The Impact of Fortification of Broiler Chicks Meat with Chromium Methionine on Growth Performance, Meat Lipid Oxidation, Antioxidative Status, and Immune Response under High Ambient Temperature

The Impact of Fortification of Broiler Chicks Meat with Chromium Methionine on Growth Performance, Meat Lipid Oxidation, Antioxidative Status, and Immune Response under High Ambient Temperature | 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 Article The Impact of Fortification of Broiler Chicks Meat with Chromium Methionine on Growth Performance, Meat Lipid Oxidation, Antioxidative Status, and Immune Response under High Ambient Temperature Tarek A. Ebeid, Yahya Z. Eid, Mohamed Ragab, Ibrahim T. El-Ratel, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7738702/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 The objective of the current study was to investigate the impacts of dietary chromium methionine (CrMet) supplementation on growth performance, carcass traits, meat quality, meat lipid oxidation, antioxidative properties, and immune responsiveness of broiler chicks under high ambient temperature. A total of 300 1-d-old, unsexed broiler chicks (Cobb 500) were randomly allocated into 4 experimental treatments with 5 replicates (n = 15 birds/pen). The four experimental treatments were: (1) control (the basal diet without CrMet addition); (2) basal diet + 200 µg CrMet/ kg; (3) basal diet + 400 µg CrMet/ kg; and (4) basal diet + 800 µg CrMet/ kg. Dietary CrMet supplementation significantly enhanced growth performance in broilers subjected to heat stress conditions. Chicks fed 400 and 800 µg CrMet/ kg exhibited the lowest abdominal fat. Breast meat Cr content was increased progressively with higher levels of CrMet in the diet. Dietary 400 and 800 µg CrMet/ kg decreased the raw meat's lipid oxidation index (thiobarbituric acid reactive substance, TBARS) at 1-, 3-, and 6-days postmortem. Interestingly, addition of CrMet in the diets improved serum concentrations of total antioxidant capacity, glutathione peroxidase, superoxide dismutase, and antibody titers against Newcastle disease virus and reduced serum concentrations of malondialdehyde, glucose, triglycerides, total cholesterol, and uric acid in broilers raised under high ambient temperature. In conclusion, dietary CrMet (400–800 µg/kg) enhanced growth performance, meat Cr content, meat oxidative stability, serum antioxidative properties, and humoral-mediated immunity in broiler chicks subjected to heat stress conditions, suggesting its potential as a heat stress mitigant in poultry production. Broiler Chromium methionine Antioxidative status Immunity Heat stress Figures Figure 1 Figure 2 Introduction Heat stress is a major factor impacting poultry health and production. Moreover, the recent broiler strains are characterized by rapid growth rate and greater metabolic rates, increasing their susceptibility to heat stress [ 1 – 2 ]. High ambient temperature has an adverse effect on feed intake (FI), live body weight (BW), body weight gain (BWG), feed efficiency, antioxidative properties, and immune responsiveness of chickens and livestock [ 3 – 4 ]. The negative impacts on broiler performance are associated with the disturbance of endocrine and metabolic physiological status [ 1 ]. Moreover, hyperthermia is connected with extreme production of reactive oxygen species (ROS) resulting in oxidative stress leading to lipid peroxidation [ 5 ] and depletion tissue reserves of vitamins and trace minerals [ 6 – 7 ]. Oxidative stress resulted in damaging proteins, DNA, and vital biological molecules. Thus, an equilibrium between ROS generation and antioxidants should be built to preserve immunity, health, and productivity under stress conditions [ 8 – 9 ]. Several nutraceuticals and feed additives are an applicable approach to alleviate the adverse impacts of heat stress in poultry production [ 10 ]. Chromium (Cr) is involved in carbohydrate, lipid, and protein metabolism through activating certain enzymes and it is an essential nutrient for stabilizing proteins and nucleic acids as well as being an active component of a glucose tolerance factor that enhances insulin actions [ 11 ]. Moreover, as a strong and effective antioxidant, organic Cr ameliorated performance, immunity, and metabolism regression in broilers exposed to high ambient temperature [ 12 – 14 ]. Ebrahimzadeh et al. [ 15 ] noted that dietary chromium methionine (CrMet) improved growth performance and carcass characteristics in broilers exposed to thermal stress conditions. Furthermore, the form of dietary Cr is crucial to strengthen its results. Orhan et al. [ 16 ] illustrated that the organic forms of Cr showed the highest absorption rate in comparison with inorganic form (CrCl 3 ) being about 20–30 fold. Khalifah et al. [ 17 ] observed that dietary supplementation of 0.4 and 0.6 g CrMet/kg diet improved laying performance, egg quality characteristics, yolk lipid profile, and antioxidative status in laying Japanese quail under heat stress conditions. These impacts might moderately be attributed to refill of body Cr reserves [ 6 ]. Yet, scientific information existing on meat quality, meat lipid oxidation, antioxidative properties, and immune response in broilers fed CrMet are still limited. It could be hypothesized that dietary CrMet supplementation might increase body Cr reserves, stabilize the usual physiological stability, enhance the antioxidative properties, and improve immune responsiveness under heat stress conditions. Thus, the purpose of the current study was to investigate the influences of supplemental dietary CrMet on growth performance, carcass traits, meat lipid oxidation, antioxidative properties, and immune responsivness of broiler chicks under high ambient temperature. Material and Methods This experiment complied with the guidelines of Kafrelsheikh University, Egypt, and was approved by the institute's Animal Ethics Committee (license number: KFS­IACUC/262/2024). Birds, Housing, and Dietary Treatments A total of 300 1-d-old, unsexed broiler chicks (Cobb 500) were randomly allotted into 4 experimental treatments with 5 replicates (n = 15 birds/pen). Chicks were housed in floor pens contained 6–7 cm wood shavings. The pen dimensions were 350×250×400 cm. The four experimental treatments were: (1) control (the basal diet without CrMet supplementation); (2) basal diet + 200 µg CrMet/ kg; (3) basal diet + 400 µg CrMet/ kg; and (4) basal diet + 800 µg CrMet/ kg. The CrMet utilized in this study was chromium DL-methionine (Availa-Cr 1000), with batch number HPA19122, supplied by Zinpro Corporation in a ready-to-use powdered form. The product contained 2 g of CrMet per 100 g. Chicks were fed a mash starter diet (1–14 d), grower diet (15–28 d) and finisher diet (29–42 d). The experimental diets were mainly composed of ground yellow corn and soybean meal (Table 1 ). The chicks were housed in a semi-closed house, with chamber temperatures maintained between 24 and 28°C and relative humidity ranging from 55% to 70% throughout the trial. Feed and water were provided ad libitum , and the birds received 23 h of light per day. Chick management followed the guidelines of the Cobb Broiler Commercial Management Guide. Table 1 Ingredients and nutrient composition of the basal diet Ingredients Starter Grower Finisher 1–14 day 15–28 day 29–42 day Yellow corn 54.9 64.705 67.545 Soybean meal, 44% 35.8 25 20 Corn gluten meal, 62% 3.495 5 6.35 Vitamin-mineral premix 1 0.3 0.3 0.3 Soybean oil 2.3 1.5 2.5 Dicalcium phosphate 1.3 1.4 1.4 Limestone 1.1 1.1 1 Salt 0.35 0.35 0.35 L-Lysine 0.17 .31 0.3 DL-Methionine 0.25 0.23 0.15 L-Threonine 0.03 0.1 0.1 Phytase enzyme 0.005 0.005 0.005 Total 100 100 100 Calculated composition Crude Protein, % 22.5 19.5 18.3 ME, Kcal/Kg 3035 3080 3180 Crude fiber, % 3.94 3.38 3.1 Ether extract, % 4.88 4.31 5.3 Calcium, % 0.84 0.82 0.77 Available Phosphorus, % 0.45 0.43 0.41 1 Each 3 kg of vitamin-mineral premix contain: 6000000IU vit A, 900000 IU vit D 3 , 40000mg vit E, 2000mg vit K, 2000mg vit.B1, 4000mg vit B2, 2000mg vit B6, 10mg vit B12, 50000mg Niacin, 10000 mg pantothenic acid, 50mg Biotin, 3000mg Folic acid, 250000 mg choline, 8500mg Mn, 50000mg Fe, 50000mg Cu, 200mg I, 100mg Se and 100mg Co. Growth Performance Each chick was individually weighed upon arrival to determine its initial weight. Body weight (BW) in grams was then recorded weekly until six weeks of age. Feed conversion ratio (FCR) was calculated using FI and BWG for each replicate (0–42 d). The FI and FCR were adjusted for mortality when needed. Carcass Characteristics At six weeks of age, 10 broilers from each treatment (2 broilers/ pen) were randomly selected and euthanized for carcass traits evaluation. Live BW, blood, feathers, hot carcass yield, abdominal fat, giblets (liver, heart, and gizzard), and lymphoid organs (bursa of Fabricius, thymus, and spleen) were weighed, and expressed as a percentage of live BW. Meat Chemical and Physical Analyses The chemical composition of all samples was determined by analyzing moisture (950.46 moisture in meat), ether extract (991.36 fat (crude) in meat and meat products), protein (977.14 nitrogen in meat), and ash (920.153 ash of meat) following the procedures recommended by the Association of Official Analytical Chemists [ 18 ]. Water-holding capacity was determined according to the procedure of [ 19 ]. The Cr concentration was determined by atomic absorption spectrophotometry [ 20 ]. Meat Oxidative Stability To assess lipid oxidation products, breast meat samples were packaged in plastic bags and stored in the dark at 4°C. The thiobarbituric acid reactive substances (TBARS) concentration was measured on days 1, 3, and 6 postmortem using the method of Kasapidou et al. [ 21 ]. Blood Plasma Biochemical Constituents At 6 weeks of age, 10 blood samples from each treatment (2 samples per pen) were obtained into heparinized test tubes, centrifuged at 6,000 × g for 10 min at 4°C to separate the plasma, and stored at -20°C until examination. Plasma contents of total protein, albumin, glucose, total cholesterol, triglycerides, uric acid, creatinine, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were spectrophotometrically determined using commercial kits (Stanbio Laboratory, Boerne, TX). Globulin levels were estimated as the difference between total protein and albumin. Plasma concentrations of triiodothyronine (T3), thyroxine (T4), and insulin were assessed using commercial ELISA kits (BioCheck®, Foster City, USA). Blood Plasma Antioxidant Status and Lipid Peroxidation The levels of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), total antioxidant capacity (TAC), and malondialdehyde (MDA) in blood serum were assessed using commercial calorimetry kits of Bio-Diagnostic, Giza, Egypt. The measurements were done according to the manufacturer's instructions. Assay of Serum Newcastle Disease Virus (NDV) Antibody Titer Birds were vaccinated against Newcastle disease virus (NDV) vaccine (LaSota strain) via drinking water 7 days before serum collection. Serum antibody titers against NDV were evaluated by ELISA using a NDV antibody commercial kit (Bio-Chek B.V., Reeuwijk, Netherlands). The test was performed according to Fathi et al. [ 9 ] using the manufacturer’s instructions. Statistical Analysis The statistical differences among treatments were analyzed by one-way ANOVA in a completely randomized design using JMP Ver. 11, Cary, NC, USA (SAS Institute, 2013). The significant differences among means of treatments were compared by using Duncan´s multiple range test where significance levels were detected as first class error at P < 0.05. Results Growth Performance and Carcass Traits The impacts of dietary CrMet addition on growth parameters and carcass traits of broiler chicks reared under high ambient temperature are summarized in Table 2 . The CrMet supplementation enhanced chicken FI and live BW significantly at 42 d of age. Chicks received 400 and 800 µg CrMet/ kg had the lowest significant FCR (1.75 and 1.74; respectively) as compared with control (1.88). The mortality rate of broilers was significantly reduced with supplemental CrMet. Dietary CrMet supplementation