Effect of dried Eichhornia crassipes (water hyacinth) supplemented diet on growing Bonsmara steers calves.

Effect of dried Eichhornia crassipes (water hyacinth) supplemented diet on growing Bonsmara steers calves. | 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 Effect of dried Eichhornia crassipes (water hyacinth) supplemented diet on growing Bonsmara steers calves. Lemohang Gladys Makhanya, Klaas-Jan LEEUW, Ingrid M. M. Malebana, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8697296/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 Reducing feed costs while maintaining profitable beef production continues to challenge farmers, increasing the need to identify alternative feed resources. Eichhornia crassipes (water hyacinth; WH), an invasive aquatic plant, has potential as a ruminant feed ingredient; however, its ability to accumulate pollutants raises food-safety concerns. This study evaluated the nutritive value of dried WH in iso-nitrogenous feedlot diets and assessed the presence of heavy metals in tissues of cattle consuming WH. Four diets containing 0%, 25%, 35%, or 45% WH were formulated and fed to weaner cattle. Average daily gain decreased significantly with increasing WH inclusion (P < 0.001), with cattle in the control group achieving 1.60 kg/day compared with 0.83, 0.70, and 0.30 kg/day in the 25%, 35%, and 45% WH treatments, respectively. Feed intake showed a similar declining pattern, and feed conversion ratio worsened at higher levels of WH inclusion. Heavy metals were not detected in liver or muscle samples, although copper concentrations decreased numerically as dietary WH increased. The absence of detectable heavy metal residues is encouraging; however, routine screening of WH-fed livestock products remains advisable due to the plant’s capacity to absorb environmental contaminants. Further research is needed to identify post-drying additives or processing strategies that improve the palatability and intake of WH to enhance its value as a cost-effective feed resource for beef cattle. beef cattle invasive plants feedlot nutrition heavy metals alternative feeds Figures Figure 1 Figure 2 Introduction Livestock production in Sub-Saharan Africa (SSA) contributes approximately 20–25% of global output; however, productivity across the region remains low due to inconsistent feed availability and limited access to quality fodder resources (Erdaw, 2023 ). Scarcity of improved pastures, insufficient land for fodder cultivation, and the high cost of concentrate feeds further constrain growth of the livestock sector (Tulu et al., 2023 ). Seasonal fluctuations in forage supply exacerbate these limitations, resulting in inadequate nutrient intake and depressed animal performance. Consequently, livestock product output is projected to remain insufficient despite rapidly increasing consumer demand, with estimates indicating that the region will require up to two-thirds more animal-source foods by 2050 (Salvage, 2011). Reliance on imported livestock products is economically unsustainable, underscoring the need to intensify production systems. Such intensification, however, depends fundamentally on identifying affordable, non-conventional feed resources that do not compete with human food supply. Eichhornia crassipes (water hyacinth; WH) is an invasive, free-floating aquatic plant widely regarded as one of the most problematic weeds in tropical and subtropical regions (Fouzi and Deepani, 2018 ). Its rapid proliferation alters aquatic ecosystems by reducing dissolved oxygen, modifying water chemistry, and disrupting native flora (Hossain et al., 2015 ). Despite these negative ecological impacts, WH has been explored for various uses, including fertilizer, fibre, and phytoremediation, and more recently as a potential livestock feed ingredient (Fouzi and Deepani, 2018 ). Nutrient composition of WH varies with plant age and environment but reports generally indicate moderate to high crude protein content and appreciable fibre and energy values on a dry-matter basis (Ndimele et al., 2011 ; Men et al., 2006 ; Hossain et al., 2015 ). WH leaf meal has also shown promise as a protein supplement in aquaculture diets (Mahmood et