\\u003eS (% DM)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e0.16\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e0.17\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e0.18\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"208\\\"\\u003e\\n\\u003cp\\u003eDCAD (mmol/kg DM)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e+338\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e+152\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e-181\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003c/tbody\\u003e\\n\\u003c/table\\u003e\\n\\u003cp\\u003e\\u003csup\\u003e1 \\u003c/sup\\u003eComposition and proportion (%): corn 51.07, soybean meal 24.82, wheat bran 11.19, rapeseed meal 8.07, CaHPO\\u003csub\\u003e4\\u003c/sub\\u003e 0.45, lysine 0.27, methionine 0.29, NaCl 0.77, and premix 3.06.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003csup\\u003e2 \\u003c/sup\\u003eActually measured values.\\u003c/p\\u003e\\n\\u003ch2\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/h2\\u003e\\n\\u003ch2\\u003e\\u003cstrong\\u003eSamples and m\\u003c/strong\\u003e\\u003cstrong\\u003eeasurements\\u003c/strong\\u003e\\u003c/h2\\u003e\\n\\u003ch3\\u003e\\u003cstrong\\u003eNutrient levels and growth performance\\u003c/strong\\u003e\\u003c/h3\\u003e\\n\\u003cp\\u003eDiet samples were collected daily during 19\\u0026ndash;45 d and stored at \\u0026minus;20\\u0026deg;C. At the end of the feeding experiment, dietary samples were composited and dried at 65\\u0026deg;C and were ground to pass a 1-mm screen for proximate chemical composition determination of DM, crude protein (CP), organic matter (OM), Ca and P [30]; and neutral detergent fiber (NDF) and acid detergent fiber (ADF) [31]. An atomic absorption spectrophotometer (iCE 3000 SERIES, Thermo Fisher Scientific, USA) was used to measure Na and K contents. Silver nitrate titration was used to determine Cl concentration. The S level was determined using the magnesium nitrate method as described by Wang and Beede [32]. The DCAD was calculated using the following equation:\\u003c/p\\u003e\\n\\u003cp\\u003eDCAD = Na (%)/0.0023 + K (%)/0.0039 \\u0026minus; Cl (%)/0.00355 \\u0026minus; S (%)/0.0016\\u003c/p\\u003e\\n\\u003cp\\u003eAll goats were weighed on d 32 as the initial weight and on 46 d as the final weight. The DMI was recorded daily for each goat calculated by allowance of refusals. The average net gain (ANG) was determined by subtraction of initial weight from final weight. The average daily gain (ADG) was determined by dividing ANG with the trial period (15 d). The feed conversion ratio (FCR) was the ratio of DMI to ADG. Total feces was collected during the last five consecutive days for nutrients digestibility analysis. Feces samples from individual goats were dried in an oven at 65\\u0026deg;C for 48 h and ground to pass a 1-mm screen for approximate nutrient measurements: CP and OM [30] and NDF and ADF [31].\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eRumen status\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eAt 9:00, 13:00, and 17:00 on d 44, rumen fluid was collected through the esophageal cannula via a vacuum pump (VP30, Labtech Instrument Co. Ltd, Beijing, China) and was measured pH using a pH meter (PHS-3C, Youke Instrument Co. Ltd, Shanghai, China). Sample collected at 17:00 was used to assess rumen buffering capability (BC) as described by Tucker et al. [33], and the operational procedure was titrating a 10-mL aliquot of the sample from the original pH dropping to pH 5 using 1 N HCl.\\u003c/p\\u003e\\n\\u003cp\\u003eRumen fluid (20 mL) was used to detect volatile fatty acids (VFA), and the remaining sample was used for microbial high-throughput sequencing analysis. To determine the VFA, acidified samples were centrifuged at 4\\u0026deg;C for 10 min (Thermo Fisher-ST 16R), and the supernatant fraction filtered through a 0.45-\\u0026micro;m filter. The 1280 \\u0026mu;L of filtrate was mixed with 600 \\u0026mu;L of 20% metaphosphoric acid and 120 \\u0026mu;L of crotonic acid (internal standard). The VFA concentrations in filtered samples were determined by gas chromatography (GC-2010-plus, Shimadzu, Japan) equipped with a flame ionization detector and a capillary column (SH-Rtx-Wax, Shimadzu), and nitrogen was used as the carrier gas. Rumen microbial high-throughput sequencing analysis was performed by TinyGen Bio-Tech (Shanghai) Co. Ltd.\\u003c/p\\u003e\\n\\u003ch3\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/h3\\u003e\\n\\u003ch3\\u003e\\u003cstrong\\u003ePCR amplification of 16S rRNA genes and Miseq sequencing\\u003c/strong\\u003e\\u003c/h3\\u003e\\n\\u003cp\\u003eRuminal fluid samples were stored at \\u0026minus;80\\u0026deg;C and the DNA extracted from 200-mg samples using a QIAamp DNA Stool Mini Kit (Qiagen, Hilden, Germany) following the manufacturer\\u0026rsquo;s instructions. The DNA concentration and purity were checked by running samples on 1.0% agarose gels.\\u003c/p\\u003e\\n\\u003cp\\u003eThe PCR amplification of 16S rRNA genes was performed using general bacterial primers: 515F 5ʹ-GTGCCAGCMGCCGCGGTAA-3ʹ and 926R 5ʹ-CCGTCAATTCMTTTGAGTTT-3ʹ. The primers also contained the Illumina 5ʹ-overhang adapter sequences for two-step amplicon library building, following the manufacturer\\u0026rsquo;s instructions for the overhang sequences. The initial PCR reactions were carried out in 25-\\u0026micro;L reaction volumes with 1\\u0026ndash;2 \\u0026micro;L of DNA template, 250 mM dNTPs, 0.25 mM of each primer, 1\\u0026times; reaction buffer, and 0.5 U of Phusion DNA Polymerase (New England Biolabs, USA). The PCR conditions consisted of initial denaturation at 94\\u0026deg;C for 2 min, followed by 25 cycles of denaturation at 94\\u0026deg;C for 30 s, annealing at 56\\u0026deg;C for 30 s, and extension at 72\\u0026deg;C for 30 s, with a final extension of 72\\u0026deg;C for 5 min. The second step of PCR with dual eight-base barcodes was used for multiplexing. Eight-cycle PCR reactions were used to incorporate two unique barcodes to either end of the 16S amplicons. Cycling conditions consisted of one cycle of 94\\u0026deg;C for 3 min, followed by eight cycles of 94\\u0026deg;C for 30 s, 56\\u0026deg;C for 30 s, and 72\\u0026deg;C for 30 s, and a final extension of 72\\u0026deg;C for 5 min. Prior to library pooling, the barcoded PCR products were purified using a DNA gel extraction kit (Axygen, China) and quantified using FTC-3000 TM real-time PCR. The libraries were sequenced by 2 \\u0026times; 300 bp paired-end sequencing on the MiSeq platform using MiSeq v3 Reagent Kit (Illumina) at Tiny Gene Bio-Tech (Shanghai) Co. Ltd.\\u003c/p\\u003e\\n\\u003ch3\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/h3\\u003e\\n\\u003ch3\\u003e\\u003cstrong\\u003eBioinformatic analysis\\u003c/strong\\u003e\\u003c/h3\\u003e\\n\\u003cp\\u003eThe raw fastq files were demultiplexed based on the barcode. The PE reads for all samples were run through Trimmomatic (version 0.35) to remove low-quality base pairs using parameters SLIDINGWINDOW: 50:20 and MINLEN: 50. Trimmed reads were then further merged using the FLASH program (version 1.2.11) with default parameters. The low-quality contigs were removed based on screen.seqs command using the following filtering parameters, maxambig = 0, minlength = 200, maxlength = 580, and maxhomop = 8. The 16S sequences were analyzed using a combination of software mothur (version 1.33.3), UPARSE (usearch version v8.1.1756, http://drive5.com/uparse/), and R (version 3.2.3). The demultiplexed reads were clustered at 97% sequence identity into operational taxonomic units (OTUs) using the UPARSE pipeline (\\u003ca href=\\\"http://drive5.com/usearch/manual/uparse%20cmds.html\\\"\\u003ehttp://drive5.com/usearch/manual/uparse cmds.html\\u003c/a\\u003e). The OTU representative sequences were used for taxonomic assignment against the Silva 128 database with a confidence score \\u0026ge;0.6 by the classify.seqs command in mothur. The OTU taxonomies (from phylum to species) were determined based on NCBI. The four members of the rumen cellulolytic bacteria community (\\u003cem\\u003eB. fibrisolvens\\u003c/em\\u003e,\\u003cem\\u003e F. succinogenes\\u003c/em\\u003e,\\u003cem\\u003e R. flavefaciens\\u003c/em\\u003e, and\\u003cem\\u003e R. albus\\u003c/em\\u003e, % of total bacterial 16S rDNA) were selected from \\u0026ldquo;Species\\u0026rdquo; for statistical analysis.\\u003c/p\\u003e\\n\\u003ch3\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/h3\\u003e\\n\\u003ch3\\u003e\\u003cstrong\\u003eUrine pH\\u003c/strong\\u003e\\u003c/h3\\u003e\\n\\u003cp\\u003eFor precise observation of the effect of DCAD level on acid\\u0026ndash;base balance \\u003cem\\u003ein vivo\\u003c/em\\u003e, urine pH was measured once every 3 d during the first and second adaption periods (1\\u0026ndash;12 and 13\\u0026ndash;18 d), once every 2 days during the third stage (19\\u0026ndash;30 d), and daily for the trial period (31\\u0026ndash;45 d). Urine was immediately dipped with special indicator paper (5.4\\u0026ndash;7.0, SSSreagent Co. Ltd, Shanghai, China; 6.4\\u0026ndash;9.0, Fuyang Special Paper Co. Ltd, Hangzhou, China) when goats urinated.\\u003c/p\\u003e\\n\\u003ch3\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/h3\\u003e\\n\\u003ch3\\u003e\\u003cstrong\\u003ePlasma \\u003c/strong\\u003e\\u003cstrong\\u003emetabolites\\u003c/strong\\u003e\\u003c/h3\\u003e\\n\\u003cp\\u003eBlood samples (10-mL) of every goat were collected from the jugular vein into heparinized plastic syringes at 45 d. Samples were centrifuged at 805\\u0026times;g for 15 min to harvest plasma. Plasma was subsequently analyzed for levels of Ca, glucose (Glu), urea nitrogen (UN), alanine aminotransferase (ALT), aspartate transaminase (AST), alkaline phosphatase (AKP), total protein (TP), albumin (Alb), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), and catalase (CAT).\\u003c/p\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003ch2\\u003e\\u003cstrong\\u003eStatistical analysis\\u003c/strong\\u003e\\u003c/h2\\u003e\\n\\u003cp\\u003eThe MIXED module in SAS 9.4 (SAS Institute Inc, Cary, NC, USA) was applied for analysis of experimental data. The DCAD levels (+338, +152, and \\u0026minus;181) were designated as fixed effects, and goats as the random effect, then Tukey\\u0026rsquo;s method was adopted to determine differences among means of the three DCAD treatments. The experiment results were expressed as mean \\u0026plusmn; standard deviation. Statistical significance was defined as \\u003cem\\u003eP \\u003c/em\\u003e\\u0026lt; 0.05.\\u003c/p\\u003e\"},{\"header\":\" Results\",\"content\":\"\\u003ch2\\u003e\\u003cstrong\\u003eRumen fermentation\\u003c/strong\\u003e\\u003c/h2\\u003e\\n\\u003cp\\u003eThere were no significant differences in rumen pH for the same sampling intervals (0, 4, and 8 h; \\u003cem\\u003eP\\u003c/em\\u003e \\u0026gt; 0.05; Table 2) and all the collected mean among the HD, CON, and LD treatments (0, 4, and 8 h; \\u003cem\\u003eP\\u003c/em\\u003e \\u0026gt; 0.05). The variation of DCAD had no effect on ruminal BC and levels of acetic acid, propionic acid, butyric acid, total VFA (TVFA), and acetic acid/propionic acid (A/P) in the goats (\\u003cem\\u003eP\\u003c/em\\u003e \\u0026gt; 0.05).\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eTable 2 \\u003c/strong\\u003eEffect of dietary cation\\u0026ndash;anion difference on the rumen pH of goats\\u003c/p\\u003e\\n\\u003ctable width=\\\"612\\\"\\u003e\\n\\u003ctbody\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd colspan=\\\"2\\\" rowspan=\\\"2\\\" width=\\\"191\\\"\\u003e\\n\\u003cp\\u003eItems\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd colspan=\\\"3\\\" width=\\\"302\\\"\\u003e\\n\\u003cp\\u003eDCAD\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd rowspan=\\\"2\\\" width=\\\"54\\\"\\u003e\\n\\u003cp\\u003eSEM\\u003csup\\u003e1\\u003c/sup\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd rowspan=\\\"2\\\" width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eP\\u003c/em\\u003e-value\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"105\\\"\\u003e\\n\\u003cp\\u003eHD (+338)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003eCON +152)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003eLD (-181)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd colspan=\\\"2\\\" width=\\\"191\\\"\\u003e\\n\\u003cp\\u003epH\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"105\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"54\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003eSampling time interval (h)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"78\\\"\\u003e\\n\\u003cp\\u003eSampling time\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"105\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"54\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e0\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"78\\\"\\u003e\\n\\u003cp\\u003e09:00\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"105\\\"\\u003e\\n\\u003cp\\u003e7.22 \\u0026plusmn; 0.19\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003e7.21 \\u0026plusmn; 0.41\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e7.17 \\u0026plusmn; 0.36\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"54\\\"\\u003e\\n\\u003cp\\u003e0.14\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.97\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"78\\\"\\u003e\\n\\u003cp\\u003e13:00\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"105\\\"\\u003e\\n\\u003cp\\u003e7.10 \\u0026plusmn; 0.22\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003e7.17 \\u0026plusmn; 0.57\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e6.99 \\u0026plusmn; 0.49\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"54\\\"\\u003e\\n\\u003cp\\u003e0.23\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.86\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"78\\\"\\u003e\\n\\u003cp\\u003e17:00\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"105\\\"\\u003e\\n\\u003cp\\u003e7.07 \\u0026plusmn; 0.25\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003e7.20 \\u0026plusmn; 0.66\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e6.98 \\u0026plusmn; 0.54\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"54\\\"\\u003e\\n\\u003cp\\u003e0.26\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.83\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e4\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"78\\\"\\u003e\\n\\u003cp\\u003e13:00\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"105\\\"\\u003e\\n\\u003cp\\u003e7.05 \\u0026plusmn; 0.31\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003e6.96 \\u0026plusmn; 0.36\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e7.04 \\u0026plusmn; 0.34\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"54\\\"\\u003e\\n\\u003cp\\u003e0.18\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.93\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"78\\\"\\u003e\\n\\u003cp\\u003e17:00\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"105\\\"\\u003e\\n\\u003cp\\u003e7.08 \\u0026plusmn; 0.38\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003e6.96 \\u0026plusmn; 0.52\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e7.14 \\u0026plusmn; 0.47\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"54\\\"\\u003e\\n\\u003cp\\u003e0.24\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.87\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"114\\\"\\u003e\\n\\u003cp\\u003e8\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"78\\\"\\u003e\\n\\u003cp\\u003e17:00\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"105\\\"\\u003e\\n\\u003cp\\u003e7.15 \\u0026plusmn; 0.23\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003e6.99 \\u0026plusmn; 0.38\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e7.08 \\u0026plusmn; 0.46\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"54\\\"\\u003e\\n\\u003cp\\u003e0.19\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.86\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd colspan=\\\"2\\\" width=\\\"191\\\"\\u003e\\n\\u003cp\\u003eMean\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"105\\\"\\u003e\\n\\u003cp\\u003e7.20 \\u0026plusmn; 0.22\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003e7.18 \\u0026plusmn; 0.41\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e7.17 \\u0026plusmn; 0.34\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"54\\\"\\u003e\\n\\u003cp\\u003e0.14\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.98\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd colspan=\\\"2\\\" width=\\\"191\\\"\\u003e\\n\\u003cp\\u003eBC\\u003csup\\u003e2 \\u003c/sup\\u003e(mL/L)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"105\\\"\\u003e\\n\\u003cp\\u003e44.75 \\u0026plusmn; 0.88\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003e43.35 \\u0026plusmn; 3.65\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e43.10 \\u0026plusmn; 3.81\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"54\\\"\\u003e\\n\\u003cp\\u003e1.38\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.67\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd colspan=\\\"2\\\" width=\\\"191\\\"\\u003e\\n\\u003cp\\u003eAcetic acid (mmol/L)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"105\\\"\\u003e\\n\\u003cp\\u003e42.22 \\u0026plusmn; 4.86\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003e43.45 \\u0026plusmn; 5.71\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e44.81 \\u0026plusmn; 6.36\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"54\\\"\\u003e\\n\\u003cp\\u003e2.32\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.74\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd colspan=\\\"2\\\" width=\\\"191\\\"\\u003e\\n\\u003cp\\u003ePropionic acid (mmol/L)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"105\\\"\\u003e\\n\\u003cp\\u003e13.00 \\u0026plusmn; 1.96\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003e13.07 \\u0026plusmn; 1.75\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e12.71 \\u0026plusmn; 2.37\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"54\\\"\\u003e\\n\\u003cp\\u003e0.84\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.95\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd colspan=\\\"2\\\" width=\\\"191\\\"\\u003e\\n\\u003cp\\u003eButyric acid (mmol/L)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"105\\\"\\u003e\\n\\u003cp\\u003e8.00 \\u0026plusmn; 1.78\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003e8.48 \\u0026plusmn; 2.28\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e8.11 \\u0026plusmn; 2.02\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"54\\\"\\u003e\\n\\u003cp\\u003e0.83\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.91\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd colspan=\\\"2\\\" width=\\\"191\\\"\\u003e\\n\\u003cp\\u003eTVFA\\u003csup\\u003e3\\u003c/sup\\u003e (mmol/L)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"105\\\"\\u003e\\n\\u003cp\\u003e63.21 \\u0026plusmn; 8.08\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003e65.01 \\u0026plusmn; 8.89\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e65.63 \\u0026plusmn; 8.10\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"54\\\"\\u003e\\n\\u003cp\\u003e3.41\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.87\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd colspan=\\\"2\\\" width=\\\"191\\\"\\u003e\\n\\u003cp\\u003eA/P\\u003csup\\u003e4\\u003c/sup\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"105\\\"\\u003e\\n\\u003cp\\u003e3.27 \\u0026plusmn; 0.34\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003e3.34 \\u0026plusmn; 0.36\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e3.67 \\u0026plusmn; 1.13\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"54\\\"\\u003e\\n\\u003cp\\u003e0.29\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.60\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003c/tbody\\u003e\\n\\u003c/table\\u003e\\n\\u003cp\\u003e\\u003csup\\u003e1\\u003c/sup\\u003eSEM=standard error of mean. The same as below.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003csup\\u003e2\\u003c/sup\\u003eBC=Buffering capability.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003csup\\u003e3\\u003c/sup\\u003eTVFA = acetic acid + propionic acid + butyric acid.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003csup\\u003e4\\u003c/sup\\u003eA/P = acetic acid/propionic acid.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eRumen cellulolytic bacteria\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThe relative contents of \\u003cem\\u003eF. succinogenes\\u003c/em\\u003e,\\u003cem\\u003e R. flavefaciens\\u003c/em\\u003e,\\u003cem\\u003e B. fibrisolvens\\u003c/em\\u003e,\\u003cem\\u003e and\\u003c/em\\u003e \\u003cem\\u003eR. albus \\u003c/em\\u003ewere not significantly affected among goats fed HD, CON, and LD diets (\\u003cem\\u003eP\\u003c/em\\u003e \\u0026gt; 0.05; Table 3). The proportions of \\u003cem\\u003eF. succinogenes\\u003c/em\\u003e and\\u003cem\\u003e R. flavefaciens \\u003c/em\\u003ewere markedly increased with lower DCAD compared to \\u003cem\\u003eB. fibrisolvens\\u003c/em\\u003e and \\u003cem\\u003eR. albus\\u003c/em\\u003e.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eTable 3 \\u003c/strong\\u003eEffect of dietary cation\\u0026ndash;anion difference on the rumen cellulolytic bacteria communities of goats\\u003c/p\\u003e\\n\\u003ctable width=\\\"640\\\"\\u003e\\n\\u003ctbody\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd rowspan=\\\"2\\\" width=\\\"218\\\"\\u003e\\n\\u003cp\\u003eItems\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd colspan=\\\"3\\\" width=\\\"298\\\"\\u003e\\n\\u003cp\\u003eDCAD\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd rowspan=\\\"2\\\" width=\\\"52\\\"\\u003e\\n\\u003cp\\u003eSEM\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd rowspan=\\\"2\\\" width=\\\"72\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eP\\u003c/em\\u003e-value\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003eHD (+338)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003eCON (+152)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003eLD (-181)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"218\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eFibrobacter succinogenes \\u003c/em\\u003e(%)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e0.443\\u0026plusmn;0.003\\u003c/p\\u003e\\n\\u003cp\\u003e(48.63 %)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003e0.362\\u0026plusmn;0.003\\u003c/p\\u003e\\n\\u003cp\\u003e(41.18 %)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e0.324\\u0026plusmn;0.001\\u003c/p\\u003e\\n\\u003cp\\u003e(62.91%)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"52\\\"\\u003e\\n\\u003cp\\u003e0.098\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"72\\\"\\u003e\\n\\u003cp\\u003e0.70\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"218\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eRuminococcus flavefaciens \\u003c/em\\u003e(%)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e0.343\\u0026plusmn;0.21\\u003c/p\\u003e\\n\\u003cp\\u003e(37.65 %)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003e0.414\\u0026plusmn;0.86\\u003c/p\\u003e\\n\\u003cp\\u003e(47.10 %)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e0.119\\u0026plusmn;0.09\\u003c/p\\u003e\\n\\u003cp\\u003e(23.11 %)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"52\\\"\\u003e\\n\\u003cp\\u003e0.210\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"72\\\"\\u003e\\n\\u003cp\\u003e0.51\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"218\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eButyrivibrio fibrisolvens \\u003c/em\\u003e(%)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e0.12\\u0026plusmn;0.12\\u003c/p\\u003e\\n\\u003cp\\u003e(13.17 %)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003e0.085\\u0026plusmn;0.07\\u003c/p\\u003e\\n\\u003cp\\u003e(9.67 %)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e0.065\\u0026plusmn;0.03\\u003c/p\\u003e\\n\\u003cp\\u003e(12.62 %)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"52\\\"\\u003e\\n\\u003cp\\u003e0.033\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"72\\\"\\u003e\\n\\u003cp\\u003e0.59\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"218\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eRuminococcus albus \\u003c/em\\u003e(%)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e0.005\\u0026plusmn;0.01\\u003c/p\\u003e\\n\\u003cp\\u003e(0.55 %)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"96\\\"\\u003e\\n\\u003cp\\u003e0.018\\u0026plusmn;0.03\\u003c/p\\u003e\\n\\u003cp\\u003e(2.05 %)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e0.007\\u0026plusmn;0.01\\u003c/p\\u003e\\n\\u003cp\\u003e(1.36 %)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"52\\\"\\u003e\\n\\u003cp\\u003e0.008\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"72\\\"\\u003e\\n\\u003cp\\u003e0.50\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003c/tbody\\u003e\\n\\u003c/table\\u003e\\n\\u003ch2\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/h2\\u003e\\n\\u003ch2\\u003e\\u003cstrong\\u003eSequencing and diversity of ruminal microbiota \\u003c/strong\\u003e\\u003c/h2\\u003e\\n\\u003cp\\u003eAfter Illumina Miseq high-throughput sequencing, a total of 698,626 valid reads were obtained with an average length of 410 bp. The VENN graph showed that there were 1075 of total 1261 OTU in 3 groups shared. There were 22, 25, 5 individual OTUs, accounting for 1.89%, 2.33%, and 0.43% for LD, HD, CON, respectively (Fig. 1). Rarefaction curves were established to quantify the OUT coverage of sampling and each rarefaction tended to be gentle with the increase of sequence number, and meanwhile, the OTU rank abundance in the 3 groups exhibited a gentler slope and wider distribution on the horizontal axis (Fig. 2).\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eFig. \\u003c/strong\\u003e\\u003cstrong\\u003e1\\u003c/strong\\u003e The VENN graph of rumen bacterial of goats fed diets with varying cation-anion difference levels, which displaying that the disposition of operational taxonomic units (OTUs) among the control group (CON, n=6), high dietary cation-anion difference (HD, n=6) and low dietary cation-anion difference (LD, n=6) in rumen fluid microbiota.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eFig. \\u003c/strong\\u003e\\u003cstrong\\u003e2\\u003c/strong\\u003e Rarefaction curves (A) and the OTU rank abundance (B) of rumen bacterial of goats fed diets with varying cation-anion difference levels. The CON group: CON1, CON2, CON3, CON4, CON5, CON6. The HD group: HD1, HD2, HD3, HD4, HD5, HD6. The LD group: LD1, LD2, LD3, LD4, LD5, LD6.