did not have a significant impact on hot carcass yield, heart, and gizzard percentages, however, abdominal fat content was significantly reduced. Lymphoid organs (including bursa of Fabricius, thymus, and spleen) were not significantly influenced by experimental treatments. Table 2 Effect of dietary chromium methionine supplementation on growth performance and carcass traits of broiler chickens reared under high ambient temperature Chromium methionine (µg/kg) SEM P-Value 0 200 400 800 Live body weight at 42 d (g) 2240.0 b 2321.88 b 2540.0 a 2575.0 a 38.93 0.0359 Feed intake (g) 4216.0 c 4462.0 b 4452.0 b 4480.0 a 46.21 0.0175 FCR (g:g) 1.88 ab 1.92 a 1.75 ab 1.74 b 0.03 0.0319 Mortality (%) 1.60 a 0.93 c 0.88 c 1.13 b 0.03 0.0256 Hot carcass yield (%) 71.76 71.23 73.16 72.63 1.83 0.0862 Heart (%) 0.33 0.33 0.28 0.29 0.02 0.0953 Liver (%) 3.29 a 2.43 b 2.42 b 2.7 b 0.16 0.0169 Gizzard (%) 1.18 1.25 1.20 1.25 0.10 0.3532 Abdominal fat (%) 1.57 a 1.25 ab 1.07 b 1.06 b 0.11 0.0421 Bursa of Fabricius (%) 0.19 0.18 0.19 0.19 0.02 0.1721 Thymus (%) 0.15 0.13 0.12 0.14 0.02 0.2239 Spleen (%) 0.13 0.12 0.15 0.15 0.01 0.5535 Different letters (a-c) within a raw denote significant differences between treatments (P ≤ 0.05). FCR = feed conversion ratio (feed consumed, g: weight gained, g). Meat Chemical Analysis and Water Holding Capacity The influence of dietary CrMet supplementation on chemical analysis and water holding capacity in breast meat are shown in Table 3 . Breast meat Cr content was increased progressively with higher levels of CrMet in the diet (P < 0.0001). Dietary CrMet supplementation did not affect moisture, protein, and ash content of breast meat. However, dietary treatments reduced ether extract content significantly in breast meat (P = 0.027). Water holding capacity was significantly improved due to dietary CrMet supplementation (P = 0.049). The highest water holding capacity score (6.3) was observed in birds received 400 µg CrMet/ kg. Table 3 Effect of chromium methionine supplementation on breast meat chemical composition and water holding capacity of broiler chickens reared under high ambient temperature Chromium methionine (µg/kg) SEM P-Value 0 200 400 800 Breast muscle Cr (mg/kg) 1.36 d 1.89 c 2.15 b 2.48 a 0.16 < 0.0001 Moisture (%) 73.52 73.49 73.61 73.58 0.52 0.919 Crude protein (%) 22.66 22.34 23.13 22.78 0.26 0.608 Ether extract (%) 1.48 a 0.76 b 0.78 b 0.79 b 0.02 0.027 Ash (%) 3.56 3.61 3.60 3.63 0.18 0.328 Water holding capacity (cm 2 ) 4.4 b 5.3 a 6.3 a 5.8 a 0.27 0.049 Different letters (a-c) within a raw denote significant differences between treatments (P ≤ 0.05). Meat Oxidative Stability The effects of dietary addition of CrMet on lipid oxidation in breast muscle of broiler chickens exposed to high ambient temperature are exhibited in Fig. 1 . Using TBARS as an indicator of lipid oxidation, it was noted that dietary CrMet significantly reduced TBARS levels in breast meat at 1-, 3-, and 6-days postmortem (P ≤ 0.05). Additionally, the 400 and 800 µg CrMet/ kg treatments were the best efficient inhibitor of lipid oxidation, followed by 200 µg CrMet/ kg in comparison with control. Serum Antioxidative Status and Lipid Peroxidation Respecting to the influence of dietary CrMet addition on serum antioxidative status including TAC, GSH-Px, and SOD levels, and lipid peroxidation index (MDA) (Fig. 2 A, B, C, and D), it could be noted that administration of CrMet in the diets elevated the serum TAC, GSH-Px, and SOD activities and decreased MDA concentration in broilers reared under high ambient temperature. Humoral Immunity The influence of dietary CrMet supplementation on antibody titer against NDV in broilers is presented in Fig. 2 E. Interestingly, dietary supplementation of CrMet had a significant positive impact on humoral immune response as determined by antibody titers against NDV under heat stress conditions. Birds supplemented with 200, 400, and 800 µg CrMet/ kg had the highest antibody titers against NDV values (6.00, 5.72 and 6.21 Log2, respectively) in comparison with control group (3.75 Log2). Blood Biochemical Constituents Data concerning the impacts of dietary CrMet inclusion on blood plasma biochemical components in broilers under high ambient temperature, plasma T 3 , T 4 , insulin, total protein, albumin, and globulin were significantly increased due to dietary treatments (Table 4 ). It could be noted that the CrMet supplementation reduced serum glucose, triglycerides, total cholesterol, and uric acid concentrations in comparison with the control treatment (P < 0.05). Contrarily, no significant effect of dietary CrMet supplementation was found for plasma levels of creatine, AST, and ALT. Table 4 The effect of dietary chromium methionine supplementation on blood serum biochemistry of broiler chickens reared under high ambient temperature Chromium methionine (µg/kg) SEM P-Value 0 200 400 800 T3 (ng/ml) 2.64 b 3.18 a 3.22 a 3.25 a 0.09 0.013 T4 (ng/ml) 7.48 b 8.12 a 8.11 a 8.16 a 0.18 0.025 Insulin (U/L) 28.88 d 31.23 c 33.62 b 34.67 a 2.1 0.002 Glucose (mg/dL) 298.49 a 273.53 b 251.22 c 242.67 d 13·5 0.004 Total protein (g/dL) 4.45 c 5.73 b 6.14 ab 6.46 a 0.18 0.008 Albumin (g/dL) 3.27 b 3.23 b 3.70 a 3.64 a 0.02 0.025 Globulin (g/dL) 1.18c 2.5b 2.44b 2.82a 0.02 0.003 Triglycerides (mg/dL) 118.00 a 94.25 b 81.00 bc 79.86 c 2.23 0.002 Total cholesterol (mg/dL) 146.25 a 131.0 b 115.25 c 116.75 c 2.60 0.007 Uric acid (mg/dL) 5.33 a 4.0 b 3.43 c 3.45 c 0.08 0.013 Creatine (mg/dL) 0.51 0.53 0.50 0.55 0.01 0.220 AST (U/L) 229.50 227.0 228.25 230.50 2.57 0.792 ALT(U/L) 2.75 2.50 2.64 2.63 0.06 0.499 Different letters (a-c) within a raw denote significant differences between treatments (P ≤ 0.05). T3 triiodothyronine, T4 thyroxine, AST aspartate-aminotransferase, ALT alanine-amino transferase Discussion Growth Performance and Carcass Traits Findings of the current study illustrated that dietary inclusion of CrMet (400 or 800 µg/ kg) enhanced live BW, elevated FI, improved FCR, reduced mortality rate, and decreased abdominal fat weight under high ambient temperature (Table 2 ). These findings are in harmony with previous studies [ 6 , 12 – 15 ] which indicated that dietary CrMet administration had a beneficial impact on growth performance in broilers under heat stress conditions. Jahanian and Rasouli [ 22 ] observed that addition of CrMet to diet had a positive effect on FI, BWG, and FCR in broiler chickens exposed to thermal stress conditions. Also, Ebrahimzadeh et al. [ 15 ] reported that dietary 800 µg CrMet/ kg increased BW and FI and decreased the abdominal fat content in broilers exposed to heat stress. Hamidi et al. [ 23 ] elucidated that addition of Cr picolinate and Cr picolinate nanoparticles enhanced growth performance indicators in broilers under heat stress conditions. Sahin et al. [ 6 ] noted that increases in dietary Cr picolinate (200, 400, 800, or 1,200 µg/kg) increased BW, FI, and FCR in broilers reared under thermal stress. Youssef et al. [ 24 ] observed that dietary CrMet supplementation (200 and 400 ppb Cr) improved BW, BWG, FI, and FCR, while mortality rate was reduced in broilers. The improvements in BW in the current report might be attributed to the increasing of FI and also to the enhancement of amino acid uptake in tissues and muscle cells by Cr, leading to enhance BW [ 25 ]. Moreover, the growth promoting influences of dietary Cr might be connected with the up-regulation of expressions of skeletal muscle protein and nuclear protein synthesis [ 26 ]. Also, Dalólio et al. [ 14 ] observed that dietary CrMet supplementation increased gene expression of insulin-like growth factor-1 (IGF-1) and reduced heat-shock protein-70 (HSP-70) gene expression in breast tissue of broilers raised under thermal stress conditions. Moreover, Hayat et al. [ 12 ] indicated that Cr propionate addition had a positive effect on the expression of the nutrient transporter genes (SGLT1, GLUT2, rBAT and CAT1) and intestinal histomorphology (villus height, crypt depth and villus height: crypt depth ratio) in broilers, which in turn translated into enhancing growth performance. Dalólio et al. [ 13 ] noted that dietary supplementation of CrMet (0.77 mg/kg) enhanced growth performance and carcass characteristics in broilers subjected to heat stress conditions. As summarized in Table (2), dietary CrMet supplementation significantly increased FI in broilers subjected to high ambient temperature (P < 0.05). It is well known that Cr is an active factor in the glucose tolerance, that enhances the sensitivity of tissue receptors to insulin, leading to increase glucose absorption by cells and increase glucose oxidation [ 27 ]. Thus, it might be assumed that, under heat stress conditions, dietary CrMet supplementation might increase glucose uptake and decrease blood serum glucose resulting in increasing the appetite, leading to the increasing of feed intake. Results presented in Table (4) confirmed the previous assumption, whereas CrMet supplementation increased blood serum insulin and decreased blood serum glucose. Moreover, Dalólio et al. [ 14 ] observed that dietary CrMet supplementation reduced cloacal and mean body temperatures, which might be involved in enhancing FI in broilers subjected to heat stress conditions. Data presented in Table (2) showed that CrMet supplementation reduced abdominal fat significantly. These results are in accordance with several published studies [ 6 , 13 , 24 , 28 ], which stated that Cr supplementation reduced levels of abdominal fat in broilers. Dalólio et al. [ 13 ] noted that dietary inclusion of CrMet (0.77 mg/kg) reduced abdominal fat in broilers subjected to heat stress conditions. In addition, Cr plays a vital role in improving insulin action causing improvements in protein, carbohydrate, and lipid metabolism, leading to decrease the non-esterified fatty acids and supported serum triglycerides elimination [ 29 ], consequently reduced the abdominal fat [ 15 ]. Moreover, at low insulin concentrations, glucose is converted into fat and deposited in adipose tissue [ 25 ]. Meat Cr Concentration and Oxidative Stability As presented in Table 3 , dietary inclusion of CrMet significantly elevated breast muscle Cr concentration in a dose-dependent manner. Previous studies [ 28 , 30 ] noted that utilizing addition of Cr to feed enhanced muscle Cr content. Sahin et al. [ 30 ] explained that dietary Cr enhanced breast muscle, serum, and liver Cr levels significantly. It might be speculated that organic Cr, in form of CrMet, might be joined to proteins via the same codon as methionine, thus its concentration in breast muscle is higher. In Fig. 1 , it is noteworthy that dietary CrMet supplementation decreased TBARS values (the index of lipid oxidation) in breast muscle at 1-, 3-, and 6-days postmortem significantly. These results proved that dietary supplementation with CrMet enhanced the oxidative stability of breast meat throughout refrigerated storing. This improvement in the oxidative stability might be associated with Cr concentration in the breast meat. This hypothesis is consistent with several other studies [ 24 , 30 – 31 ] which indicated that Cr possesses strong antioxidative properties and it is involved in minimizing lipid peroxidation. At the level of gene expression, Sahin et al. [ 30 ] demonstrated that dietary Cr had positive effects on expressions of nuclear factor erythroid 2-related factor 2 (Nrf2; which is responsible for regulating antioxidant enzymes) and nuclear factor kappa B (NF-κB; which is responsible for controlling DNA transcription) in breast muscle. From another point of view, dietary CrMet supplementation significantly reduced ether extract content in breast meat (Table 3 ). Similarly, Hossain et al. [ 28 ] stated that Cr supplementation significantly decreased fat content in breast meat. Collectively, it might be noted that dietary CrMet significantly increased Cr concentration and reduced fat content significantly which involved in improving the oxidative stability leading to extending the shelf-life of chicken meat. Serum Antioxidative Status and Lipid Peroxidation Heat stress is connected with extreme production of ROS resulting in oxidative