al., 2018 ; Saha and Ray, 2011 ). Several studies have confirmed that its nutrients are accessible to ruminants (Teye et al., 2019; Indulekha et al., 2019 ). Although WH is abundant and incurs no production cost, it presents potential risks due to its capacity to accumulate heavy metals such as cadmium, chromium, lead, and metalloids including arsenic (Zhou et al., 2005 ; Shi and Zhao, 2007 ). Research evaluating both its nutritive value and food-safety implications for ruminant production remains limited, particularly in South Africa where chemical characterisation of locally sourced WH is scarce. Earlier work suggested that WH could supply substantial mineral quantities to cattle diets and may be best utilised as hay or silage (Bagnall et al., 1973 ; Masifwa et al., 2001 ; Brendonck, 2003). Its integration into ruminant feeding systems has been recommended for developing countries as a strategy to alleviate feed shortages (Jafari, 2010 ), especially when combined with energy-dense concentrates to enhance digestibility (Aderibigebe and Brown, 1993; Ojeifo et al., 2000 ). Given the growing demand for affordable feed resources and the need to mitigate environmental impacts of WH invasion, this study aimed to evaluate the effect of dried water hyacinth as a dietary protein source on growth performance, carcass characteristics, and potential heavy metal residues in beef cattle. Material and methods. Water hyacinth ( Eichhornia crassipes ) was harvested from Hartbeespoort Dam, Northwest Province, South Africa. The water hyacinth was dried and chemically analysed (Table 1 ). Additional feed ingredients including hominy chop, wheat bran, molasses meal, cottonseed oilcake meal, feed lime, feed-grade urea, salt, and mineral - vitamin premix were procured from Obaro (Pretoria, South Africa). Eragrostis curvula hay and lucerne were obtained from the Agricultural Research Council (ARC), Roodeplaat, Gauteng Province. All feed ingredients were analysed for proximate composition following standard AOAC procedures (AOAC, 2006 ), while fibre fractions, mineral content, and heavy metal concentrations were determined using AOAC ( 2015 ) methods. Diet formulation. Experimental diets were formulated to meet nutrient requirements for fattening cattle according to the National Research Council (NRC, 1996 ). Four iso-nitrogenous diets were prepared with increasing levels of dried water hyacinth: Treatment 1 (T1): 0 g kg⁻¹ DM Treatment 2 (T2): 25 g kg⁻¹ DM Treatment 3 (T3): 35 g kg⁻¹ DM Treatment 4 (T4): 45 g kg⁻¹ DM Animal management and experimental design. The study was conducted at the ARC - Animal Production Institute, Irene Campus (Feedlot Section). Ethical approval was granted by the ARC-AP Animal Ethics Committee (APAEC 18/18). Thirty-four Bonsmara weaner cattle (18 steers and 16 heifers), aged 6–8 months and averaging 180 kg liveweight, were used in the study. All animals were implanted with growth promoters (Revalor-S for steers; Revalor-H for heifers) and treated for viral diseases (Maxitect III), bacterial diseases (Covexin®), internal parasites (Dectomax® ) , and external parasites (Delete-All®) according to manufacturer recommendations (MSD, Isando, South Africa). Weaners were individually housed in stanchions and offered one of the four experimental diets (0%, 25%, 35%, or 45% WH) (Table 2 ) in a completely randomized block design. Each treatment consisted of four to five steers and four heifers (Table 3 ). The feeding trial was conducted over 98 days. Table 1 Chemical composition of Eichhornia crassipes (water hyacinth). Parameters Mean ± SD Proximate Dry matter 95.91 ± 0.202 Crude protein 16.06 ± 0.119 Ash 15.96 ± 0.148 Gross Energy 15.00 ± 0.417 Fiber fractions Neutral detergent fiber 47.07 ± 0.627 Acid detergent fiber 26.66 ± 0.747 Acid detergent lignin 6.30 ± 0.502 Toxic metals (mg/kg) Arsenic 0.75 ± 0.033 Cadmium < 0.5 ± 0.000 Copper 11.0 ± 0.963 Iron 2073 ± 35.670 Lead 2.06 ± 0.264 Mercury < 0.1 ± 0.000 Table 2 Ration composition and estimated nutrient values (%, dry matter basis) of the treatments. Ingredient Treatment 1 Treatment 2 Treatment 3 Treatment 4 Hominy chop Wheat bran Molasse meal Eichhorniacrassipes (WH) Agrostis curvula