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003eAlpha diversity results showed that DCAD levels did not affect Chao, Ace, Simpson, and Shannon as listed in Table 4 (\\u003cem\\u003eP \\u003c/em\\u003e\\u0026gt; 0.05). The Chao, Ace, Shanno and Simpson chart of each group was also tended to be gentle corresponding to the increase of sequence number (Fig. 3).\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eTable \\u003c/strong\\u003e\\u003cstrong\\u003e4 \\u003c/strong\\u003eEffect of varying dietary cation-anion difference levels on rumen bacterial community richness and diversity of goats\\u003c/p\\u003e\\n\\u003ctable width=\\\"600\\\"\\u003e\\n\\u003ctbody\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd colspan=\\\"2\\\" rowspan=\\\"2\\\" width=\\\"168\\\"\\u003e\\n\\u003cp\\u003eItems\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd colspan=\\\"3\\\" width=\\\"302\\\"\\u003e\\n\\u003cp\\u003eDietary treatments\\u003csup\\u003e1\\u003c/sup\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd rowspan=\\\"2\\\" width=\\\"54\\\"\\u003e\\n\\u003cp\\u003eSEM\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd rowspan=\\\"2\\\" width=\\\"75\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eP\\u003c/em\\u003e-value\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"100\\\"\\u003e\\n\\u003cp\\u003eHD (+338)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003eCON (+152)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"102\\\"\\u003e\\n\\u003cp\\u003eLD (\\u0026minus;181)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd rowspan=\\\"2\\\" width=\\\"87\\\"\\u003e\\n\\u003cp\\u003eBacterial Richness\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"81\\\"\\u003e\\n\\u003cp\\u003eChao\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"100\\\"\\u003e\\n\\u003cp\\u003e906\\u0026plusmn;89\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e843\\u0026plusmn;129\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"102\\\"\\u003e\\n\\u003cp\\u003e811\\u0026plusmn;116\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"54\\\"\\u003e\\n\\u003cp\\u003e4.28\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"75\\\"\\u003e\\n\\u003cp\\u003e0.333\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"81\\\"\\u003e\\n\\u003cp\\u003eAce\\u003csup\\u003e2\\u003c/sup\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"100\\\"\\u003e\\n\\u003cp\\u003e900\\u0026plusmn;82\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e834\\u0026plusmn;117\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"102\\\"\\u003e\\n\\u003cp\\u003e815\\u0026plusmn;96\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"54\\\"\\u003e\\n\\u003cp\\u003e4.33\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"75\\\"\\u003e\\n\\u003cp\\u003e0.356\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd rowspan=\\\"2\\\" width=\\\"87\\\"\\u003e\\n\\u003cp\\u003eBacterial Diversity\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"81\\\"\\u003e\\n\\u003cp\\u003eSimpson\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"100\\\"\\u003e\\n\\u003cp\\u003e0.027\\u0026plusmn;0.02\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e0.033\\u0026plusmn;0.01\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"102\\\"\\u003e\\n\\u003cp\\u003e0.028\\u0026plusmn;0.01\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"54\\\"\\u003e\\n\\u003cp\\u003e0.04\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"75\\\"\\u003e\\n\\u003cp\\u003e0.760\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"81\\\"\\u003e\\n\\u003cp\\u003eShannon\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"100\\\"\\u003e\\n\\u003cp\\u003e4.87\\u0026plusmn;0.31\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"101\\\"\\u003e\\n\\u003cp\\u003e4.45\\u0026plusmn;0.21\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"102\\\"\\u003e\\n\\u003cp\\u003e4.69\\u0026plusmn;0.29\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"54\\\"\\u003e\\n\\u003cp\\u003e0.21\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"75\\\"\\u003e\\n\\u003cp\\u003e0.048\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003c/tbody\\u003e\\n\\u003c/table\\u003e\\n\\u003cp\\u003e\\u003csup\\u003e1\\u003c/sup\\u003eDietary treatments: HD: High dietary cation-anion difference; CON:Control group; LD: Low dietary cation-anion difference.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003csup\\u003e2\\u003c/sup\\u003eAce=abundance-based coverage estimator.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eFig. \\u003c/strong\\u003e\\u003cstrong\\u003e3\\u003c/strong\\u003e Rarefaction curves (A) and the OTU rank abundance (B) of rumen bacterial of goats fed diets with varying cation-anion difference levels. The CON group: CON1, CON2, CON3, CON4, CON5, CON6. The HD group: HD1, HD2, HD3, HD4, HD5, HD6. The LD group: LD1, LD2, LD3, LD4, LD5, LD6.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003eAccording to Fig. 4, both weighted UniFrac (axis 1 + axis 2 = 66.7%, Fig. 4a) and unweighted UniFrac (axis 1 + axis 2 = 38.37%, Fig. 4b) were observed no difference in the composition of rumen microbiota for CON, HD and LD (\\u003cem\\u003eP \\u003c/em\\u003e\\u0026gt; 0.05).\\u003c/p\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003ctable\\u003e\\n\\u003ctbody\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"369\\\"\\u003e\\u0026nbsp;\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd\\u003e\\u0026nbsp;\\u003c/td\\u003e\\n\\u003ctd\\u003e\\u0026nbsp;\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003c/tbody\\u003e\\n\\u003c/table\\u003e\\n\\u003cp\\u003e\\u003cbr /\\u003e \\u003cstrong\\u003eFig. \\u003c/strong\\u003e\\u003cstrong\\u003e4\\u003c/strong\\u003e Principle coordinate analysis (PCoA) based on weighted UniFrac and unweighted UniFrac on rumen bacterial of goats fed diets with varying cation-anion difference levels. (a) PCoA based on weighted UniFrac of rumen bacterial of goats fed diets with varying cation-anion difference levels. (b) PCoA based on unweighted UniFrac of rumen bacterial of goats fed diets with varying dietary cation-anion difference levels. The percentage of variation explained by PC1 (first principal component) and PC2 (second principal component) was indicated in the axis. CON = the control group (n = 6); HD= high dietary cation-anion difference (n = 6); LD = low dietary cation-anion difference (n = 6).\\u003c/p\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003eTaxonomic classification summary indicated that 16 phyla were tested in all samples (Fig. 5A). At the phylum level, Bacteroidetes (61.60%) was the predominant phylum followed by Firmicutes, Synergistetes, Proteobacteria, Spirochaetae, Tenericutes with average relative abundances of 25.32%, 5.84%, 1.82%, 2.08%, 1.2%, respectively, but there was no difference (\\u003cem\\u003eP \\u003c/em\\u003e\\u0026gt; 0.05) among the groups on the above phylum levels except for Firmicutes, which was significantly higher in HD and LD compared to CON (\\u003cem\\u003eP\\u003c/em\\u003e=0.008, Table 5).\\u003c/p\\u003e\\n\\u003cp\\u003eAt the genus level, taxon displayed that the relative abundance of 11 genera were not affected by DCAD among all samples (\\u003cem\\u003eP \\u003c/em\\u003e\\u0026gt; 0.05; Fig. 5B). At the same time, \\u003cem\\u003ePrevotella, Paraprevotella, Selenomonas, Ruminococcus, Ruminococcus, Butyrivibrio, Quinella, Fretibacterium and Treponema \\u003c/em\\u003eshowed no grouping difference of the genera across treatments (\\u003cem\\u003eP \\u003c/em\\u003e\\u0026gt; 0.05). Among the genera with relative abundance exceeded 0.1%, prevotella was the dominant genus in each group with the highest proportion (Table 5).\\u003c/p\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eFig. \\u003c/strong\\u003e\\u003cstrong\\u003e5 \\u003c/strong\\u003eDistributions of microbiota at phyla and genus level. (a) Relative abundances of phyla levels are depicted as mean values for the CON, the LD (Low dietary cation-anion difference) group and HD (High dietary cation-anion difference) group. (b) Distributions of genera in rumen fluid of the CON, the LD (Low dietary cation-anion difference) group and HD (High dietary cation-anion difference) group.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eTable \\u003c/strong\\u003e\\u003cstrong\\u003e5 \\u003c/strong\\u003eEffect of varying dietary cation-cation difference on relative abundance (%) of bacteria taxa \\u0026gt; 0.1% of average abundance in the rumen fluid of goats\\u003c/p\\u003e\\n\\u003ctable width=\\\"655\\\"\\u003e\\n\\u003ctbody\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd rowspan=\\\"2\\\" width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003ePhylum\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd rowspan=\\\"2\\\" width=\\\"126\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003eGenus\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd colspan=\\\"3\\\" width=\\\"287\\\"\\u003e\\n\\u003cp\\u003eDietary treatments\\u003csup\\u003e1\\u003c/sup\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd rowspan=\\\"2\\\" width=\\\"52\\\"\\u003e\\n\\u003cp\\u003eSEM\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd rowspan=\\\"2\\\" width=\\\"70\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eP\\u003c/em\\u003e-value\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003eHD\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"93\\\"\\u003e\\n\\u003cp\\u003eCON\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003eLD\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eBacteroidetes\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"126\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026nbsp;\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e60.40\\u0026plusmn;6.24\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"93\\\"\\u003e\\n\\u003cp\\u003e65.08\\u0026plusmn;4.41\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e59.33\\u0026plusmn;9.13\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"52\\\"\\u003e\\n\\u003cp\\u003e2.81\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"70\\\"\\u003e\\n\\u003cp\\u003e0.328\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026nbsp;\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"126\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003ePrevotella\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e18.92\\u0026plusmn;3.66\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"93\\\"\\u003e\\n\\u003cp\\u003e24.16\\u0026plusmn;2.72\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e16.09\\u0026plusmn;2.68\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"52\\\"\\u003e\\n\\u003cp\\u003e3.05\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"70\\\"\\u003e\\n\\u003cp\\u003e0.223\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026nbsp;\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"126\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eParaprevotella\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e3.58\\u0026plusmn;1.23\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"93\\\"\\u003e\\n\\u003cp\\u003e2.76\\u0026plusmn;0.89\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e3.51\\u0026plusmn;1.52\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"52\\\"\\u003e\\n\\u003cp\\u003e1.24\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"70\\\"\\u003e\\n\\u003cp\\u003e0.877\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eFirmicutes\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"126\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026nbsp;\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e28.43\\u0026plusmn;4.90\\u003csup\\u003ea\\u003c/sup\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"93\\\"\\u003e\\n\\u003cp\\u003e18.71\\u0026plusmn;5.30\\u003csup\\u003eb\\u003c/sup\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e28.81\\u0026plusmn;6.08\\u003csup\\u003ea\\u003c/sup\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"52\\\"\\u003e\\n\\u003cp\\u003e2.23\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"70\\\"\\u003e\\n\\u003cp\\u003e0.008\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"126\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eSelenomonas\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e1.59\\u0026plusmn;0.97\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"93\\\"\\u003e\\n\\u003cp\\u003e0.56\\u0026plusmn;0.29\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e1.32\\u0026plusmn;0.89\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"52\\\"\\u003e\\n\\u003cp\\u003e0.78\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"70\\\"\\u003e\\n\\u003cp\\u003e0.629\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026nbsp;\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"126\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eRuminococcus\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e1.07\\u0026plusmn;0.16\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"93\\\"\\u003e\\n\\u003cp\\u003e1.54\\u0026plusmn;0.74\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e1.29\\u0026plusmn;0.39\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"52\\\"\\u003e\\n\\u003cp\\u003e0.49\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"70\\\"\\u003e\\n\\u003cp\\u003e0.786\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026nbsp;\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"126\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