damage [ 5 ]. Interestingly, one of the main finding of the present work is that inclusion of CrMet in the diets improved the blood serum TAC, GSH-Px and SOD activities and diminished MDA concentration in broiler chicks exposed to high ambient temperature (Fig. 2 A, B, C, and D). These findings are in harmony with other investigations [ 6 , 30 – 31 ] which proved that Cr is regarded as a key mineral in poultry diets due to its potent antioxidative properties, which help in preventing lipid peroxidation induced by heat stress. Sahin et al. [ 30 ] reported that Cr supplementation enhanced serum GSH-Px concentration and decreased serum MDA concentration in broilers under heat stress conditions. Youssef et al. [ 24 ] observed that dietary CrMet inclusion (200 and 400 ppb Cr) improved serum GSH-Px activity and minimized serum MDA content in broiler chickens. Decreasing the MDA levels might be associated with the insulinotropic effect of Cr [ 27 ]. It is well known that insulin is participating in diminishing lipid peroxidation [ 11 ]. Additionally, Dalólio et al. [ 14 ] revealed that inclusion of CrMet reduced serum corticosterone concentration and consequently suppress the oxidative stress in broiler chickens subjected to heat stress. Achieving such positive results is essential, particularly under heat stress conditions. Humoral Immunity and Lymphoid Organs An interesting finding in the present research was the enhancement of antibody titer against NDV due to dietary CrMet administration in broilers under thermal stress conditions (Fig. 2 E) and this result supported those regarding the antioxidative measurements presented above. These findings agree with previous studies implying supplemental Cr [ 22 , 32 – 33 ]. Ebrahimzadeh et al. [ 33 ] stated that CrMet addition improved the antibody titers against NDV and infectious bronchitis virus in broilers suffered from heat stress conditions. Also, Hayat et al. [ 12 ] indicated that Cr propionate supplementation (0.15 mg/kg) increased the antibody titer against NDV and avian influenza H5 in broilers. Lee et al. [ 32 ] postulated that antibody titer against NDV were increased in broilers fed 400 ppb Cr picolinate. Hamidi et al. [ 23 ] elucidated that addition of Cr picolinate and Cr picolinate nanoparticles enhanced the expression of IFN-γ in broiler chickens under heat stress conditions. The precise mechanism through which Cr improves the immune system remains unclear. Nevertheless, one of the consistent results of the present trail was that dietary CrMet increased serum thyroid hormones (Table 4 ). Indeed, physiological thyroid hormone levels are essential for the proper growth, maintenance, and role of both the antibody- and cell-mediated immune responses [ 34 ]. Moreover, it was established that thyroid hormones are involved in triggering of the immunological system constituents (e.g., macrophages and natural killer cells, [ 35 ]) and cytokines production (e.g., interferon-γ and interleukin-2, [ 34 ]). Furthermore, from another point of view, the improvements in immune response might related to the antioxidative properties of Cr, leading to protecting cells from the oxidative stress [ 17 ]. Therefore, it might be speculated that dietary CrMet supplementation could influence the immune function in broiler chicks via its positive effects on T 3 and T 4 concentrations in the present study. Furthermore, by taking into consideration our results in antioxidative properties and lipid peroxidation, it seems more likely that dietary CrMet supplementation may have an important role in overcoming the negative effects of heat stress in broilers under high ambient temperature. Data tabulated in Table (2) showed that lymphoid organs were not significantly influenced by dietary CrMet supplementation. These findings are in accordance with Ebrahimzadeh et al. [ 33 ] who illustrated that supplementing CrMet in the diet did not improve the relative weights of lymphoid organs under heat stress conditions (P > 0.05). Also, Dalólio et al. [ 14 ] demonstrated that inclusion of CrMet supplementation had no significant impact on lymphoid organs weight. Toghyani et al. [ 36 ] indicated that no significant effects were observed in lymphoid organs due to addition of Cr-picolinate to the diet of thermal-stressed broilers. Blood Biochemical Constituents Blood plasma levels of thyroid hormones (T 3 and T 4 ) were elevated with dietary CrMet supplementation (Table 4 ) indicating that dietary Cr might relieve the harmful impacts of thermal stress. These findings might support the findings of performance parameters in the current trail, whereas greater T 3 and T 4 levels with dietary 400 and 800 µg CrMet/ kg supported a greater performance (Table 2 ). These data are in correspondence to Dalólio et al. [ 14 ] demonstrated that inclusion of CrMet improved serum T 3 and T 4 concentrations in broilers exposed to thermal stress. Sahin et al. [ 6 ] postulated that dietary Cr elevated plasma T 3 and T 4 concentrations and enhanced the growth of broilers under thermal stress conditions. It is well established that T 3 is a key hormone regulating animal growth by managing energy balance and protein anabolism [ 37 ]. In Table 4 , dietary CrMet supplementation increased serum insulin and decreased serum glucose in broiler chickens suffered from thermal stress conditions. Similarly, Sahin et al. [ 6 ] confirmed that Cr supplementation heightened plasma insulin and minimized plasma glucose concentrations in broiler chickens raised in high ambient temperature. The Cr has a vital role in glucose metabolism by activating the role of insulin and also Cr is a key component of glucose tolerance, which is involved in controlling blood glucose concentration [ 14 ]. In the present report, inclusion of CrMet reduced serum total cholesterol and triglycerides (P < 0.05; Table 4 ). These data are in agreement with previous studies [ 6 , 13 , 30 ] which illustrated that Cr is involved in lipid metabolism and employs a cholesterol dropping effect under both thermo-neutral and hyperthermia conditions. Dalólio et al. [ 13 ] noted that dietary supplementation of CrMet (0.77 mg/kg) lowered serum concentrations of total cholesterol, triglycerides, and glucose in broilers subjected to heat stress conditions. Youssef et al. [ 24 ] found that dietary CrMet supplementation (200 and 400 ppb Cr) increased concentration of total protein, while decreased concentrations of glucose, total cholesterol, and triglycerides in blood plasma. As shown in Table 4 , dietary CrMet supplementation increased plasma total protein, albumin, and globulin concentrations. Consistent with the findings of the current trail, Sahin et al. [ 6 ] observed that dietary Cr enhanced plasma total protein level. Overall, the results of this study offer strong evidence that dietary Cr may function as a metabolic modulator, helping to restore metabolic balance in broiler chickens exposed to thermal stress conditions. Conclusion Built on the results set, it might be concluded that dietary CrMet (400 ̶ 800 µg CrMet/ kg) enhanced growth performance, improved meat oxidative stability, stabilized the normal physiological balance, and elevated serum antioxidative properties and immune responsiveness in broiler chickens subjected to heat stress. Thus, several advantages could be obtained by addition of CrMet to the diet of commercial broilers reared under high ambient temperature. Declarations Author Contribution: All authors reviewed, discussed, and approved the final version of the manuscript for submission. Conceptualization: Tarek A. Ebeid, Yahya Z. Eid, and M. Ragab conceived and designed the research plan and supervised the study, recording data, sample collection and performed data analysis and interpretation. Ibrahim T. El-Ratel, Mohamed F. Hassan, and Mohammed Aladhadh contributed to laboratory analyses and statistical analysis. Zarroug H. Ibrahim, Ahmed O. Abbas, and Soliman M. Omar participated in the interpretation of results and literature review and contributed to data validation and manuscript editing. Data Availability No datasets were generated or analyzed during the current study. Ethics Approval All animal protocols were approved by the Institutional Animal Care and Use Committee of faculty of agriculture, Kafrelsheikh University, Egypt (license number: KFS­IACUC/262/2024). Competing interests The authors declare that they have no competing interests Acknowledgements The authors are grateful to all members of the Department of Poultry Production, Faculty of Agriculture, Kafrelsheikh University, Egypt for providing technical and scientific assistance. References Wasti S, Sah N, Mishra B (2020) Impact of heat stress on poultry health and performances, and potential mitigation strategies. 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J Appl Poult Res 22(3):382–387. https://doi.org/10.3382/japr.2011-00506 Orhan C, Tuzcu M, Deeh PBD, Sahin N, Komorowski JR, Sahin K (2019) Organic chromium form alleviates the detrimental effects of heat stress on nutrient digestibility and nutrient transporters in laying hens. Biol Trace Elem Res 189(2):529–537. https://doi.org/10.1007/s12011-018-1485-9 Khalifah AM, Kashyout WA, Abdalla SA, Zeweil HS, Zahran SM, Ebeid TA, Dosoky WM (2022) Leverage of chromium methionine supplementation in laying Japanese quail’s diets on performance, quality, and blood traits challenged by heat stress. Adv Anim Vet Sci 10(3):676–684. http://dx.doi.org/10.17582/journal.aavs/2022/10.3.676.684 AOAC (2011) Official methods of analysis, 18th edn. Assoc. Off. Anal. Chem., Washington, DC Bowker B, Zhuang H (2015) Relationship between water-holding capacity and protein denaturation in broiler breast meat. Poult Sci 94(7):1657–1664. 10.3382/ps/pev120 Williams CH, David DJ, Iismaa O (1962) The determination of chromic oxide in faeces samples by atomic absorption spectrophotometry. J Agric Sci 59(3):381–385. https://doi.org/10.1017/S002185960001546X Kasapidou E, Wood JD, Richardson RI, Sinclair LA, Wilkinson RG, Enser M (2012) Effect of vitamin E supplementation and diet on fatty acid composition and on meat colour and lipid oxidation of lamb leg steaks displayed in modified atmosphere packs. Meat Sci 90(4):908–916. https://doi.org/10.1016/j.meatsci.2011.11.031 Jahanian R, Rasouli E (2015) Dietary chromium methionine supplementation could alleviate immunosuppressive effects of heat stress in broiler chicks. J Anim Sci 93(7):3355–3363. https://doi.org/10.2527/jas.2014-8807 Hamidi O, Chamani M, Ghahri H, Sadeghi AA, Malekinejad H, Palangi V (2022) Effects of supplemental chromium nanoparticles on IFN-γ expression of heat stress broilers. Biol Trace Elem Res 200(1):339–347. https://doi.org/10.1007/s12011-021-02634-0 Youssef IMI, Abdo IMI, Elsukkary HFA, El-Kady MF, Elsayed M (2022) Effects of dietary supplementation of chromium methionine chelate on growth performance, oxidative stress, hematological indices, and carcass traits of broiler chickens. Trop Anim Health Prod 54(5):267. https://doi.org/10.1007/s11250-022-03260-1 Mertz W (1993) Chromium in human nutrition: A review. J Nutr 123(4):626–633. https://doi.org/10.1093/jn/123.4.626 Pan YZ, Wu SG, Dai HC, Zhang HJ, Yue HY, Qi GH (2013) Solexa sequencing of microRNAs on chromium metabolism in broiler chicks. J Nutrigenet Nutrigenomics 6(3):137–153. https://doi.org/10.1159/000353703 Gallaher DD, Csallany AS, Shoeman DW, Olson JM (1993) Diabetes increases excretion of urinary malondehyde conjugates in rats. Lipids 28(7):663–666. https://doi.org/10.1007/BF02536063 Hossain SM, Barreto SL, Silva CG (1998) Growth performance and carcass composition of broilers fed supplemental chromium from chromium yeast. Anim Feed Sci Technol 71(3–4):217–228. https://doi.org/10.1016/S0377-8401(97)00160-0 Lien TF, Horng YM, Yang KH (1999) Performance, serum characteristics, carcase traits and lipid metabolism of broilers as affected by supplement of chromium picolinate. Br Poult Sci 40(3):357–363. https://doi.org/10.1080/00071669987458 Sahin N, Hayirli A, Orhan C, Tuzcu M, Akdemir F, Komorowski JR, Sahin K (2017) Effects of the supplemental chromium form on performance and oxidative stress in broilers exposed to heat