Lucerne Cotton OCM 1 Feed lime Feed grade urea Feed salt Premix 56.6 15 10 0 5 5 5 1.7 1.2 0.5 0.1 42.2 5 10 25 5 5 5 1.5 0.8 0.5 0.1 37.4 5 10 35 5 0 5 1.5 0.6 0.5 0.1 32.5 0 10 45 5 0 5 1.5 0.5 0.5 0.1 Nutrients Crude Protein (%) Ether Extract (%) Crude Fibre (%) Neutral Detergent Fibre (%) Gross Energy (MJ/kg DM) Calcium (Ca %) Phosphorus (P %) 16.2 5.8 11.3 21.9 18.1 0.9 0.6 15.8 4.7 14.8 27.2 17.4 1.1 0.6 15.5 4.4 15.1 28.9 17.3 1.1 0.6 15.4 4.0 16.4 30.8 17.0 1.2 0.6 Copper (Cu, mg/kg) 5.0 6.0 6.5 6.8 Iron (Fe, mg/kg) 69 562 766 962 1 Oil cake meal, solvent extruded. Table 3 Animal allocation to the 4 treatment diets with graded levels of Eichhornia crassipes Gender Treatment 1 Treatment 2 Treatment 3 Treatment 4 Male 5 4 5 4 Female 4 4 4 4 Data collection . Body weight was recorded at the start of the trial and subsequently at two-week intervals. Daily feed intake (FI) was calculated as the difference between feed offered and orts. Feeding levels were adjusted based on refusals: a 10% reduction was applied when excessive leftovers occurred, whereas a 10% increase was applied when minimal or no refusals were observed. Average daily gain (ADG) was determined as the change in body weight between weighing periods, and feed conversion ratio (FCR) was calculated as weight gain per unit of feed consumed. Manure consistency was scored daily using a 5-point scale, where 1 represented dry faeces with concentric rings and 5 indicated watery diarrhoea with blood. At the end of the feeding period, animals were slaughtered at a Grade D, low-throughput experimental abattoir at ARC-API, Irene (Gauteng Province), following South African Meat Safety Act 40 of 2000 regulations and procedures described by Hoffman ( 2014 ). Carcass traits and classification scores were recorded immediately prior to evisceration. The presence of liver abscesses was assessed for each animal. For heavy metal analysis, meat samples were collected from the longissimus dorsi muscle between the 12th and 13th ribs. Four or five steers and four heifers per treatment were randomly selected for sampling. Concentrations of iron (Fe), copper (Cu), arsenic (As), cadmium (Cd), and lead (Pb) were analysed in both liver and muscle tissues. Data analysis. Data on ADG, feed intake, feed conversion ratio, and heavy metal concentrations were analysed using analysis of variance (ANOVA) under the General Linear Model (GLM) procedure of SAS (2020). Treatment means were separated using Fisher’s Least Significant Difference (LSD) test, with significance declared at p < 0.05. Manure score data were analysed using the chi-square test. Results Table 1 shows the chemical composition (proximate, fiber fraction and toxic elements) of the Eichhornia crassipes (water hyacinth), while treatment diets nutritive value is illustrated in Table 2 . Although not analysed statistically, the values show that in terms of proximate, crude protein (CP), ether extract (EE) and gross energy (GE) were higher in treatments 1 and 2 compared to their counterparts. Treatments 3 and 4 had higher crude fibre (CF) and neutral detergent fibre (NDF) than other treatments. Minerals (calcium, copper, and iron) increased as level of WH increased, except for phosphorus, which was similar across the treatments. Table 4 Effect of dried water hyacinth-based diet on growth performance of Bonsmara steers (n = 8 or 9). Treatment n Average daily gain Feed intake Feed conversion ratio 1 9 1.60 a 9.52 a 5.98 c 2 8 0.82 b 6.07 b 7.57 b 3 9 0.70 b 5.85 b 8.36 b 4 8 0.30 c 4.44 c 14.28 a SEM 0.02 0.58 1.28 LSD 0.13 0.76 1.15 P -value < 0.0001 < 0.0001 < 0.0001 Means within a column with different letters in subscript differs significantly ( P < 0.05). LSD – Least squared difference, SEM – Standard error of the mean Effect of dried WH at different inclusion levels in fattening diets on growth performance of Bonsmara is presented in Table 4 . Feed intake (FI), average daily gain (ADG) and feed conversion ratio (FCR) of the steers differed (P < 0.05) significantly across the treatments. Average daily gain was significantly higher (P < 0.05) in treatment 1 and lower (P 0.05) to each other. Feed intake followed the same trend as (ADG), which