eSucciniclasticum\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e1.34\\u0026plusmn;0.36\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"93\\\"\\u003e\\n\\u003cp\\u003e0.69\\u0026plusmn;0.09\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e0.68\\u0026plusmn;0.24\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"52\\\"\\u003e\\n\\u003cp\\u003e0.25\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"70\\\"\\u003e\\n\\u003cp\\u003e0.143\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026nbsp;\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"126\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eButyrivibrio\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e1.02\\u0026plusmn;0.32\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"93\\\"\\u003e\\n\\u003cp\\u003e0.46\\u0026plusmn;0.13\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e0.48\\u0026plusmn;0.01\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"52\\\"\\u003e\\n\\u003cp\\u003e0.20\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"70\\\"\\u003e\\n\\u003cp\\u003e0.118\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026nbsp;\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"126\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eQuinella\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e2.29\\u0026plusmn;0.37\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"93\\\"\\u003e\\n\\u003cp\\u003e0.71\\u0026plusmn;0.30\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e3.73\\u0026plusmn;2.15\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"52\\\"\\u003e\\n\\u003cp\\u003e1.27\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"70\\\"\\u003e\\n\\u003cp\\u003e0.277\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eSynergistetes\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"126\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026nbsp;\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e5.20\\u0026plusmn;1.87\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"93\\\"\\u003e\\n\\u003cp\\u003e6.34\\u0026plusmn;1.91\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e5.99\\u0026plusmn;2.29\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"52\\\"\\u003e\\n\\u003cp\\u003e2.03\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"70\\\"\\u003e\\n\\u003cp\\u003e0.923\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026nbsp;\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"126\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eFretibacterium\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e5.18\\u0026plusmn;1.88\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"93\\\"\\u003e\\n\\u003cp\\u003e6.31\\u0026plusmn;1.92\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e5.97\\u0026plusmn;2.30\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"52\\\"\\u003e\\n\\u003cp\\u003e2.04\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"70\\\"\\u003e\\n\\u003cp\\u003e0.923\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eSpirochaetae\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"126\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026nbsp;\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e1.44\\u0026plusmn;0.25\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"93\\\"\\u003e\\n\\u003cp\\u003e2.13\\u0026plusmn;0.74\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e1.89\\u0026plusmn;0.35\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"52\\\"\\u003e\\n\\u003cp\\u003e0.49\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"70\\\"\\u003e\\n\\u003cp\\u003e0.610\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026nbsp;\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"126\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eTreponema\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e0.72\\u0026plusmn;0.16\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"93\\\"\\u003e\\n\\u003cp\\u003e0.98\\u0026plusmn;0.52\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e1.39\\u0026plusmn;0.35\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"52\\\"\\u003e\\n\\u003cp\\u003e0.37\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"70\\\"\\u003e\\n\\u003cp\\u003e0.458\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eProteobacteria\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"126\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026nbsp;\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e1.10\\u0026plusmn;0.42\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"93\\\"\\u003e\\n\\u003cp\\u003e4.49\\u0026plusmn;2.38\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e0.67\\u0026plusmn;0.07\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"52\\\"\\u003e\\n\\u003cp\\u003e1.40\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"70\\\"\\u003e\\n\\u003cp\\u003e0.140\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eTenericutes\\u003c/em\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"126\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e1.07\\u0026plusmn;0.17\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"93\\\"\\u003e\\n\\u003cp\\u003e1.20\\u0026plusmn;0.16\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"97\\\"\\u003e\\n\\u003cp\\u003e1.33\\u0026plusmn;0.44\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"52\\\"\\u003e\\n\\u003cp\\u003e0.29\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"70\\\"\\u003e\\n\\u003cp\\u003e0.817\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003c/tbody\\u003e\\n\\u003c/table\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003ch2\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/h2\\u003e\\n\\u003ch2\\u003e\\u003cstrong\\u003eGrowth performance\\u003c/strong\\u003e\\u003c/h2\\u003e\\n\\u003cp\\u003eLevels of DMI were unaffected by DCAD variations (P \\u0026gt; 0.05; Table 6). Lower DCAD had no effect (P \\u0026gt; 0.05) on gwowth performance of final weight, ANG, ADG, and FCR and digestibility of crude protein, NDF, ADF, and OM for goats.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eTable 6 \\u003c/strong\\u003eEffect of dietary cation\\u0026ndash;anion difference on growth performance of goats\\u003c/p\\u003e\\n\\u003ctable width=\\\"618\\\"\\u003e\\n\\u003ctbody\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd rowspan=\\\"2\\\" width=\\\"160\\\"\\u003e\\n\\u003cp\\u003eItems\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd colspan=\\\"3\\\" width=\\\"326\\\"\\u003e\\n\\u003cp\\u003eDCAD\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd rowspan=\\\"2\\\" width=\\\"60\\\"\\u003e\\n\\u003cp\\u003eSEM\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd rowspan=\\\"2\\\" width=\\\"71\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eP\\u003c/em\\u003e-value\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"112\\\"\\u003e\\n\\u003cp\\u003eHD (+338)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"104\\\"\\u003e\\n\\u003cp\\u003eCON (+152)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"111\\\"\\u003e\\n\\u003cp\\u003eLD (-181)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"160\\\"\\u003e\\n\\u003cp\\u003ePerformance\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"112\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"104\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"111\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"60\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"71\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"160\\\"\\u003e\\n\\u003cp\\u003eInitial weight (kg)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"112\\\"\\u003e\\n\\u003cp\\u003e30.35 \\u0026plusmn; 3.4\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"104\\\"\\u003e\\n\\u003cp\\u003e30.43 \\u0026plusmn; 2.6\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"111\\\"\\u003e\\n\\u003cp\\u003e29.44 \\u0026plusmn; 3.7\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"60\\\"\\u003e\\n\\u003cp\\u003e1.36\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"71\\\"\\u003e\\n\\u003cp\\u003e0.86\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"160\\\"\\u003e\\n\\u003cp\\u003eDMI (g/d)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"112\\\"\\u003e\\n\\u003cp\\u003e899.0 \\u0026plusmn; 213.6\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"104\\\"\\u003e\\n\\u003cp\\u003e857.5 \\u0026plusmn; 120.9\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"111\\\"\\u003e\\n\\u003cp\\u003e864.0 \\u0026plusmn; 124.3\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"60\\\"\\u003e\\n\\u003cp\\u003e64.85\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"71\\\"\\u003e\\n\\u003cp\\u003e0.89\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"160\\\"\\u003e\\n\\u003cp\\u003eFinal weight (kg)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"112\\\"\\u003e\\n\\u003cp\\u003e31.33 \\u0026plusmn; 3.4\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"104\\\"\\u003e\\n\\u003cp\\u003e31.50 \\u0026plusmn; 3.8\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"111\\\"\\u003e\\n\\u003cp\\u003e30.41 \\u0026plusmn; 3.3\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"60\\\"\\u003e\\n\\u003cp\\u003e1.48\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"71\\\"\\u003e\\n\\u003cp\\u003e0.82\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"160\\\"\\u003e\\n\\u003cp\\u003eANG (kg)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"112\\\"\\u003e\\n\\u003cp\\u003e0.98 \\u0026plusmn; 0.3\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"104\\\"\\u003e\\n\\u003cp\\u003e1.07 \\u0026plusmn; 0.4\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"111\\\"\\u003e\\n\\u003cp\\u003e0.97 \\u0026plusmn; 0.3\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"60\\\"\\u003e\\n\\u003cp\\u003e0.21\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"71\\\"\\u003e\\n\\u003cp\\u003e0.89\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"160\\\"\\u003e\\n\\u003cp\\u003eADG (g/d)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"112\\\"\\u003e\\n\\u003cp\\u003e65.3 \\u0026plusmn; 12.2\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"104\\\"\\u003e\\n\\u003cp\\u003e71.3 \\u0026plusmn; 22.7\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"111\\\"\\u003e\\n\\u003cp\\u003e64.7 \\u0026plusmn; 18.8\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"60\\\"\\u003e\\n\\u003cp\\u003e8.28\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"71\\\"\\u003e\\n\\u003cp\\u003e0.63\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"160\\\"\\u003e\\n\\u003cp\\u003eFCR\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"112\\\"\\u003e\\n\\u003cp\\u003e13.76 \\u0026plusmn; 6.6\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"104\\\"\\u003e\\n\\u003cp\\u003e12.02 \\u0026plusmn; 3.5\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"111\\\"\\u003e\\n\\u003cp\\u003e13.36 \\u0026plusmn; 5.9\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"60\\\"\\u003e\\n\\u003cp\\u003e3.00\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"71\\\"\\u003e\\n\\u003cp\\u003e0.81\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"160\\\"\\u003e\\n\\u003cp\\u003eDigestibility (%)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"112\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"104\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"111\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"60\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"71\\\"\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"160\\\"\\u003e\\n\\u003cp\\u003eCP (%)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"112\\\"\\u003e\\n\\u003cp\\u003e56.37 \\u0026plusmn; 2.41\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"104\\\"\\u003e\\n\\u003cp\\u003e58.66 \\u0026plusmn; 5.91\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"111\\\"\\u003e\\n\\u003cp\\u003e57.68 \\u0026plusmn; 5.42\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"60\\\"\\u003e\\n\\u003cp\\u003e1.97\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"71\\\"\\u003e\\n\\u003cp\\u003e0.75\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"160\\\"\\u003e\\n\\u003cp\\u003eNDF (%)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"112\\\"\\u003e\\n\\u003cp\\u003e50.26 \\u0026plusmn; 6.01\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"104\\\"\\u003e\\n\\u003cp\\u003e45.84 \\u0026plusmn; 8.39\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"111\\\"\\u003e\\n\\u003cp\\u003e45.58 \\u0026plusmn; 7.65\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"60\\\"\\u003e\\n\\u003cp\\u003e3.12\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"71\\\"\\u003e\\n\\u003cp\\u003e0.50\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"160\\\"\\u003e\\n\\u003cp\\u003eADF (%)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"112\\\"\\u003e\\n\\u003cp\\u003e51.19 \\u0026plusmn; 6.84\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"104\\\"\\u003e\\n\\u003cp\\u003e48.35 \\u0026plusmn; 7.74\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"111\\\"\\u003e\\n\\u003cp\\u003e47.59 \\u0026plusmn; 8.27\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"60\\\"\\u003e\\n\\u003cp\\u003e3.20\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"71\\\"\\u003e\\n\\u003cp\\u003e0.71\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"160\\\"\\u003e\\n\\u003cp\\u003eOM (%)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"112\\\"\\u003e\\n\\u003cp\\u003e62.34 \\u0026plusmn; 3.59\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"104\\\"\\u003e\\n\\u003cp\\u003e57.73 \\u0026plusmn; 5.66\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"111\\\"\\u003e\\n\\u003cp\\u003e58.59 \\u0026plusmn; 3.92\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"60\\\"\\u003e\\n\\u003cp\\u003e2.11\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"71\\\"\\u003e\\n\\u003cp\\u003e0.36\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003c/tbody\\u003e\\n\\u003c/table\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003ch2\\u003e\\u003cstrong\\u003eUrine pH\\u003c/strong\\u003e\\u003c/h2\\u003e\\n\\u003cp\\u003eThere was no difference (\\u003cem\\u003eP\\u003c/em\\u003e \\u0026gt; 0.05) in urine pH for HD, CON, and LD during the observation period of 1\\u0026ndash;12 d, with pH values of 8.48, 8.43, and 8.46, respectively (Fig. 6a). Urine pH decreased slightly (8.45, 8.50, and 8.13 for HD, CON, and LD, respectively) during the dietary replacement period (13\\u0026ndash;18 d). Urine pH decreased significantly (8.43, 8.36, and 7.40 for HD, CON, and LD, respectively) with LD obviously lower than both HD and CON. During the trial period (31\\u0026ndash;45 d), compared with HD and CON, LD reduced urine pH over HD and CON (8.43, 8.42, and 6.75 for HD, CON, and LD, respectively; \\u003cem\\u003eP\\u003c/em\\u003e \\u0026lt; 0.05). Urine pH values were unaffected by DCAD variation between HD and CON (\\u003cem\\u003eP\\u003c/em\\u003e \\u0026gt; 0.05). Furthermore, urine pH was closely related to DCAD levels within the trial period (31\\u0026ndash;45 d; R\\u003csup\\u003e2 \\u003c/sup\\u003e= 0.9066, \\u003cem\\u003eP \\u0026lt; \\u003c/em\\u003e0.05; Fig. 6b).