stress. Poult Scie 96(12):4317–4324. https://doi.org/10.3382/ps/pex249 Rao SVR, Prakash B, Raju MVLN, Panda AK, Kumari RK (2016) Effect of supplementing organic forms of zinc, selenium and chromium on performance, antioxidant and immune responses in broiler chicken reared in tropical summer. Biol Trace Elem Res 172(2):511–520. https://doi.org/10.1007/s12011-015-0587-x Lee DN, Wu FY, Cheng YH, Lin RS, Wu PC (2003) Effects of dietary chromium picolinate supplementation on growth performance and immune responses of broilers. Asian-Aust J Anim Sci 16(2):227–233. https://doi.org/10.5713/ajas.2003.227 Ebrahimzadeh SK, Farhoomand P, Noori K (2012) Immune response of broiler chickens fed diets supplemented with different level of chromium methionine under heat stress conditions. Asian-Australas J Anim Sci 25(2):256–260. https://doi.org/10.5713/ajas.2011.11217 Klecha AJ, Genaro AM, Gorelik G, Barreiro Arcos ML, Silberman DM, Schuman M, Garcia SI, Pirola C, Cremaschi GA (2006) Integrative study of hypothalamus-pituitary-thyroid-immune system interaction: thyroid hormone-mediated modulation of lymphocyte activity through the protein kinase C signaling pathway. J Endocrinol 189(1):45–55. https://doi.org/10.1677/joe.1.06137 Botella-Carretero JI, Prados A, Manzano L, Montero MT, Escribano L, Sancho J, Escobar-Morreale HF (2005) The effects of thyroid hormones on circulating markers of cell-mediated immune response, as studied in patients with differentiated thyroid carcinoma before and during thyroxine withdrawal. Eur J Endocrinol 153(2):223–230. https://doi.org/10.1530/eje.1.01951 Toghyani M, Zarkesh S, Shivazad M, Gheisari A (2007) Immune response of broiler chicks fed chromium picolinate in heat stress condition. J Poult Sci 44:330–334. https://doi.org/10.2141/jpsa.44.330 McNabb FMA (2000) Thyroids. In: Whittow G (ed) Sturkie’s avian physiology, 5th edn. Academic, New York, USA, pp 461–471 Additional Declarations No competing interests reported. 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10:56:12","extension":"xml","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":143703,"visible":true,"origin":"","legend":"","description":"","filename":"541d84d301914d29b46a8dae13cb91a71structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7738702/v1/c71ea063b775f236698778a4.xml"},{"id":93484612,"identity":"791b1b94-b0fe-4c8a-b121-b1b34d77d4c5","added_by":"auto","created_at":"2025-10-14 10:48:12","extension":"html","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":152988,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7738702/v1/7d7a733f856291e84b804cf1.html"},{"id":93484602,"identity":"511a5a84-41be-4d06-8f4d-71079e1b8e9f","added_by":"auto","created_at":"2025-10-14 10:48:11","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":138251,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eEffect of chromium methionine supplementation on oxidative stability (TBARS values) of breast meat at 1, 3, and 6 days postmortem of broiler chickens reared under high ambient temperature. Values are expressed as mean; mean values with different letters are significantly different from each other (P ≤ 0.05)\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"111.png","url":"https://assets-eu.researchsquare.com/files/rs-7738702/v1/0c496c2a5129a02c33bddf74.png"},{"id":93484603,"identity":"6821d8f1-64dc-4195-a8a2-fa0ddfe83e5a","added_by":"auto","created_at":"2025-10-14 10:48:11","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":201366,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eEffect of dietary chromium methionine on total antioxidant capacity (TAC, a), glutathione peroxidase (GSH-Px, b), superoxide dismutase (SOD, c), malondialdehyde (MDA, d), and antibody titers against Newcastle disease virus (e) vaccine in broiler chickens reared under high ambient temperature. Values are expressed as mean; mean values with different letters are significantly different from each other (P ≤ 0.05)\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7738702/v1/34b69715f0cfde5451486425.png"},{"id":97669789,"identity":"81309835-3ca9-47d8-b0d7-9997215c4d5a","added_by":"auto","created_at":"2025-12-08 09:28:57","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1877451,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7738702/v1/f178151f-3b58-475e-ab45-d0a7231ca07b.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"The Impact of Fortification of Broiler Chicks Meat with Chromium Methionine on Growth Performance, Meat Lipid Oxidation, Antioxidative Status, and Immune Response under High Ambient Temperature","fulltext":[{"header":"Introduction","content":"\u003cp\u003eHeat stress is a major factor impacting poultry health and production. Moreover, the recent broiler strains are characterized by rapid growth rate and greater metabolic rates, increasing their susceptibility to heat stress [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. High ambient temperature has an adverse effect on feed intake (FI), live body weight (BW), body weight gain (BWG), feed efficiency, antioxidative properties, and immune responsiveness of chickens and livestock [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. The negative impacts on broiler performance are associated with the disturbance of endocrine and metabolic physiological status [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Moreover, hyperthermia is connected with extreme production of reactive oxygen species (ROS) resulting in oxidative stress leading to lipid peroxidation [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e] and depletion tissue reserves of vitamins and trace minerals [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Oxidative stress resulted in damaging proteins, DNA, and vital biological molecules. Thus, an equilibrium between ROS generation and antioxidants should be built to preserve immunity, health, and productivity under stress conditions [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eSeveral nutraceuticals and feed additives are an applicable approach to alleviate the adverse impacts of heat stress in poultry production [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Chromium (Cr) is involved in carbohydrate, lipid, and protein metabolism through activating certain enzymes and it is an essential nutrient for stabilizing proteins and nucleic acids as well as being an active component of a glucose tolerance factor that enhances insulin actions [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Moreover, as a strong and effective antioxidant, organic Cr ameliorated performance, immunity, and metabolism regression in broilers exposed to high ambient temperature [\u003cspan additionalcitationids=\"CR13\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Ebrahimzadeh et al. [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] noted that dietary chromium methionine (CrMet) improved growth performance and carcass characteristics in broilers exposed to thermal stress conditions. Furthermore, the form of dietary Cr is crucial to strengthen its results. Orhan et al. [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] illustrated that the organic forms of Cr showed the highest absorption rate in comparison with inorganic form (CrCl\u003csub\u003e3\u003c/sub\u003e) being about 20\u0026ndash;30 fold. Khalifah et al. [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] observed that dietary supplementation of 0.4 and 0.6 g CrMet/kg diet improved laying performance, egg quality characteristics, yolk lipid profile, and antioxidative status in laying Japanese quail under heat stress conditions. These impacts might moderately be attributed to refill of body Cr reserves [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Yet, scientific information existing on meat quality, meat lipid oxidation, antioxidative properties, and immune response in broilers fed CrMet are still limited. It could be hypothesized that dietary CrMet supplementation might increase body Cr reserves, stabilize the usual physiological stability, enhance the antioxidative properties, and improve immune responsiveness under heat stress conditions. Thus, the purpose of the current study was to investigate the influences of supplemental dietary CrMet on growth performance, carcass traits, meat lipid oxidation, antioxidative properties, and immune responsivness of broiler chicks under high ambient temperature.\u003c/p\u003e"},{"header":"Material and Methods","content":"\u003cp\u003e This experiment complied with the guidelines of Kafrelsheikh University, Egypt, and was approved by the institute's Animal Ethics Committee (license number: KFS\u0026shy;IACUC/262/2024).\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eBirds, Housing, and Dietary Treatments\u003c/h2\u003e\u003cp\u003eA total of 300 1-d-old, unsexed broiler chicks (Cobb 500) were randomly allotted into 4 experimental treatments with 5 replicates (n\u0026thinsp;=\u0026thinsp;15 birds/pen). Chicks were housed in floor pens contained 6\u0026ndash;7 cm wood shavings. The pen dimensions were 350\u0026times;250\u0026times;400 cm. The four experimental treatments were: (1) control (the basal diet without CrMet supplementation); (2) basal diet\u0026thinsp;+\u0026thinsp;200 \u0026micro;g CrMet/ kg; (3) basal diet\u0026thinsp;+\u0026thinsp;400 \u0026micro;g CrMet/ kg; and (4) basal diet\u0026thinsp;+\u0026thinsp;800 \u0026micro;g CrMet/ kg. The CrMet utilized in this study was chromium DL-methionine (Availa-Cr 1000), with batch number HPA19122, supplied by Zinpro Corporation in a ready-to-use powdered form. The product contained 2 g of CrMet per 100 g. Chicks were fed a mash starter diet (1\u0026ndash;14 d), grower diet (15\u0026ndash;28 d) and finisher diet (29\u0026ndash;42 d). The experimental diets were mainly composed of ground yellow corn and soybean meal (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The chicks were housed in a semi-closed house, with chamber temperatures maintained between 24 and 28\u0026deg;C and relative humidity ranging from 55% to 70% throughout the trial. Feed and water were provided \u003cem\u003ead libitum\u003c/em\u003e, and the birds received 23 h of light per day. Chick management followed the guidelines of the Cobb Broiler Commercial Management Guide.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003e\u003cb\u003eIngredients and nutrient composition of the basal diet\u003c/b\u003e\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eIngredients\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStarter\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eGrower\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eFinisher\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1\u0026ndash;14 day\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e15\u0026ndash;28 day\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003e29\u0026ndash;42 day\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eYellow corn\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e54.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e64.705\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e67.545\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSoybean meal, 44%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e35.