was highest (P < 0.05) in treatment 1 and lowest in treatment 4. Treatment 1 had the lowest (P < 0.05) FCR, while treatment 4 had the highest FCR value of 14.28. Table 5 Effect of dietary inclusion levels of dried water hyacinth on Bonsmara steers manure (Chi 2 test = 0.94). TMT Week1 Week2 Week3 Week4 Week5 Week6 1 1.89 2.10 1.76 1.33 1.24 1.11 2 1.64 1.61 1.18 0.89 1.04 1.04 3 1.62 1.75 1.40 1.02 1.17 1.17 4 1.64 1.36 1.32 0.95 1.05 1.05 Effect of water hyacinth-based diets on steers manure is shown in Table 5 . A scale of 1 to 5 was used to score the manure. Across all treatments, manure scores remained low (between 1.1 and 2.1), indicating firm to slightly soft faeces throughout the feeding period. No diarrhoea (scores ≥ 4) was observed in any treatment. In Treatment 1, scores were slightly soft during the first two weeks (1.89 to 2.10) but declined progressively to firmer faeces by Week 6 (1.11). Treatments 2 and 4 showed consistently firm to slightly dry manure (0.89 to 1.64), with the lowest scores occurring from Week 4 onwards. Treatment 3 followed a similar pattern, with initial soft faeces (1.62 to 1.75) that stabilised to firm scores (1.02 to 1.17) thereafter. Average weight gain (AWG) of the steers varied significantly among treatments over the 14-week feeding period (Fig. 1 ). Steers in the treatment 1 consistently showed the highest AWG, with a peak of approximately 3.5 kg/day in week 8. Treatments 2 and 3 showed moderate and relatively stable gains of approximately 0.5 to 1.4 kg/day, with both peaking around weeks 8 to 10. In contrast, steers in treatment 4 had the lowest AWG across all weeks, including a negative gain around week 6. Figure 2 shows feed intake (FI) by steers fed graded levels of water hyacinth-based diets over the 14-week feeding period. Feed intake differed markedly among treatments during the 14-week feeding period. Steers receiving the control diet (treatment 1) consistently recorded the highest FI, increasing from approximately 6.0 kg/day in week 2 to over 11.0 kg/day by week 14. Treatments 2 and 3 showed intermediate and relatively comparable intake patterns, with FI rising from about 4.0 to 4.5 kg/day in week 2 to peaks of 7.5 to 8.0 kg/day in week 14. In contrast, steers fed the highest WH inclusion (45%; Treatment 4) exhibited significantly lower FI across all weeks, starting at approximately 2.5 kg/day in week 2 and reaching only 5.5 kg/day by week 14. Table 6 Effect of heavy metals in graded levels of dried water hyacinth-based diets on liver and meat samples (wet weight) from Bonsmara steers. TMT Cu Fe % moist As Cd Pb 1 25.56a 21.75a 71.5b ND ND ND 2 14.76ab 24.7a 72.6b ND ND ND 3 6.882ab 39.02a 73.1b ND ND ND 4 3.897b 31.96a 75.48a ND ND ND LSD 18.96 17.37 2.18 ND ND ND F-prob 0.81 0.2 0.24 ND ND ND SEM 2.55 2.33 0.293 ND ND ND Means within a column with different letters in subscript differs significantly ( P < 0.05). LSD – Least squared difference, SEM – Standard error of the mean. ND – Not detected . Dietary inclusion of dried water hyacinth had no detectable effect on the presence of arsenic (As), cadmium (Cd), or lead (Pb), as all samples tested negative for these elements across treatments (Table 6 ). Copper (Cu) significantly differed (P 0.05) among treatments, although numerically higher in T3 and to lesser extent in T4. Moisture content was significantly higher (P < 0.05) in T4 compared to other treatments. Overall, no heavy metal contamination was detected, and mineral levels remained within expected biological ranges regardless of dietary WH level. Table 7 Effect of heavy metals on liver and meat samples (wet weight) from Bonsmara steers fed graded levels of dried water hyacinth-based diets regardless of treatment. Cu Fe %moist Liver 28.46a 48.46a 69.54b Muscle 0.77a 13.1b 75.72a LSD 28.46 20.929 1.11 F-prob 0.05 < 0.001 0.002 SEM 1.079 0.988 0.124 Means within a column with different letters in subscript differs significantly ( P < 0.05). LSD – Least squared difference, SEM – Standard error of the mean. ND – Not detected . The collected data for the toxicology (arsenic, cadmium, and lead) was limited and no statistical analysis could be done for liver and meat samples per