\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eFig. 6a \\u003c/strong\\u003eGoat urine pH for dietary cation\\u0026ndash;anion difference levels throughout the experiment\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eFig. 6b \\u003c/strong\\u003eAssociation between urine pH and dietary cation-anion difference of goats in the trial period\\u003c/p\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n\\u003ch2\\u003e\\u003cstrong\\u003ePlasma \\u003c/strong\\u003e\\u003cstrong\\u003eMetabolites\\u003c/strong\\u003e\\u003c/h2\\u003e\\n\\u003cp\\u003eFeeding of the LD diet resulted in the highest plasma Ca level (Table 7), which was significantly higher than both HD and CON (\\u003cem\\u003eP\\u003c/em\\u003e \\u0026lt; 0.05).There were no significant differences in plasma Glu, UN, ALT, AST, AKP, TP, Alb, GSH-Px, CAT, SOD, and MDA among the DCAD treatments (\\u003cem\\u003eP\\u003c/em\\u003e \\u0026gt; 0.05; Table 7).\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eTable 7 \\u003c/strong\\u003eEffect of dietary cation\\u0026ndash;anion difference on the plasma metabolites of goats\\u003c/p\\u003e\\n\\u003ctable width=\\\"633\\\"\\u003e\\n\\u003ctbody\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd rowspan=\\\"2\\\" width=\\\"146\\\"\\u003e\\n\\u003cp\\u003eItems\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd colspan=\\\"3\\\" width=\\\"358\\\"\\u003e\\n\\u003cp\\u003eDCAD\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd rowspan=\\\"2\\\" width=\\\"63\\\"\\u003e\\n\\u003cp\\u003eSEM\\u003csup\\u003e1\\u003c/sup\\u003e\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd rowspan=\\\"2\\\" width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eP\\u003c/em\\u003e-value\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"120\\\"\\u003e\\n\\u003cp\\u003eHD (+338)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"115\\\"\\u003e\\n\\u003cp\\u003eCON (+152)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003eLD (\\u0026minus;181)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"146\\\"\\u003e\\n\\u003cp\\u003eCa (mmol/L)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"120\\\"\\u003e\\n\\u003cp\\u003e2.31 \\u0026plusmn; 0.21\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"115\\\"\\u003e\\n\\u003cp\\u003e2.38 \\u0026plusmn; 0.17\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e2.91 \\u0026plusmn; 0.17\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"63\\\"\\u003e\\n\\u003cp\\u003e0.08\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e\\u0026lt;0.01\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"146\\\"\\u003e\\n\\u003cp\\u003eGlu (mmol/L)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"120\\\"\\u003e\\n\\u003cp\\u003e4.57 \\u0026plusmn; 1.06\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"115\\\"\\u003e\\n\\u003cp\\u003e5.07 \\u0026plusmn; 0.91\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e4.60 \\u0026plusmn; 0.36\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"63\\\"\\u003e\\n\\u003cp\\u003e0.34\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.56\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"146\\\"\\u003e\\n\\u003cp\\u003eUN (mmol/L)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"120\\\"\\u003e\\n\\u003cp\\u003e6.22 \\u0026plusmn; 0.66\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"115\\\"\\u003e\\n\\u003cp\\u003e5.63 \\u0026plusmn; 1.09\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e6.24 \\u0026plusmn; 1.16\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"63\\\"\\u003e\\n\\u003cp\\u003e0.41\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.50\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"146\\\"\\u003e\\n\\u003cp\\u003eALT (IU/L)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"120\\\"\\u003e\\n\\u003cp\\u003e8.61 \\u0026plusmn; 2.55\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"115\\\"\\u003e\\n\\u003cp\\u003e10.22 \\u0026plusmn; 3.21\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e10.76 \\u0026plusmn; 3.57\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"63\\\"\\u003e\\n\\u003cp\\u003e1.70\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.85\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"146\\\"\\u003e\\n\\u003cp\\u003eAST (IU/L)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"120\\\"\\u003e\\n\\u003cp\\u003e11.25 \\u0026plusmn; 3.63\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"115\\\"\\u003e\\n\\u003cp\\u003e13.98 \\u0026plusmn; 4.77\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e11.91 \\u0026plusmn; 3.41\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"63\\\"\\u003e\\n\\u003cp\\u003e2.01\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.80\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"146\\\"\\u003e\\n\\u003cp\\u003eAKP\\u003c/p\\u003e\\n\\u003cp\\u003e(King unit/100 mL)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"120\\\"\\u003e\\n\\u003cp\\u003e20.85 \\u0026plusmn; 6.90\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"115\\\"\\u003e\\n\\u003cp\\u003e21.73 \\u0026plusmn; 12.57\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e17.81 \\u0026plusmn; 6.92\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"63\\\"\\u003e\\n\\u003cp\\u003e3.75\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.75\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"146\\\"\\u003e\\n\\u003cp\\u003eTP (g/L)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"120\\\"\\u003e\\n\\u003cp\\u003e99.38 \\u0026plusmn; 14.10\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"115\\\"\\u003e\\n\\u003cp\\u003e112.89 \\u0026plusmn; 28.72\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e92.62 \\u0026plusmn; 21.62\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"63\\\"\\u003e\\n\\u003cp\\u003e11.47\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.37\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"146\\\"\\u003e\\n\\u003cp\\u003eAlb (g/L)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"120\\\"\\u003e\\n\\u003cp\\u003e36.38 \\u0026plusmn; 4.34\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"115\\\"\\u003e\\n\\u003cp\\u003e37.11 \\u0026plusmn; 6.36\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e35.19 \\u0026plusmn; 6.31\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"63\\\"\\u003e\\n\\u003cp\\u003e2.35\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.85\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"146\\\"\\u003e\\n\\u003cp\\u003eGSH-Px (U/mL)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"120\\\"\\u003e\\n\\u003cp\\u003e670.59 \\u0026plusmn; 127.49\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"115\\\"\\u003e\\n\\u003cp\\u003e755.29\\u0026plusmn;296.72\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e709.41 \\u0026plusmn; 164.46\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"63\\\"\\u003e\\n\\u003cp\\u003e152.50\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.59\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"146\\\"\\u003e\\n\\u003cp\\u003eCAT (U/mL)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"120\\\"\\u003e\\n\\u003cp\\u003e2.35 \\u0026plusmn; 0.79\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"115\\\"\\u003e\\n\\u003cp\\u003e1.95 \\u0026plusmn; 0.60\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e2.47 \\u0026plusmn; 1.03\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"63\\\"\\u003e\\n\\u003cp\\u003e0.66\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.84\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"146\\\"\\u003e\\n\\u003cp\\u003eSOD (U/mL)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"120\\\"\\u003e\\n\\u003cp\\u003e68.53 \\u0026plusmn; 9.27\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"115\\\"\\u003e\\n\\u003cp\\u003e63.59 \\u0026plusmn; 8.59\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e67.98 \\u0026plusmn; 6.79\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"63\\\"\\u003e\\n\\u003cp\\u003e3.38\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.43\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003ctr\\u003e\\n\\u003ctd width=\\\"146\\\"\\u003e\\n\\u003cp\\u003eMDA (nmol/mL)\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"120\\\"\\u003e\\n\\u003cp\\u003e37.14 \\u0026plusmn; 5.57\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"115\\\"\\u003e\\n\\u003cp\\u003e34.61 \\u0026plusmn; 7.06\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"122\\\"\\u003e\\n\\u003cp\\u003e36.79 \\u0026plusmn; 5.94\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"63\\\"\\u003e\\n\\u003cp\\u003e2.54\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003ctd width=\\\"65\\\"\\u003e\\n\\u003cp\\u003e0.75\\u003c/p\\u003e\\n\\u003c/td\\u003e\\n\\u003c/tr\\u003e\\n\\u003c/tbody\\u003e\\n\\u003c/table\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\"},{\"header\":\" Discussion\",\"content\":\" \\u003cp\\u003eRumen pH has a key role in measuring rumen status and can reflect the composition and abundance of rumen microflora. Rumen health is maintained by an appropriate pH which is in range of 6.26\\u0026thinsp;~\\u0026thinsp;6.79 [\\u003cspan citationid=\\\"CR34\\\" class=\\\"CitationRef\\\"\\u003e34\\u003c/span\\u003e]. Rumen pH decreases when ruminants are fed high levels of concentrate. This is quite different from the acidified rumen status induced by increases in anion (Cl\\u003csup\\u003e\\u0026minus;\\u003c/sup\\u003e and S\\u003csup\\u003e2\\u0026minus;\\u003c/sup\\u003e) concentrations in the diet and which elevates Cl\\u003csup\\u003e\\u0026minus;\\u003c/sup\\u003e and S\\u003csup\\u003e2\\u0026minus;\\u003c/sup\\u003e in the urine and so reduces urine pH. In this study, rumen pH was unaffected for all DCAD treatments and ruminal fluid sampling time points. This was also shown in the study of Apper-Bossard [\\u003cspan citationid=\\\"CR35\\\" class=\\\"CitationRef\\\"\\u003e35\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eBriggs et al. [\\u003cspan citationid=\\\"CR36\\\" class=\\\"CitationRef\\\"\\u003e36\\u003c/span\\u003e] found that rumen BC was closely related to rumen pH, and Church [\\u003cspan citationid=\\\"CR37\\\" class=\\\"CitationRef\\\"\\u003e37\\u003c/span\\u003e] argued that the rumen buffer system was controlled by pH, \\u003cem\\u003ep\\u003c/em\\u003eCO\\u003csub\\u003e2\\u003c/sub\\u003e, and VFA. The rumen BC can maintain a stable rumen status by keeping any sudden rise or fall in rumen pH within a certain range [\\u003cspan citationid=\\\"CR38\\\" class=\\\"CitationRef\\\"\\u003e38\\u003c/span\\u003e]. The rumen has a relatively stable buffer system, which is closely related to the feed, saliva, and secretion of the rumen wall and maintains the rumen internal environment. In our study, the lack of significant difference in rumen BC and pH showed that DCAD reduction did not influence the rumen internal environment. However, the rumen BC was numerically elevated with increased DCAD level on cows when adding NaHCO\\u003csub\\u003e3\\u003c/sub\\u003e [\\u003cspan citationid=\\\"CR33\\\" class=\\\"CitationRef\\\"\\u003e33\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR39\\\" class=\\\"CitationRef\\\"\\u003e39\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR40\\\" class=\\\"CitationRef\\\"\\u003e40\\u003c/span\\u003e]. The explanation could be attributed to the use of a different animal species and different dietary ingredients. Generally, up to now there has been insufficient information on rumen BC in goats, and further study is needed due to the importance of BC for rumen status.