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e20\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCorn gluten meal, 62%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.495\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6.35\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVitamin-mineral premix\u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSoybean oil\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2.5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDicalcium phosphate\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.4\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLimestone\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSalt\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.35\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.35\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.35\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eL-Lysine\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e.31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDL-Methionine\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.23\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.15\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eL-Threonine\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.03\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePhytase enzyme\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.005\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.005\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.005\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTotal\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e100\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e100\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e100\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eCalculated composition\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCrude Protein, %\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e22.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e19.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e18.3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eME, Kcal/Kg\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3035\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3080\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3180\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCrude fiber, %\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.94\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3.38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eEther extract, %\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4.88\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4.31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5.3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCalcium, %\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.84\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.82\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.77\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAvailable Phosphorus, %\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.45\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.43\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.41\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003e\u003csup\u003e1\u003c/sup\u003eEach 3 kg of vitamin-mineral premix contain: 6000000IU vit A, 900000 IU vit D\u003csub\u003e3\u003c/sub\u003e, 40000mg vit E, 2000mg vit K, 2000mg vit.B1, 4000mg vit B2, 2000mg vit B6, 10mg vit B12, 50000mg Niacin, 10000 mg pantothenic acid, 50mg Biotin, 3000mg Folic acid, 250000 mg choline, 8500mg Mn, 50000mg Fe, 50000mg Cu, 200mg I, 100mg Se and 100mg Co.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eGrowth Performance\u003c/h3\u003e\n\u003cp\u003eEach chick was individually weighed upon arrival to determine its initial weight. Body weight (BW) in grams was then recorded weekly until six weeks of age. Feed conversion ratio (FCR) was calculated using FI and BWG for each replicate (0\u0026ndash;42 d). The FI and FCR were adjusted for mortality when needed.\u003c/p\u003e\n\u003ch3\u003eCarcass Characteristics\u003c/h3\u003e\n\u003cp\u003eAt six weeks of age, 10 broilers from each treatment (2 broilers/ pen) were randomly selected and euthanized for carcass traits evaluation. Live BW, blood, feathers, hot carcass yield, abdominal fat, giblets (liver, heart, and gizzard), and lymphoid organs (bursa of Fabricius, thymus, and spleen) were weighed, and expressed as a percentage of live BW.\u003c/p\u003e\n\u003ch3\u003eMeat Chemical and Physical Analyses\u003c/h3\u003e\n\u003cp\u003eThe chemical composition of all samples was determined by analyzing moisture (950.46 moisture in meat), ether extract (991.36 fat (crude) in meat and meat products), protein (977.14 nitrogen in meat), and ash (920.153 ash of meat) following the procedures recommended by the Association of Official Analytical Chemists [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Water-holding capacity was determined according to the procedure of [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. The Cr concentration was determined by atomic absorption spectrophotometry [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e\n\u003ch3\u003eMeat Oxidative Stability\u003c/h3\u003e\n\u003cp\u003eTo assess lipid oxidation products, breast meat samples were packaged in plastic bags and stored in the dark at 4\u0026deg;C. The thiobarbituric acid reactive substances (TBARS) concentration was measured on days 1, 3, and 6 postmortem using the method of Kasapidou et al. [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e].\u003c/p\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003eBlood Plasma Biochemical Constituents\u003c/h2\u003e\u003cp\u003eAt 6 weeks of age, 10 blood samples from each treatment (2 samples per pen) were obtained into heparinized test tubes, centrifuged at 6,000 \u0026times; g for 10 min at 4\u0026deg;C to separate the plasma, and stored at -20\u0026deg;C until examination. Plasma contents of total protein, albumin, glucose, total cholesterol, triglycerides, uric acid, creatinine, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were spectrophotometrically determined using commercial kits (Stanbio Laboratory, Boerne, TX). Globulin levels were estimated as the difference between total protein and albumin. Plasma concentrations of triiodothyronine (T3), thyroxine (T4), and insulin were assessed using commercial ELISA kits (BioCheck\u0026reg;, Foster City, USA).\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eBlood Plasma Antioxidant Status and Lipid Peroxidation\u003c/h3\u003e\n\u003cp\u003eThe levels of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), total antioxidant capacity (TAC), and malondialdehyde (MDA) in blood serum were assessed using commercial calorimetry kits of Bio-Diagnostic, Giza, Egypt. The measurements were done according to the manufacturer's instructions.\u003c/p\u003e\n\u003ch3\u003eAssay of Serum Newcastle Disease Virus (NDV) Antibody Titer\u003c/h3\u003e\n\u003cp\u003eBirds were vaccinated against Newcastle disease virus (NDV) vaccine (LaSota strain) via drinking water 7 days before serum collection. Serum antibody titers against NDV were evaluated by ELISA using a NDV antibody commercial kit (Bio-Chek B.V., Reeuwijk, Netherlands). The test was performed according to Fathi et al. [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] using the manufacturer\u0026rsquo;s instructions.\u003c/p\u003e\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003eStatistical Analysis\u003c/h2\u003e\u003cp\u003eThe statistical differences among treatments were analyzed by one-way ANOVA in a completely randomized design using JMP Ver. 11, Cary, NC, USA (SAS Institute, 2013). The significant differences among means of treatments were compared by using Duncan\u0026acute;s multiple range test where significance levels were detected as first class error at P\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\u003ch2\u003eGrowth Performance and Carcass Traits\u003c/h2\u003e\u003cp\u003eThe impacts of dietary CrMet addition on growth parameters and carcass traits of broiler chicks reared under high ambient temperature are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. The CrMet supplementation enhanced chicken FI and live BW significantly at 42 d of age. Chicks received 400 and 800 \u0026micro;g CrMet/ kg had the lowest significant FCR (1.75 and 1.74; respectively) as compared with control (1.88). The mortality rate of broilers was significantly reduced with supplemental CrMet. Dietary CrMet supplementation did not have a significant impact on hot carcass yield, heart, and gizzard percentages, however, abdominal fat content was significantly reduced. Lymphoid organs (including bursa of Fabricius, thymus, and spleen) were not significantly influenced by experimental treatments.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003e\u003cb\u003eEffect of dietary chromium methionine supplementation on growth performance and carcass traits of broiler chickens reared under high ambient temperature\u003c/b\u003e\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"7\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e\u003cp\u003eChromium methionine (\u0026micro;g/kg)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eSEM\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eP-Value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e200\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003e400\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003e800\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLive body weight at 42 d (g)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2240.0\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2321.88\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2540.0\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2575.0\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e38.93\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.0359\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFeed intake (g)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4216.0\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4462.0\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e4452.0\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4480.0\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e46.21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.0175\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFCR (g:g)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.88\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.92\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.75\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.74\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.03\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.0319\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMortality (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.60\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.93\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.88\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.13\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.03\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.0256\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHot carcass yield (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e71.76\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e71.23\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e73.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e72.63\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e1.83\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.0862\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHeart (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.33\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.33\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.29\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.0953\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLiver (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.29\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.43\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2.42\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2.7\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.0169\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGizzard (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.20\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.3532\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAbdominal fat (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.57\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.25\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.07\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.06\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.0421\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBursa of Fabricius (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.1721\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eThymus (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.2239\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSpleen (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.5535\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003eDifferent letters (a-c) within a raw denote significant differences between treatments (P\u0026thinsp;\u0026le;\u0026thinsp;0.05).