\\u003c/p\\u003e \\u003cp\\u003eThe rumen VFA profile is mainly impacted by the proportion of concentrate and forage in the diet. Increasing DCAD, by adding K and Na, had no effect on rumen VFA concentration [\\u003cspan citationid=\\\"CR41\\\" class=\\\"CitationRef\\\"\\u003e41\\u003c/span\\u003e]. Tucker et al. [\\u003cspan citationid=\\\"CR42\\\" class=\\\"CitationRef\\\"\\u003e42\\u003c/span\\u003e] reported that the rumen VFA profile was unaffected by DCAD levels of \\u0026minus;\\u0026thinsp;100, 0, 100, and 200. Apper-Bossard et al. [\\u003cspan citationid=\\\"CR35\\\" class=\\\"CitationRef\\\"\\u003e35\\u003c/span\\u003e] found no significant difference in VFA concentration with varying DCAD. These results are consistent with the present study in which rumen VFA concentration was not significantly affected by DCAD level. Correspondingly, the VFA profiles and A/P levels were unaffected by DCAD. This indicates that the rumen fermentation pattern was unaltered by the three DCAD treatments.\\u003c/p\\u003e \\u003cp\\u003eIn the current study, DCAD variation had no influence on the populations of \\u003cem\\u003eB. fibrisolvens\\u003c/em\\u003e, \\u003cem\\u003eF. succinogenes\\u003c/em\\u003e, \\u003cem\\u003eR. flavefaciens\\u003c/em\\u003e, and \\u003cem\\u003eR. albus\\u003c/em\\u003e. This result indicates that reducing DCAD would not affect the growth and colonization of rumen cellulolytic bacteria. This is likely associated with stable rumen pH and VFA maintained by the constant ratio of concentrate to roughage (30:70) for the three DCAD diets used in this study. Grilli et al. [\\u003cspan citationid=\\\"CR43\\\" class=\\\"CitationRef\\\"\\u003e43\\u003c/span\\u003e] reported that a high proportion of maize disturbed the ruminal bacterial ecosystem of goats. Wang et al. [\\u003cspan citationid=\\\"CR44\\\" class=\\\"CitationRef\\\"\\u003e44\\u003c/span\\u003e] and Li et al. [\\u003cspan citationid=\\\"CR45\\\" class=\\\"CitationRef\\\"\\u003e45\\u003c/span\\u003e] noted that the relative quantity of ruminal \\u003cem\\u003eB. fibrisolvens\\u003c/em\\u003e, \\u003cem\\u003eF. succinogenes\\u003c/em\\u003e, \\u003cem\\u003eR. flavefaciens\\u003c/em\\u003e, and \\u003cem\\u003eR. albus\\u003c/em\\u003e was improved with decreasing rumen pH. In our most recent study (unpublished data) with dairy goats as experimental animals fed 4 DCAD levels at 349, 120, and \\u0026minus;\\u0026thinsp;167, respectively, rumen BC was not influenced. This result also supports the conclusions in the present study.\\u003c/p\\u003e \\u003cp\\u003eThe microbiota composition of the gastrointestinal tract (GIT) influence the health of animals as well as productivity [\\u003cspan citationid=\\\"CR46\\\" class=\\\"CitationRef\\\"\\u003e46\\u003c/span\\u003e], the structure and composition of ruminant microbial community are often devoted to evaluating the health status of the host and ensuring the healthy development of the rumen. Furthermore, the diversity and composition of the GIT microbiota can be influenced by many factors including age, diet, feeding management and feed additives [\\u003cspan citationid=\\\"CR47\\\" class=\\\"CitationRef\\\"\\u003e47\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR48\\\" class=\\\"CitationRef\\\"\\u003e48\\u003c/span\\u003e]. Microbial richness in rumen will be altered with dietary composition [\\u003cspan citationid=\\\"CR49\\\" class=\\\"CitationRef\\\"\\u003e49\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR50\\\" class=\\\"CitationRef\\\"\\u003e50\\u003c/span\\u003e]. Dietary nutrients are fermented by rumen rumen microbial, such as bacteria, fungi and protozoa, and then degraded into VFA and MCP to provide energy for ruminants [\\u003cspan citationid=\\\"CR51\\\" class=\\\"CitationRef\\\"\\u003e51\\u003c/span\\u003e] and to guarantee the healthy and stable rumen environment [\\u003cspan citationid=\\\"CR52\\\" class=\\\"CitationRef\\\"\\u003e52\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR53\\\" class=\\\"CitationRef\\\"\\u003e53\\u003c/span\\u003e]. In such reactions, rumen pH plays a decisive role in the composition and abundance of rumen microflora, and is an important indicator reflecting whether the composition and abundance of rumen microflora are normal [\\u003cspan citationid=\\\"CR54\\\" class=\\\"CitationRef\\\"\\u003e54\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR55\\\" class=\\\"CitationRef\\\"\\u003e55\\u003c/span\\u003e]. Similarly, rumen microbial is also influenced by animal species, diet composition and different ages [\\u003cspan additionalcitationids=\\\"CR57\\\" citationid=\\\"CR56\\\" class=\\\"CitationRef\\\"\\u003e56\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR58\\\" class=\\\"CitationRef\\\"\\u003e58\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eThe study of Zhang et al. [\\u003cspan citationid=\\\"CR59\\\" class=\\\"CitationRef\\\"\\u003e59\\u003c/span\\u003e] showed that rumen bacterial species, Chao index and Ace index were affected by rumen pH which can alter the bacterial community structure. Accordingly, Guo [\\u003cspan citationid=\\\"CR60\\\" class=\\\"CitationRef\\\"\\u003e60\\u003c/span\\u003e] found that decreased rumen pH would up-regulate bacterial diversity, composition and abundance of bacteria. In this experiment, rumen pH was not impacted by DCAD level, which exactly explained why the Chao index, Ace index, Simpson index and Beta diversity of the three groups were homogeneous. The Shannon index of the HD group was the highest, possibly because NaHCO\\u003csub\\u003e3\\u003c/sub\\u003e was added as a buffer to neutralize gastric acid and was essential for stomach health by creating a suitable internal environment for rumen microorganisms. Reducing DCAD had little effect on Shannon index. In addition, the dominant bacteria of the three groups in this experiment were \\u003cem\\u003eBacteroidetes\\u003c/em\\u003e followed by \\u003cem\\u003eFirmicutes\\u003c/em\\u003e and \\u003cem\\u003eSynergistetes\\u003c/em\\u003e, which was coincide with the results of previous studies on the basis of phylum [\\u003cspan additionalcitationids=\\\"CR62\\\" citationid=\\\"CR61\\\" class=\\\"CitationRef\\\"\\u003e61\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR63\\\" class=\\\"CitationRef\\\"\\u003e63\\u003c/span\\u003e]. In terms of genus level, the relative abundance of \\u003cem\\u003ePrevotella\\u003c/em\\u003e, one of the primary protein-degrading microorganisms of Qianbei miscellaneous goats, was the highest, which was supported by the results of other ruminant studies [\\u003cspan citationid=\\\"CR64\\\" class=\\\"CitationRef\\\"\\u003e64\\u003c/span\\u003e]. The \\u003cem\\u003eFirmicutes\\u003c/em\\u003e are a kind of intestinal bacteria related to obesity can degrade insoluble fiber and play an important role in the process of substance metabolism in rumen. The abundance of \\u003cem\\u003eFirmicutes\\u003c/em\\u003e in HD and LD were 51.95% and 53.98% higher than CON, respectively in the study. The up-regulation in \\u003cem\\u003eFirmicutes\\u003c/em\\u003e abundance might be due to our application of a high forage diet. In summary, neither the reduction of DCAD have a negative effect on the bacterial diversity nor changed the content of the main bacterial genus.\\u003c/p\\u003e \\u003cp\\u003eAs described above, rumen pH, BC, VFA, cellulolytic bacteria population and rumen microflora diversity are crucial in the fermentation status of ruminants. The unaffected these parameters in the present study provide further reliable information and the feasibility on feeding a low-DCAD diet to goats.\\u003c/p\\u003e \\u003cp\\u003eLevel of feed intake is the most important prerequisite for animal growth performance. Generally, pure anionic salt exerts some reduction on feed intake when it was simply mixed into diet, due to its bitter taste and poor palatability [\\u003cspan citationid=\\\"CR65\\\" class=\\\"CitationRef\\\"\\u003e65\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR66\\\" class=\\\"CitationRef\\\"\\u003e66\\u003c/span\\u003e]. Therefore, improving palatability of anionic salt is important for DMI and growth performance. Our previous study [\\u003cspan citationid=\\\"CR67\\\" class=\\\"CitationRef\\\"\\u003e67\\u003c/span\\u003e] showed that DMI of goats fed a low-DCAD did not decrease because the anionic salts were mixed with molasses and dried distillers grains with solubles. Takagi and Block [\\u003cspan citationid=\\\"CR68\\\" class=\\\"CitationRef\\\"\\u003e68\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR69\\\" class=\\\"CitationRef\\\"\\u003e69\\u003c/span\\u003e] also observed that reducing DCAD did not impact DMI containing anionic salts when feeding a total mixture ration. Diets were pelleted in our study, and therefore, they were unaffected for goats fed diet HD, CON, and LD. This indicates that DMI is unaffected by anionic salts inclusion as long as the bitter taste is concealed.\\u003c/p\\u003e \\u003cp\\u003eThe levels of DCAD had no effect on goat final weights. This can be attributed to the similar DMI level and possibly because the goats in this experiment were a local breed, with their adult steady body weight averaging as much as 35\\u0026nbsp;kg, and thus there was limited potential for body weight gain. Accordingly, ADG and FCR did not show difference among goats provided HD, CON, or LD diets.\\u003c/p\\u003e \\u003cp\\u003eNutrients digestibility can be used to measure the digestion and absorption degree of a diet. Correlative analysis in the study demonstrated the digestibility of CP, NDF, ANF, and OM were unaffected for goats fed the three DCAD diets. Apper-Bossard et al. [\\u003cspan citationid=\\\"CR35\\\" class=\\\"CitationRef\\\"\\u003e35\\u003c/span\\u003e] reached similar conclusions. Positive DCAD diet is beneficial to the growth and reproduction of rumen cellulolytic bacteria, and can maintain the activity of digestive enzymes in the digestive tract, thus improving nutrient digestibility [\\u003cspan citationid=\\\"CR70\\\" class=\\\"CitationRef\\\"\\u003e70\\u003c/span\\u003e]. However, different levels of DCAD did not alter the digestibility of CP, NDF, ADF and OM with the rumen pH and rumen cellulolytic bacteria community remained unchanged in this research.\\u003c/p\\u003e \\u003cp\\u003eUrine pH is a useful indicator to monitor the effect of a reduced DCAD diet on acid\\u0026ndash;base balance in goats and sheep [\\u003cspan citationid=\\\"CR71\\\" class=\\\"CitationRef\\\"\\u003e71\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR72\\\" class=\\\"CitationRef\\\"\\u003e72\\u003c/span\\u003e], dairy cows [\\u003cspan citationid=\\\"CR8\\\" class=\\\"CitationRef\\\"\\u003e8\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR73\\\" class=\\\"CitationRef\\\"\\u003e73\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR74\\\" class=\\\"CitationRef\\\"\\u003e74\\u003c/span\\u003e], and buffalo [\\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e4\\u003c/span\\u003e]. This phenomenon can be explained using the strong ion difference theory of Stewart [\\u003cspan citationid=\\\"CR75\\\" class=\\\"CitationRef\\\"\\u003e75\\u003c/span\\u003e], who argued that with reductions of DCAD, the concentration of anions in blood would increase and cause the kidney to expel redundant H\\u003csup\\u003e+\\u003c/sup\\u003e in urine, resulting in lower urine pH. The recommended urine pH is 6.5\\u0026ndash;6.8, because too low a level would exert a burden on the kidneys [\\u003cspan additionalcitationids=\\\"CR77\\\" citationid=\\\"CR76\\\" class=\\\"CitationRef\\\"\\u003e76\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR78\\\" class=\\\"CitationRef\\\"\\u003e78\\u003c/span\\u003e]. Our results showed that urine pH value in goats fed LD was lower than HD and CON. This is accordant with the recommended level, and there is a strong association between DCAD and urine pH in the trial period, suggesting that the LD level is appropriate for the diet of goats.\\u003c/p\\u003e \\u003cp\\u003eMuscle contraction, conduction of nervous impulses, and signal transduction are closely dependent on blood Ca homeostasis. Following the study of Block [\\u003cspan citationid=\\\"CR2\\\" class=\\\"CitationRef\\\"\\u003e2\\u003c/span\\u003e] and subsequent results of ruminant researchers [\\u003cspan citationid=\\\"CR71\\\" class=\\\"CitationRef\\\"\\u003e71\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR79\\\" class=\\\"CitationRef\\\"\\u003e79\\u003c/span\\u003e, \\u003cspan citationid=\\\"CR80\\\" class=\\\"CitationRef\\\"\\u003e80\\u003c/span\\u003e], reducing the DCAD level has been the most commonly used strategy to increase blood Ca levels in transition mammary animals [\\u003cspan citationid=\\\"CR81\\\" class=\\\"CitationRef\\\"\\u003e81\\u003c/span\\u003e]. Our previous study showed that reducing DCAD could increase the plasma Ca concentration of female goats [\\u003cspan citationid=\\\"CR67\\\" class=\\\"CitationRef\\\"\\u003e67\\u003c/span\\u003e]. In the current experiment, the LD caused higher plasma Ca level than HD and CON by 25.97% and 22.27%, respectively, indicating more stable blood Ca homeostasis. Horst et al. [\\u003cspan citationid=\\\"CR82\\\" class=\\\"CitationRef\\\"\\u003e82\\u003c/span\\u003e] and Goff and Horst [\\u003cspan citationid=\\\"CR83\\\" class=\\\"CitationRef\\\"\\u003e83\\u003c/span\\u003e] claimed this may be because LD-induced acidic status enhanced Ca absorption in the gastro-intestine and also increased Ca resorption in the bone, facilitating Ca matrix flow into blood for easier transfer from lumen to blood.