\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003eFCR\u0026thinsp;=\u0026thinsp;feed conversion ratio (feed consumed, g: weight gained, g).\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\u003ch2\u003eMeat Chemical Analysis and Water Holding Capacity\u003c/h2\u003e\u003cp\u003eThe influence of dietary CrMet supplementation on chemical analysis and water holding capacity in breast meat are shown in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. Breast meat Cr content was increased progressively with higher levels of CrMet in the diet (P\u0026thinsp;\u0026lt;\u0026thinsp;0.0001). Dietary CrMet supplementation did not affect moisture, protein, and ash content of breast meat. However, dietary treatments reduced ether extract content significantly in breast meat (P\u0026thinsp;=\u0026thinsp;0.027). Water holding capacity was significantly improved due to dietary CrMet supplementation (P\u0026thinsp;=\u0026thinsp;0.049). The highest water holding capacity score (6.3) was observed in birds received 400 \u0026micro;g CrMet/ kg.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003e\u003cb\u003eEffect of chromium methionine supplementation on breast meat chemical composition and water holding capacity of broiler chickens reared under high ambient temperature\u003c/b\u003e\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"7\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e\u003cp\u003eChromium methionine (\u0026micro;g/kg)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eSEM\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eP-Value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e200\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003e400\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003e800\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBreast muscle Cr (mg/kg)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.36\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.89\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2.15\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2.48\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMoisture (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e73.52\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e73.49\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e73.61\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e73.58\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.52\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.919\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCrude protein (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e22.66\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e22.34\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e23.13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e22.78\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.608\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eEther extract (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.48\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.76\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.78\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.79\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.027\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAsh (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.56\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3.61\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.60\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3.63\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.328\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWater holding capacity (cm\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4.4 \u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5.3 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6.3 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e5.8 \u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.27\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.049\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003eDifferent letters (a-c) within a raw denote significant differences between treatments (P\u0026thinsp;\u0026le;\u0026thinsp;0.05).\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec15\" class=\"Section2\"\u003e\u003ch2\u003eMeat Oxidative Stability\u003c/h2\u003e\u003cp\u003eThe effects of dietary addition of CrMet on lipid oxidation in breast muscle of broiler chickens exposed to high ambient temperature are exhibited in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Using TBARS as an indicator of lipid oxidation, it was noted that dietary CrMet significantly reduced TBARS levels in breast meat at 1-, 3-, and 6-days postmortem (P\u0026thinsp;\u0026le;\u0026thinsp;0.05). Additionally, the 400 and 800 \u0026micro;g CrMet/ kg treatments were the best efficient inhibitor of lipid oxidation, followed by 200 \u0026micro;g CrMet/ kg in comparison with control.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec16\" class=\"Section2\"\u003e\u003ch2\u003eSerum Antioxidative Status and Lipid Peroxidation\u003c/h2\u003e\u003cp\u003eRespecting to the influence of dietary CrMet addition on serum antioxidative status including TAC, GSH-Px, and SOD levels, and lipid peroxidation index (MDA) (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eA, B, C, and D), it could be noted that administration of CrMet in the diets elevated the serum TAC, GSH-Px, and SOD activities and decreased MDA concentration in broilers reared under high ambient temperature.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec17\" class=\"Section2\"\u003e\u003ch2\u003eHumoral Immunity\u003c/h2\u003e\u003cp\u003eThe influence of dietary CrMet supplementation on antibody titer against NDV in broilers is presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eE. Interestingly, dietary supplementation of CrMet had a significant positive impact on humoral immune response as determined by antibody titers against NDV under heat stress conditions. Birds supplemented with 200, 400, and 800 \u0026micro;g CrMet/ kg had the highest antibody titers against NDV values (6.00, 5.72 and 6.21 Log2, respectively) in comparison with control group (3.75 Log2).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec18\" class=\"Section2\"\u003e\u003ch2\u003eBlood Biochemical Constituents\u003c/h2\u003e\u003cp\u003eData concerning the impacts of dietary CrMet inclusion on blood plasma biochemical components in broilers under high ambient temperature, plasma T\u003csub\u003e3\u003c/sub\u003e, T\u003csub\u003e4\u003c/sub\u003e, insulin, total protein, albumin, and globulin were significantly increased due to dietary treatments (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). It could be noted that the CrMet supplementation reduced serum glucose, triglycerides, total cholesterol, and uric acid concentrations in comparison with the control treatment (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Contrarily, no significant effect of dietary CrMet supplementation was found for plasma levels of creatine, AST, and ALT.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003e\u003cb\u003eThe effect of dietary chromium methionine supplementation on blood serum biochemistry of broiler chickens reared under high ambient temperature\u003c/b\u003e\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"7\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e\u003cp\u003eChromium methionine (\u0026micro;g/kg)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eSEM\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eP-Value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e200\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003e400\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003e800\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eT3 (ng/ml)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.64\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3.18\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.22\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3.25\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.09\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.013\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eT4 (ng/ml)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e7.48\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e8.12\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e8.11\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e8.16\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.025\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eInsulin (U/L)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e28.88\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e31.23\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e33.62\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e34.67\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e2.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.002\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlucose (mg/dL)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e298.49\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e273.53\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e251.22\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e242.67\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e13\u0026middot;5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.004\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTotal protein (g/dL)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4.45\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5.73\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6.14\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e6.46\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.008\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAlbumin (g/dL)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.27\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3.23\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.70\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3.64\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.025\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlobulin (g/dL)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.18c\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.5b\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2.44b\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2.82a\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.003\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTriglycerides (mg/dL)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e118.00\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e94.25\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e81.00\u003csup\u003ebc\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e79.86\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e2.23\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.002\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTotal cholesterol (mg/dL)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e146.25\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e131.0\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e115.25\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e116.75\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e2.60\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.007\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUric acid (mg/dL)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5.33\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4.0\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.43\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3.45\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.08\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.013\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCreatine (mg/dL)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.51\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.55\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.220\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAST (U/L)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e229.50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e227.