\\u003c/p\\u003e \\u003cp\\u003eIn the review of Khanal and Nemere [\\u003cspan citationid=\\\"CR84\\\" class=\\\"CitationRef\\\"\\u003e84\\u003c/span\\u003e] who described three steps for Ca absorption. First, Ca\\u003csup\\u003e2+\\u003c/sup\\u003e influx occurs at the apical membrane via epithelial Ca\\u003csup\\u003e2+\\u003c/sup\\u003e channels, which include the transient receptor potential vanilloid receptor 6 (TRPV6). This step is considered to be rate-limiting for transcellular Ca\\u003csup\\u003e2+\\u003c/sup\\u003e transport [\\u003cspan citationid=\\\"CR85\\\" class=\\\"CitationRef\\\"\\u003e85\\u003c/span\\u003e]. Second, intracellular diffusion is facilitated by the vitamin D-dependent calcium binding protein D9k (CaBP-D9k) [\\u003cspan citationid=\\\"CR86\\\" class=\\\"CitationRef\\\"\\u003e86\\u003c/span\\u003e]. Last, extrusion at the basolateral membrane is achieved by either the Na\\u003csup\\u003e+\\u003c/sup\\u003e/Ca\\u003csup\\u003e2+\\u003c/sup\\u003e exchanger1 (NCX1) or the plasma membrane calcium ATPase 1b (PMCA1b) [\\u003cspan citationid=\\\"CR87\\\" class=\\\"CitationRef\\\"\\u003e87\\u003c/span\\u003e]. The proteins of TRPV6, CaBP-D9k, and PMCA1b are believed to be the three key factors involved in the Ca absorption process, therefore, we speculate that TRPV6, CaBP-D9k, and PMCA1b expression levels in the intestine might be upregulated for animals fed the LD diet. However, a lack of data on TRPV6, CaBP-D9k, and PMCA1b expression in the intestine limits our further discussion. Future work is needed in this area.\\u003c/p\\u003e \\u003cp\\u003eBlood measurements are useful to reflect the metabolic status of animals. Our results showed that all plasma levels of Glu, UN, ALT, AST, AKP, TP, Alb, SOD, GSH-Px, MDA, and CAT were unaffected by DCAD variation. This indicates that reducing DCAD had no effect on nutrient metabolite processes in the plasma. This is supported by previous study. Melendez and Poock [\\u003cspan citationid=\\\"CR9\\\" class=\\\"CitationRef\\\"\\u003e9\\u003c/span\\u003e] reported that lowering DCAD had little effect on blood Alb. Wu et al. [\\u003cspan citationid=\\\"CR67\\\" class=\\\"CitationRef\\\"\\u003e67\\u003c/span\\u003e] found that DCAD level (+\\u0026thinsp;300, +\\u0026thinsp;150, 0, and \\u0026minus;\\u0026thinsp;150) had no significant effect on plasma GSH-Px and MDA content in female goats.\\u003c/p\\u003e \"},{\"header\":\" Conclusion\",\"content\":\" \\u003cp\\u003eReducing DCAD has little influence on rumen status and rumen microbiota, showing no harmful to rumen fermentation of goats. Blood Ca level is increased and urine pH is decreased by DCAD reduction. These results indicate the feasibility of feeding a low-DCAD diets to goats.\\u003c/p\\u003e \"},{\"header\":\"Abbreviations\",\"content\":\" \\u003cdiv class=\\\"DefinitionList\\\"\\u003e \\u003cdiv class=\\\"DefinitionListEntry\\\"\\u003e \\u003cdiv class=\\\"Term\\\"\\u003eDCAD\\u003c/div\\u003e \\u003cdiv class=\\\"Description\\\"\\u003e \\u003cp\\u003eDietary cation-anion difference; HD:High DCAD; CON:Control; LD:Low DCAD; DM:Dry matter; DMI:Dry matter intake; NDF:Neutral detergent fiber; ADF:Acid detergent fiber; AIA:Acid insoluble ash; VFA:Volatile fatty acid; TVFA:Total volatile fatty acid; A/P:Acetate/Propionate; NH\\u003csub\\u003e3\\u003c/sub\\u003e-N:Ammonia nitrogen; CP:Crude protein; OM:Organic matter; ANG:Average net gain; ADG:Average daily gain; F/G:Feed/Gain; FCR:Feed conversion ratio; BC:Buffer capability; Glu:Glucose; UN:Urea nitrogen; ALT:Alanine aminotransferase; AST:Aspartate transaminase; SOD:Superoxide dismutase; AKP:Alkaline phosphatase; ALB:Albumin; TP:Total protein; GSH-Px:Glutathione peroxidase; MDA:Malondialdehyde; CAT:Catalase; SEM:Standard error of means\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/div\\u003e \\u003c/div\\u003e \"},{\"header\":\"Declarations\",\"content\":\" \\u003cp\\u003e \\u003ch2\\u003e Availability of data and materials\\u003c/h2\\u003e \\u003cp\\u003eAll data generated or analyzed during this study are included in this published article.\\u003c/p\\u003e \\u003c/p\\u003e \\u003cp\\u003e \\u003cstrong\\u003e Ethics approval\\u003c/strong\\u003e \\u003cp\\u003eAll procedures with animals received prior approval from the Animal Care and Use Committee of the Guizhou University and followed the regulations and guidelines for animal care and welfare established by the committee.\\u003c/p\\u003e \\u003c/p\\u003e \\u003cp\\u003e \\u003cstrong\\u003e Consent for publication\\u003c/strong\\u003e \\u003cp\\u003eNot applicable.\\u003c/p\\u003e \\u003c/p\\u003e \\u003cp\\u003e \\u003cstrong\\u003e Competing interests\\u003c/strong\\u003e \\u003cp\\u003eAll authors declare that there are no present or potential conflicts of interest among the authors and other people or organizations that could inappropriately bias their work.\\u003c/p\\u003e \\u003c/p\\u003e \\u003ch2\\u003e Funding\\u003c/h2\\u003e \\u003cp\\u003eThis study is financially funded by National Natural Science Foundation of China (31960674), Science and Technology Project of Guizhou Province ([2018]1403), and the Construction Program of Biology First-class Discipline in Guizhou (GNYL[2017]009).\\u003c/p\\u003e \\u003ch2\\u003e Authors\\u0026rsquo; contributions\\u003c/h2\\u003e \\u003cp\\u003eK.Y., X.T., and W.W. conceived and designed the experiment. S.J., L.S., E.H., F.W., Z.G., and Z.M. carried out the farm and the collection of samples. K.Y. and S.J. gathered and analyzed the data, and both took charge for data interpretation and sequencing data (figures and tables), and K.Y. and X.T. wrote the manuscript. T.H. made feasible suggestions for the manuscript. WW acted as overall study director. All authors have read and approved the final manuscript.\\u003c/p\\u003e \\u003ch2\\u003e Acknowledgement\\u003c/h2\\u003e \\u003cp\\u003eThe authors thank the Animal Nutrition Laboratory of Guizhou University for providing the feeding trial site and chemical analysis facilities for this research. The authors also thank International Science Editing for editing this manuscript (\\u003cspan class=\\\"ExternalRef\\\"\\u003e\\u003cspan class=\\\"RefSource\\\"\\u003ehttp://www.internationalscienceediting.com\\u003c/span\\u003e\\u003c/span\\u003e).\\u003c/p\\u003e \"},{\"header\":\"References\",\"content\":\"\\u003col\\u003e\\u003cli\\u003e \\u003cspan\\u003eRiond JL. Animal nutrition and acid-base balance. Eur J Nutrit. 2001;40:245\\u0026ndash;54.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eBlock E. Manipulating dietary anions and cations for prepartum dairy cows to reduce incidence of milk fever. J Dairy Sci. 1984;67:2939\\u0026ndash;48.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eGraham-Thiers PM, Kronfeld DS. Dietary protein influences acid-base balance in sedentary horses. J Equine Vet Sci. 2005;25:434\\u0026ndash;8.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eShahzad MA, Sarwar M, Mahr-un-Nisa. Influence of varying dietary cation anion difference on serum minerals, mineral balance and hypocalcemia in Nili Ravi buffaloes. Livest Sci. 2008;113:52\\u0026ndash;61.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eEdwards LN, Engle TE, Paradis MA, Correa JA, Anderson DB. Persistence of blood changes associated with alteration of the dietary electrolyte balance in commercial pigs after feed withdrawal, transportation, and lairage, and the effects on performance and carcass quality. J Anim Sci. 2010;88:4068\\u0026ndash;77.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eN\\u0026oslash;rgaard JV, H\\u0026oslash;jberg O, S\\u0026oslash;rensen KU, Eriksen J, Medina JMS, Poulsen HD. The effect of long-term acidifying feeding on digesta organic acids, mineral balance, and bone mineralization in growing pigs. Anim Feed Sci Tech. 2014;195:58\\u0026ndash;66.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eHeer F, Dobenecker B, Kienzle E. Effect of cation-anion balance in feed on urine pH in rabbits in comparison with other species. J Anim Physiol Anim Nutr. 2017;101:1324\\u0026ndash;30.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eLeno BM, Ryan CM, Stokol T, Kirk D, Zanzalari KP, Chapman JD, et al. Effects of prepartum dietary cation-anion difference on aspects of peripartum mineral and energy metabolism and performance of multiparous Holstein cows. J Dairy Sci. 2017;100:4604\\u0026ndash;22.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eMelendez P, Poock S. A dairy herd case investigation with very low dietary cation\\u0026ndash;anion difference in prepartum dairy cows. Front Nutr. 2017;4:26.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eAl-Rabadi G, Al-Hijazeen M. Variation in dietary cation-anion differences (DCAD) of feed ingredients in relation to milk fever disease in dairy cattle. Ukr J Ecol. 2018;8:51\\u0026ndash;6.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eDiehl AL, Bernard JK, Tao S, Smith TN, Kirk DJ, McLean DJ, et al. Effect of varying prepartum dietary cation-anion difference and calcium concentration on postpartum mineral and metabolite status and milk production of multiparous cows. J Dairy Sci. 2018;101:9915\\u0026ndash;25.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eRodney RM, Martinez NP, Celi P, Block E, Thomson PC, Wijffels G, et al. Associations between bone and energy metabolism in cows fed diets differing in level of dietary cation-anion difference and supplemented with cholecalciferol or calcidiol. J Dairy Sci. 2018a;101:6581\\u0026ndash;601.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eSlater CJ, Endres EL, Weaver SR, Cheng AA, Lauber MR, Endres SF, et al. Interaction of 5-hydroxy-l-tryptophan and negative dietary cation-anion difference on calcium homeostasis in multiparous peripartum dairy cows. J Dairy Sci. 2018;101:5486\\u0026ndash;501.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eMartinez N, Rodney RM, Block E, Hernandez LL, Nelson CD, Lean IJ, et al. Effects of prepartum dietary cation-anion difference and source of vitamin D in dairy cows: Lactation performance and energy metabolism. J Dairy Sci. 2018a;101:2544\\u0026ndash;62.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eMartinez N, Rodney RM, Block E, Hernandez LL, Nelson CD, Lean IJ, et al. Effects of prepartum dietary cation-anion difference and source of vitamin D in dairy cows: Health and reproductive responses. J Dairy Sci. 2018b;101:2563\\u0026ndash;78.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eRodney RM, Martinez N, Block E, Hernandez LL, Celi P, Nelson CD, et al. Effects of prepartum dietary cation-anion difference and source of vitamin D in dairy cows: Vitamin D, mineral, and bone metabolism. J Dairy Sci. 2018b;101:2519\\u0026ndash;43.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eCollazos C, Lopera C, Santos JEP, Laporta J. Effects of the level and duration of maternal diets with negative dietary cation-anion differences prepartum on calf growth, immunity, and mineral and energy metabolism. J Dairy Sci. 2018;100:9835\\u0026ndash;50.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eLopera C, Zimpel R, Vieira-Neto A, Lopes FR, Ortiz W, Poindexter M, et al. Effects of level of dietary cation-anion difference and duration of prepartum feeding on performance and metabolism of dairy cows. J Dairy Sci. 2018;101:7907\\u0026ndash;29.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eSantos JEP, Lean IJ, Golder HM, Block E. Meta-analysis of the effects of prepartum dietary cation-anion difference on performance and health of dairy cows. J Dairy Sci. 2019;102:2134\\u0026ndash;54.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eLean IJ, Santos JEP, Block E, Golder HM. Effects of prepartum dietary cation-anion difference intake on production and health of dairy cows: A meta-analysis. J Dairy Sci. 2019;102:2103\\u0026ndash;33.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eFanning JP, Hynd PI, Cockcroft PD. The relative roles of the ruminal fluid and epithelium in the aetiology of ruminal acidosis. Small Ruminant Res. 2018;162:57\\u0026ndash;62.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eGiger-Reverdin S. 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Lett Appl Microbiol. 2008;46:132\\u0026ndash;5.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eRussell JB, Muck RE, Weimer PJ. Quantitative analysis of cellulose degradation and growth of cellulolytic bacteria in the rumen. FEMS Microbiol Ecol. 2009;67:183\\u0026ndash;97.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eDai X, Tian Y, Li J, Su X, Wang X, Zhao S, et al. Metatranscriptomic analyses of plant cell wall polysaccharide degradation by microorganisms in the cow rumen. Appl Environ Microb. 2015;81:1375\\u0026ndash;86.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eDeng Y, Huang Z, Ruan W, Zhao M, Miao H, Ren H. Co-inoculation of cellulolytic rumen bacteria with methanogenic sludge to enhance methanogenesis of rice straw. 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Anim Feed Sci Tech. 2019;248:10\\u0026ndash;9.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eJami E, Mizrahi I. Composition and similarity of bovine rumen microbiota across individual animals. PLoS One. 2012;7:e33306.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003ePope PB, Denman SE, Jones M, Tringe SG, Barry K, Malfatti SA, et al. Adaptation to herbivory by the Tammar wallaby includes bacterial and glycoside hydrolase profiles different from other herbivores. P Natl Acad Sci USA. 2010;107:14793\\u0026ndash;8.