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e228.25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e230.50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e2.57\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.792\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eALT(U/L)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.75\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.50\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2.64\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2.63\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.06\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.499\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003eDifferent letters (a-c) within a raw denote significant differences between treatments (P\u0026thinsp;\u0026le;\u0026thinsp;0.05).\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003e\u003cem\u003eT3\u003c/em\u003e triiodothyronine, \u003cem\u003eT4\u003c/em\u003e thyroxine, \u003cem\u003eAST\u003c/em\u003e aspartate-aminotransferase, \u003cem\u003eALT\u003c/em\u003e alanine-amino transferase\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"Discussion","content":"\u003cdiv id=\"Sec20\" class=\"Section2\"\u003e\u003ch2\u003eGrowth Performance and Carcass Traits\u003c/h2\u003e\u003cp\u003eFindings of the current study illustrated that dietary inclusion of CrMet (400 or 800 \u0026micro;g/ kg) enhanced live BW, elevated FI, improved FCR, reduced mortality rate, and decreased abdominal fat weight under high ambient temperature (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). These findings are in harmony with previous studies [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan additionalcitationids=\"CR13 CR14\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] which indicated that dietary CrMet administration had a beneficial impact on growth performance in broilers under heat stress conditions. Jahanian and Rasouli [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e] observed that addition of CrMet to diet had a positive effect on FI, BWG, and FCR in broiler chickens exposed to thermal stress conditions. Also, Ebrahimzadeh et al. [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] reported that dietary 800 \u0026micro;g CrMet/ kg increased BW and FI and decreased the abdominal fat content in broilers exposed to heat stress. Hamidi et al. [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e] elucidated that addition of Cr picolinate and Cr picolinate nanoparticles enhanced growth performance indicators in broilers under heat stress conditions. Sahin et al. [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] noted that increases in dietary Cr picolinate (200, 400, 800, or 1,200 \u0026micro;g/kg) increased BW, FI, and FCR in broilers reared under thermal stress. Youssef et al. [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e] observed that dietary CrMet supplementation (200 and 400 ppb Cr) improved BW, BWG, FI, and FCR, while mortality rate was reduced in broilers. The improvements in BW in the current report might be attributed to the increasing of FI and also to the enhancement of amino acid uptake in tissues and muscle cells by Cr, leading to enhance BW [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Moreover, the growth promoting influences of dietary Cr might be connected with the up-regulation of expressions of skeletal muscle protein and nuclear protein synthesis [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Also, Dal\u0026oacute;lio et al. [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e] observed that dietary CrMet supplementation increased gene expression of insulin-like growth factor-1 (IGF-1) and reduced heat-shock protein-70 (HSP-70) gene expression in breast tissue of broilers raised under thermal stress conditions. Moreover, Hayat et al. [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] indicated that Cr propionate addition had a positive effect on the expression of the nutrient transporter genes (SGLT1, GLUT2, rBAT and CAT1) and intestinal histomorphology (villus height, crypt depth and villus height: crypt depth ratio) in broilers, which in turn translated into enhancing growth performance. Dal\u0026oacute;lio et al. [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] noted that dietary supplementation of CrMet (0.77 mg/kg) enhanced growth performance and carcass characteristics in broilers subjected to heat stress conditions. As summarized in Table\u0026nbsp;(2), dietary CrMet supplementation significantly increased FI in broilers subjected to high ambient temperature (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). It is well known that Cr is an active factor in the glucose tolerance, that enhances the sensitivity of tissue receptors to insulin, leading to increase glucose absorption by cells and increase glucose oxidation [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. Thus, it might be assumed that, under heat stress conditions, dietary CrMet supplementation might increase glucose uptake and decrease blood serum glucose resulting in increasing the appetite, leading to the increasing of feed intake. Results presented in Table\u0026nbsp;(4) confirmed the previous assumption, whereas CrMet supplementation increased blood serum insulin and decreased blood serum glucose. Moreover, Dal\u0026oacute;lio et al. [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e] observed that dietary CrMet supplementation reduced cloacal and mean body temperatures, which might be involved in enhancing FI in broilers subjected to heat stress conditions.\u003c/p\u003e\u003cp\u003eData presented in Table\u0026nbsp;(2) showed that CrMet supplementation reduced abdominal fat significantly. These results are in accordance with several published studies [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e], which stated that Cr supplementation reduced levels of abdominal fat in broilers. Dal\u0026oacute;lio et al. [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] noted that dietary inclusion of CrMet (0.77 mg/kg) reduced abdominal fat in broilers subjected to heat stress conditions. In addition, Cr plays a vital role in improving insulin action causing improvements in protein, carbohydrate, and lipid metabolism, leading to decrease the non-esterified fatty acids and supported serum triglycerides elimination [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e], consequently reduced the abdominal fat [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Moreover, at low insulin concentrations, glucose is converted into fat and deposited in adipose tissue [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e].\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec21\" class=\"Section2\"\u003e\u003ch2\u003eMeat Cr Concentration and Oxidative Stability\u003c/h2\u003e\u003cp\u003eAs presented in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, dietary inclusion of CrMet significantly elevated breast muscle Cr concentration in a dose-dependent manner. Previous studies [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e] noted that utilizing addition of Cr to feed enhanced muscle Cr content. Sahin et al. [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e] explained that dietary Cr enhanced breast muscle, serum, and liver Cr levels significantly. It might be speculated that organic Cr, in form of CrMet, might be joined to proteins via the same codon as methionine, thus its concentration in breast muscle is higher. In Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, it is noteworthy that dietary CrMet supplementation decreased TBARS values (the index of lipid oxidation) in breast muscle at 1-, 3-, and 6-days postmortem significantly. These results proved that dietary supplementation with CrMet enhanced the oxidative stability of breast meat throughout refrigerated storing. This improvement in the oxidative stability might be associated with Cr concentration in the breast meat. This hypothesis is consistent with several other studies [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e] which indicated that Cr possesses strong antioxidative properties and it is involved in minimizing lipid peroxidation. At the level of gene expression, Sahin et al. [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e] demonstrated that dietary Cr had positive effects on expressions of nuclear factor erythroid 2-related factor 2 (Nrf2; which is responsible for regulating antioxidant enzymes) and nuclear factor kappa B (NF-κB; which is responsible for controlling DNA transcription) in breast muscle. From another point of view, dietary CrMet supplementation significantly reduced ether extract content in breast meat (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Similarly, Hossain et al. [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e] stated that Cr supplementation significantly decreased fat content in breast meat. Collectively, it might be noted that dietary CrMet significantly increased Cr concentration and reduced fat content significantly which involved in improving the oxidative stability leading to extending the shelf-life of chicken meat.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec22\" class=\"Section2\"\u003e\u003ch2\u003eSerum Antioxidative Status and Lipid Peroxidation\u003c/h2\u003e\u003cp\u003eHeat stress is connected with extreme production of ROS resulting in oxidative damage [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Interestingly, one of the main finding of the present work is that inclusion of CrMet in the diets improved the blood serum TAC, GSH-Px and SOD activities and diminished MDA concentration in broiler chicks exposed to high ambient temperature (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eA, B, C, and D). These findings are in harmony with other investigations [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e] which proved that Cr is regarded as a key mineral in poultry diets due to its potent antioxidative properties, which help in preventing lipid peroxidation induced by heat stress. Sahin et al. [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e] reported that Cr supplementation enhanced serum GSH-Px concentration and decreased serum MDA concentration in broilers under heat stress conditions. Youssef et al. [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e] observed that dietary CrMet inclusion (200 and 400 ppb Cr) improved serum GSH-Px activity and minimized serum MDA content in broiler chickens. Decreasing the MDA levels might be associated with the insulinotropic effect of Cr [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. It is well known that insulin is participating in diminishing lipid peroxidation [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Additionally, Dal\u0026oacute;lio et al. [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e] revealed that inclusion of CrMet reduced serum corticosterone concentration and consequently suppress the oxidative stress in broiler chickens subjected to heat stress. Achieving such positive results is essential, particularly under heat stress conditions.