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eLey RE, Hamady M, Lozupone C, Turnbaugh PJ, Ramey RR, Bircher JS, et al. Evolution of mammals and their gut microbes. Science. 2008;320:1647\\u0026ndash;51.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eMickdam E, Khiaosa-Ard R, Metzler-Zebeli BU, Klevenhusen F, Chizzola R, Zebeli Q. Rumen microbial abundance and fermentation profile during severe subacute ruminal acidosis and its modulation by plant derived alkaloids \\u003cem\\u003ein vitro\\u003c/em\\u003e. Anaerobe. 2016;39:4\\u0026ndash;13.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eWest JW, Mullinix BG, Sandifer TG. Changingdietary electrolyte balance for dairy cows in cool and hot environments. J Dairy Sci. 1991;74:1662\\u0026ndash;74.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eIwaniuk ME. Determination of optimal DCAD concentration and relative effectiveness of potassium versus sodium cation supplementation for maximal feed efficiency in lactating dairy cows. College Park: University of Maryland; 2013.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eWu WX, Yang Y, Zhang JK, Li SL. Reducing dietary cation-anion difference on acid-base balance, plasma minerals level and anti-oxidative stress of female goats. J Integr Agr. 2013;12:1620\\u0026ndash;8.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eTakagi H, Block E. Effects of various dietary cation-anion balances on response to experimentally induced hypocalcemia in sheep. J Dairy Sci. 1991b;74:4215\\u0026ndash;24.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eTakagi H, Block E. Effects of reducing dietary cation-anion balance on calcium kinetics in sheep. J Dairy Sci. 1991c;74:4225\\u0026ndash;37.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eSharif M, Shahzad MA, Mahr-un-Nisa, Sarwar M. Influence of varying levels of dietary cation anion difference on ruminal characteristics, nitrogen metabolism and in situ digestion kinetics in buffalo bulls. Anim Sci J. 2010;81:657\\u0026ndash;65.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eTakagi H, Block E. Effects of manipulating dietary cation-anion balance on macromineral balance in sheep. J Dairy Sci. 1991a;74:4202\\u0026ndash;14.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eLiesegang A. Influence of anionic salts on bone metabolism in periparturient dairy goats and sheep. J Dairy Sci. 2008;91:2449\\u0026ndash;60.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eWu WX, Liu JX, Xu GZ, Ye JA. Calcium homeostasis, acid\\u0026ndash;base balance, and health status in periparturient Holstein cows fed diets with low cation\\u0026ndash;anion difference. Livest Sci. 2008;117:7\\u0026ndash;14.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eRodrigues RO, Cooke RF, Rodrigues SMB, Bastos LN, de Camargo VFS, Gomes KS, et al. Reducing prepartum urine pH by supplementing anionic feed ingredients: Effects on physiological and productive responses of Holstein \\u0026times; Gir cows. J Dairy Sci. 2018;101:9296\\u0026ndash;308.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eStewart PA. Modern quantitative acid-base chemistry. Can J Physiol Pharm. 1983;61:1444\\u0026ndash;61.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eDeGaris PJ, Lean IJ. Milk fever in dairy cows: A review of pathophysiology and control principles. Vet J. 2008;176:58\\u0026ndash;69.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eSeifi HA, Mohri M, Farzaneh N, Nemati H, Nejhad SV. Effects of anionic salts supplementation on blood pH and mineral status, energy metabolism, reproduction and production in transition dairy cows. Res Vet Sci. 2010;89:72\\u0026ndash;7.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eGr\\u0026uuml;nberg W, Donkin SS, Constable PD. Periparturient effects of feeding a low dietary cation-anion difference diet on acid-base, calcium, and phosphorus homeostasis and on intravenous glucose tolerance test in high-producing dairy cows. J Dairy Sci. 2011;94:727\\u0026ndash;45.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eEspino L, Guerrero F, Suarez ML, Santamarina G, Goicoa A, Fidalgo LE. Long-term effects of dietary anion-cation balance on acid-base status and bone morphology in reproducing ewes. J Vet Med A Physiol Pathol Clin Med. 2003;50:488\\u0026ndash;95.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eRoche JR, Petch S, Kay JK. Manipulating the dietary cation-anion difference via drenching to early-lactation dairy cows grazing pasture. J Dairy Sci. 2005;88:264\\u0026ndash;76.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eUSDA. Changes in the U.S. dairy cattle industry, 1991\\u0026ndash;2007, USDA, APHIS: VS CEAH, National Animal Health Monitoring System, Fort Collins, CO. 2007, p.\\u0026nbsp;480.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eHorst RL, Goff JP, Reinhardt TA, Buxton DR. Strategies for preventing milk fever in dairy cattle. J Dairy Sci. 1997;80:1269\\u0026ndash;80.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eGoff JP, Horst RL. Role of acid-base physiology on the pathogenesis of parturient hypocalcemia (milk fever)-The DCAD theory in principle and practice. Acta Vet Scand. 2003;97:1\\u0026ndash;66.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eKhanal RC, Nemere I. Regulation of intestinal calcium transport. Annu Rev Nutr. 2008;28:179\\u0026ndash;96.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eHoenderop JG, Nilius B, Bindels RJ. Calcium absorption across epithelia. Physiol Rev. 2005;85:373\\u0026ndash;422.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eKo SH, Choi KC, Oh GT, Jeung EB. Effect of dietary calcium and 1,25-(OH)\\u003csub\\u003e2\\u003c/sub\\u003eD\\u003csub\\u003e3\\u003c/sub\\u003e on the expression of calcium transport genes in calbindin-D9k and-D28k double knockout mice. Biochem Bioph Res Co. 2009;379:227\\u0026ndash;32.\\u003c/span\\u003e \\u003c/li\\u003e \\u003cli\\u003e \\u003cspan\\u003eChoi KC, An BS, Yang H, Jeung EB. Regulation and molecular mechanisms of calcium transport genes: do they play a role in calcium transport in the uterine endometrium. J Physiol Pharmacol. 2011;62:499\\u0026ndash;504.\\u003c/span\\u003e \\u003c/li\\u003e\\u003c/ol\\u003e\"}],\"fulltextSource\":\"\",\"fullText\":\"\",\"funders\":[],\"hasAdminPriorityOnWorkflow\":false,\"hasManuscriptDocX\":true,\"hasOptedInToPreprint\":true,\"hasPassedJournalQc\":\"\",\"hasAnyPriority\":false,\"hideJournal\":true,\"highlight\":\"\",\"institution\":\"\",\"isAcceptedByJournal\":false,\"isAuthorSuppliedPdf\":false,\"isDeskRejected\":\"\",\"isHiddenFromSearch\":false,\"isInQc\":false,\"isInWorkflow\":false,\"isPdf\":false,\"isPdfUpToDate\":true,\"isWithdrawnOrRetracted\":false,\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"researchsquare\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":true,\"externalIdentity\":\"\",\"sideBox\":\"\",\"snPcode\":\"\",\"submissionUrl\":\"/submission\",\"title\":\"Research Square\",\"twitterHandle\":\"researchsquare\",\"acdcEnabled\":true,\"dfaEnabled\":false,\"editorialSystem\":\"\",\"reportingPortfolio\":\"\",\"inReviewEnabled\":false,\"inReviewRevisionsEnabled\":true},\"keywords\":\"Dietary cation–anion difference, Rumen status, Ruminal cellulolytic bacteria, Rumen microorganisms community, Plasma calcium\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-41136/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-41136/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"\\u003cp\\u003e\\u003cstrong\\u003eBackground: \\u003c/strong\\u003eDietary cation–anion difference (DCAD) has been receiving increased attention in recent years; however, information on the rumen fermentation, cellulolytic bacteria populations, and microbiota of goats fed a low-DCAD diet is less. This study aimed to evaluate the feasibility of feeding a low-DCAD diet for goats with emphasis on rumen fermentation parameters, cellulolytic bacteria populations and microbiota. Growth performance, urine pH, and plasma metabolites were also analyzed as well. \\u003c/p\\u003e\\u003cp\\u003e\\u003cstrong\\u003eMaterials and method: \\u003c/strong\\u003eEighteen goats were randomly allocated to 3 treatments with six replicates of each treatment and 1 goat per replicate. Animals were fed diets with varying DCAD levels at +338 (High DCAD; HD), +152 (Control; CON), and −181 (Low DCAD; LD). This study includes 15-d experimental period and 30-d adaption period. \\u003c/p\\u003e\\u003cp\\u003e\\u003cstrong\\u003eResults: \\u003c/strong\\u003eThe DCAD level did not affect the rumen fermentation parameters including pH, buffering capability, \\u003ca href=\\\"about:blank\\\" rel=\\\"noopener noreferrer\\\" target=\\\"_blank\\\"\\u003eacetic\\u003c/a\\u003e \\u003ca href=\\\"about:blank\\\" rel=\\\"noopener noreferrer\\\" target=\\\"_blank\\\"\\u003eacid\\u003c/a\\u003e, \\u003ca href=\\\"about:blank\\\" rel=\\\"noopener noreferrer\\\" target=\\\"_blank\\\"\\u003epropionic\\u003c/a\\u003e \\u003ca href=\\\"about:blank\\\" rel=\\\"noopener noreferrer\\\" target=\\\"_blank\\\"\\u003eacid\\u003c/a\\u003e, butyric acid, total volatile fatty acids, and ratio of \\u003ca href=\\\"about:blank\\\" rel=\\\"noopener noreferrer\\\" target=\\\"_blank\\\"\\u003eacetic\\u003c/a\\u003e \\u003ca href=\\\"about:blank\\\" rel=\\\"noopener noreferrer\\\" target=\\\"_blank\\\"\\u003eacid\\u003c/a\\u003e/\\u003ca href=\\\"about:blank\\\" rel=\\\"noopener noreferrer\\\" target=\\\"_blank\\\"\\u003epropionic\\u003c/a\\u003e \\u003ca href=\\\"about:blank\\\" rel=\\\"noopener noreferrer\\\" target=\\\"_blank\\\"\\u003eacid\\u003c/a\\u003e (\\u003cem\\u003eP\\u003c/em\\u003e \\u0026gt; 0.05). The 4 main ruminal cellulolytic bacteria populations including \\u003cem\\u003eFibrobacter succinogenes\\u003c/em\\u003e,\\u003cem\\u003e Ruminococcus flavefaciens\\u003c/em\\u003e,\\u003cem\\u003e Butyrivibrio fibrisolvens \\u003c/em\\u003eand \\u003cem\\u003eRuminococcus albus\\u003c/em\\u003e did not differ from DCAD treatments (\\u003cem\\u003eP\\u003c/em\\u003e \\u0026gt; 0.05). The DCAD levels did not affect bacterial richness and diversity indicated by the indices Chao, Ace and Simpson and Shannon, respectively (\\u003cem\\u003eP \\u003c/em\\u003e\\u0026gt; 0.05). Both weighted UniFrac and unweighted UniFrac showed no difference in the composition of rumen microbiota for CON, HD and LD (\\u003cem\\u003eP \\u003c/em\\u003e\\u0026gt; 0.05). At the phylum level, \\u003cem\\u003eBacteroidetes\\u003c/em\\u003e was the predominant phylum followed by \\u003cem\\u003eFirmicutes, Synergistetes, Proteobacteria, Spirochaetae, and Tenericutes\\u003c/em\\u003e, and they showed no difference (\\u003cem\\u003eP \\u003c/em\\u003e\\u0026gt; 0.05) in relative abundances except for \\u003cem\\u003eFirmicutes\\u003c/em\\u003e, which was higher in HD and LD compared to CON (\\u003cem\\u003eP \\u003c/em\\u003e\\u0026lt; 0.05). At the genus level, relative abundance of 11 genera were not affected by DCAD treatments (\\u003cem\\u003eP \\u003c/em\\u003e\\u0026gt; 0.05). Level of DCAD had no effect (\\u003cem\\u003eP\\u003c/em\\u003e \\u0026gt; 0.05) on growth performance including dry matter intake, average net gain, average daily gain, and feed conversion ratio; and nutrients digestibility of crude protein, neutral detergent fiber, acid detergent fiber, and organic matter (\\u003cem\\u003eP\\u003c/em\\u003e \\u0026gt; 0.05). Urine pH in LD was lower than HD and CON (\\u003cem\\u003eP\\u003c/em\\u003e \\u0026lt; 0.05). LD resulted in higher plasma calcium than HD and CON (\\u003cem\\u003eP\\u003c/em\\u003e \\u0026lt; 0.05) but not for other plasma metabolites (\\u003cem\\u003eP\\u003c/em\\u003e \\u0026gt; 0.05). \\u003c/p\\u003e\\u003cp\\u003e\\u003cstrong\\u003eConclusion: \\u003c/strong\\u003eWe conclude that, with regard to the great importance of rumen fermentation, these results suggest that reducing DCAD is unharmful for rumen status and provide the feasibility of feeding a low-DCAD to goats.\\u003c/p\\u003e\",\"manuscriptTitle\":\"Reducing dietary cation–anion difference seldom affects rumen fermentation, cellulolytic bacteria populations, and microbiota in goats\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2020-07-14 19:32:31\",\"doi\":\"10.21203/rs.3.rs-41136/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"researchsquare\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":true,\"externalIdentity\":\"\",\"sideBox\":\"\",\"snPcode\":\"\",\"submissionUrl\":\"/submission\",\"title\":\"Research Square\",\"twitterHandle\":\"researchsquare\",\"acdcEnabled\":true,\"dfaEnabled\":false,\"editorialSystem\":\"\",\"reportingPortfolio\":\"\",\"inReviewEnabled\":false,\"inReviewRevisionsEnabled\":true}}],\"origin\":\"\",\"ownerIdentity\":\"577f8026-6e05-41ee-8e32-7c110cfee94b\",\"owner\":[],\"postedDate\":\"July 14th, 2020\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"posted\",\"subjectAreas\":[{\"id\":156191,\"name\":\"Biotechnology and Bioengineering\"}],\"tags\":[],\"updatedAt\":\"2020-09-02T21:38:53+00:00\",\"versionOfRecord\":[],\"versionCreatedAt\":\"2020-07-14 19:32:31\",\"video\":\"\",\"vorDoi\":\"\",\"vorDoiUrl\":\"\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-41136\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-41136\",\"identity\":\"rs-41136\",\"version\":[\"v1\"]},\"buildId\":\"ehx78VzkSd0WSzXnipQa-\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC-BY-4.0","license_restricted":false}