\u003c/p\u003e\u003cdiv id=\"Sec23\" class=\"Section3\"\u003e\u003ch2\u003eHumoral Immunity and Lymphoid Organs\u003c/h2\u003e\u003cp\u003eAn interesting finding in the present research was the enhancement of antibody titer against NDV due to dietary CrMet administration in broilers under thermal stress conditions (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eE) and this result supported those regarding the antioxidative measurements presented above. These findings agree with previous studies implying supplemental Cr [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. Ebrahimzadeh et al. [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e] stated that CrMet addition improved the antibody titers against NDV and infectious bronchitis virus in broilers suffered from heat stress conditions. Also, Hayat et al. [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] indicated that Cr propionate supplementation (0.15 mg/kg) increased the antibody titer against NDV and avian influenza H5 in broilers. Lee et al. [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e] postulated that antibody titer against NDV were increased in broilers fed 400 ppb Cr picolinate. Hamidi et al. [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e] elucidated that addition of Cr picolinate and Cr picolinate nanoparticles enhanced the expression of IFN-γ in broiler chickens under heat stress conditions. The precise mechanism through which Cr improves the immune system remains unclear. Nevertheless, one of the consistent results of the present trail was that dietary CrMet increased serum thyroid hormones (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Indeed, physiological thyroid hormone levels are essential for the proper growth, maintenance, and role of both the antibody- and cell-mediated immune responses [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. Moreover, it was established that thyroid hormones are involved in triggering of the immunological system constituents (e.g., macrophages and natural killer cells, [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]) and cytokines production (e.g., interferon-γ and interleukin-2, [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]). Furthermore, from another point of view, the improvements in immune response might related to the antioxidative properties of Cr, leading to protecting cells from the oxidative stress [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Therefore, it might be speculated that dietary CrMet supplementation could influence the immune function in broiler chicks via its positive effects on T\u003csub\u003e3\u003c/sub\u003e and T\u003csub\u003e4\u003c/sub\u003e concentrations in the present study. Furthermore, by taking into consideration our results in antioxidative properties and lipid peroxidation, it seems more likely that dietary CrMet supplementation may have an important role in overcoming the negative effects of heat stress in broilers under high ambient temperature.\u003c/p\u003e\u003cp\u003eData tabulated in Table\u0026nbsp;(2) showed that lymphoid organs were not significantly influenced by dietary CrMet supplementation. These findings are in accordance with Ebrahimzadeh et al. [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e] who illustrated that supplementing CrMet in the diet did not improve the relative weights of lymphoid organs under heat stress conditions (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05). Also, Dal\u0026oacute;lio et al. [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e] demonstrated that inclusion of CrMet supplementation had no significant impact on lymphoid organs weight. Toghyani et al. [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e] indicated that no significant effects were observed in lymphoid organs due to addition of Cr-picolinate to the diet of thermal-stressed broilers.\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Sec24\" class=\"Section2\"\u003e\u003ch2\u003eBlood Biochemical Constituents\u003c/h2\u003e\u003cp\u003eBlood plasma levels of thyroid hormones (T\u003csub\u003e3\u003c/sub\u003e and T\u003csub\u003e4\u003c/sub\u003e) were elevated with dietary CrMet supplementation (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e) indicating that dietary Cr might relieve the harmful impacts of thermal stress. These findings might support the findings of performance parameters in the current trail, whereas greater T\u003csub\u003e3\u003c/sub\u003e and T\u003csub\u003e4\u003c/sub\u003e levels with dietary 400 and 800 \u0026micro;g CrMet/ kg supported a greater performance (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). These data are in correspondence to Dal\u0026oacute;lio et al. [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e] demonstrated that inclusion of CrMet improved serum T\u003csub\u003e3\u003c/sub\u003e and T\u003csub\u003e4\u003c/sub\u003e concentrations in broilers exposed to thermal stress. Sahin et al. [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] postulated that dietary Cr elevated plasma T\u003csub\u003e3\u003c/sub\u003e and T\u003csub\u003e4\u003c/sub\u003e concentrations and enhanced the growth of broilers under thermal stress conditions. It is well established that T\u003csub\u003e3\u003c/sub\u003e is a key hormone regulating animal growth by managing energy balance and protein anabolism [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. In Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, dietary CrMet supplementation increased serum insulin and decreased serum glucose in broiler chickens suffered from thermal stress conditions. Similarly, Sahin et al. [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] confirmed that Cr supplementation heightened plasma insulin and minimized plasma glucose concentrations in broiler chickens raised in high ambient temperature. The Cr has a vital role in glucose metabolism by activating the role of insulin and also Cr is a key component of glucose tolerance, which is involved in controlling blood glucose concentration [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. In the present report, inclusion of CrMet reduced serum total cholesterol and triglycerides (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05; Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). These data are in agreement with previous studies [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e] which illustrated that Cr is involved in lipid metabolism and employs a cholesterol dropping effect under both thermo-neutral and hyperthermia conditions. Dal\u0026oacute;lio et al. [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] noted that dietary supplementation of CrMet (0.77 mg/kg) lowered serum concentrations of total cholesterol, triglycerides, and glucose in broilers subjected to heat stress conditions. Youssef et al. [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e] found that dietary CrMet supplementation (200 and 400 ppb Cr) increased concentration of total protein, while decreased concentrations of glucose, total cholesterol, and triglycerides in blood plasma. As shown in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, dietary CrMet supplementation increased plasma total protein, albumin, and globulin concentrations. Consistent with the findings of the current trail, Sahin et al. [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] observed that dietary Cr enhanced plasma total protein level. Overall, the results of this study offer strong evidence that dietary Cr may function as a metabolic modulator, helping to restore metabolic balance in broiler chickens exposed to thermal stress conditions.\u003c/p\u003e\u003c/div\u003e"},{"header":"Conclusion","content":"\u003cp\u003eBuilt on the results set, it might be concluded that dietary CrMet (400 ̶ 800 \u0026micro;g CrMet/ kg) enhanced growth performance, improved meat oxidative stability, stabilized the normal physiological balance, and elevated serum antioxidative properties and immune responsiveness in broiler chickens subjected to heat stress. Thus, several advantages could be obtained by addition of CrMet to the diet of commercial broilers reared under high ambient temperature.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor Contribution:\u0026nbsp;\u003c/strong\u003eAll authors reviewed, discussed, and approved the final version of the manuscript for submission. Conceptualization: Tarek A. Ebeid, Yahya Z. Eid, and M. Ragab conceived and designed the research plan and supervised the study, recording data, sample collection and performed data analysis and interpretation. Ibrahim T. El-Ratel, Mohamed F. Hassan, and Mohammed Aladhadh contributed to laboratory analyses and statistical analysis. Zarroug H. Ibrahim, Ahmed O. Abbas, and Soliman M. Omar participated in the interpretation of results and literature review and contributed to data validation and manuscript editing.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability\u0026nbsp;\u003c/strong\u003eNo datasets were generated or analyzed during the current study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics Approval\u003c/strong\u003e All animal protocols were approved by the Institutional Animal Care and Use Committee of faculty of agriculture, Kafrelsheikh University, Egypt (license number: KFS\u0026shy;IACUC/262/2024).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors are grateful to all members of the Department of Poultry Production, Faculty of Agriculture, Kafrelsheikh University, Egypt for providing technical and scientific assistance.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eWasti S, Sah N, Mishra B (2020) Impact of heat stress on poultry health and performances, and potential mitigation strategies. 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Academic, New York, USA, pp 461\u0026ndash;471\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":"[email protected]","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":"Broiler, Chromium methionine, Antioxidative status, Immunity, Heat stress","lastPublishedDoi":"10.21203/rs.3.rs-7738702/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7738702/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe objective of the current study was to investigate the impacts of dietary chromium methionine (CrMet) supplementation on growth performance, carcass traits, meat quality, meat lipid oxidation, antioxidative properties, and immune responsiveness of broiler chicks under high ambient temperature. A total of 300 1-d-old, unsexed broiler chicks (Cobb 500) were randomly allocated into 4 experimental treatments with 5 replicates (n\u0026thinsp;=\u0026thinsp;15 birds/pen). The four experimental treatments were: (1) control (the basal diet without CrMet addition); (2) basal diet\u0026thinsp;+\u0026thinsp;200 \u0026micro;g CrMet/ kg; (3) basal diet\u0026thinsp;+\u0026thinsp;400 \u0026micro;g CrMet/ kg; and (4) basal diet\u0026thinsp;+\u0026thinsp;800 \u0026micro;g CrMet/ kg. Dietary CrMet supplementation significantly enhanced growth performance in broilers subjected to heat stress conditions. Chicks fed 400 and 800 \u0026micro;g CrMet/ kg exhibited the lowest abdominal fat. Breast meat Cr content was increased progressively with higher levels of CrMet in the diet. Dietary 400 and 800 \u0026micro;g CrMet/ kg decreased the raw meat's lipid oxidation index (thiobarbituric acid reactive substance, TBARS) at 1-, 3-, and 6-days postmortem. Interestingly, addition of CrMet in the diets improved serum concentrations of total antioxidant capacity, glutathione peroxidase, superoxide dismutase, and antibody titers against Newcastle disease virus and reduced serum concentrations of malondialdehyde, glucose, triglycerides, total cholesterol, and uric acid in broilers raised under high ambient temperature. In conclusion, dietary CrMet (400\u0026ndash;800 \u0026micro;g/kg) enhanced growth performance, meat Cr content, meat oxidative stability, serum antioxidative properties, and humoral-mediated immunity in broiler chicks subjected to heat stress conditions, suggesting its potential as a heat stress mitigant in poultry production.\u003c/p\u003e","manuscriptTitle":"The Impact of Fortification of Broiler Chicks Meat with Chromium Methionine on Growth Performance, Meat Lipid Oxidation, Antioxidative Status, and Immune Response under High Ambient Temperature","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-14 10:48:07","doi":"10.21203/rs.3.rs-7738702/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","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":"dddc741d-4156-4923-9863-bff6f0f0c1ca","owner":[],"postedDate":"October 14th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-12-04T15:23:49+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-14 10:48:07","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7738702","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7738702","identity":"rs-7738702","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}