treatment. Copper concentration and iron concentration was higher (Cu: P = 0.05, Fe: P < 0.001, Table 7 ) in liver than meat, but moisture content was higher (P = 0.002) in meat than in liver. Discussion Unavailability of quality fodder and shortage of improved fodder or pasture have been identified as major causes for low meat production (Wimalarathne and Perera, 2019 ). Water hyacinth has been utilized successfully as livestock feed for ruminants, swine, ducks, geese, and fish due to its high crude protein content and progressive growth. With proper inclusion level to the main ration, WH can be a feasible alternative low-quality roughage such as rice straw, legume straw, hay, and grasses. The WH inhabits freshwater bodies such as tanks, canals, marshes, ponds, rivers, and dams. There is a greater opportunity of utilizing this plant to reduce the feed shortage in the South African livestock feed industry. Utilizing WH as livestock feed is another way of controlling the growth of this plant, apart from biological, chemical, and mechanical control methods. Water hyacinth used in this study was harvested from Hartbeespoort dam. The dam is fed by a few rivers, which are considered highly polluted from human waste and with agricultural affluent (Auchterlonie et al., 2021 ). The chemical composition of WH is shown in Table 1 . The percentage of dry matter, crude protein, ash, and gross energy of the WH was 95.91 ± 0.20, 16.06 ± 0.12, 15.96 ± 0.15 and 15.00 ± 0.42, respectively. Ndimele et al ( 2011 ), reported 23–25% of protein-related matter in dried WH. A study by Men et al. ( 2006 ) showed that percentage of crude protein and ash content of WH were 18.6 ± 0.71 and 16.7 ± 1.95, respectively. The fibre fractions of WH in this study were 47.07 ± 0.63 for neutral detergent fiber, 26.66 ± 0.75 for acid detergent fiber and 6.30 ± 0.50 for acid detergent lignin. Crude fibre content of WH was reported by Men et al. ( 2006 ) as 21.4 ± 0.85. A study by Hossain et al. ( 2015 ), showed that fresh WH had a range of 8.7–9.8, 10.1–11.2, 26.1–27.4, 12.3–12.4 and 1.1–1.8 of dry matter, crude protein, crude fibre, ash, and ether extract, respectively. While Men et al. ( 2006 ) indicated that higher proportion of protein can be found in immature leaves and petioles of the WH than in mature plants, several studies revealed that the chemical composition of the WH varies with season, habitat, and fraction of the weed (Tucker et al., 1981 and Abdelhamid, 1991). Nevertheless, researchers have promoted the use of WH as animal feed as its high water and mineral content, which suggest that the nutritional value may be appropriate for certain animals (Llo et al., 2020). Due to the high levels of cellulose and hemicellulose, Murkherjee and Nandi (2004) recommended the possibility of using WH as feed for ruminants. The minimum amount of crude protein content in fodder for ruminants should be 9%. Now the crude protein contained in either dry or fresh WH is ideal to be utilised for growing cattle feed. Although WH is a good potential for livestock feed owing to its nutrient value, however, the fodder may contain toxic materials from the source of biomass. The heavy metals like cadmium (Cd), lead (Pb), mercury (Hg), and metalloids such as arsenic (As) and fluorine can be absorbed by WH due to greater absorbing capacity (Shi and Zhao, 2007 ). This study shows that the tested WH had As, Cd, Copper (Cu), Iron (Fe), Pd and Hg concentration of 0.75, < 0.5, 11.0, 2073, 2.06 and < 0.1%. When feeding livestock, what is imperative in terms of nutrition and feed safety, is that concentration of the metalloids should not be traceable. If they do, it should not be above the normal threshold. Maximum tolerable level for copper in cattle feeds is estimated at 40 mg/kg, but results vary (NRC 2016). As indicated by NRC 2016, levels of 5 mg/kg or slightly above seem ideal. Dietary estimated concentration for treatments 2, 3 and 5 are higher than the recommended concentration of 5 mg/kg, but do not reach the maximum (40 mg/kg) concentration (Table 2 ). The calculated Fe concentration in the treatment diets (treatments 2, 3 and 4) were above the maximum tolerable concentrations (500 mg/kg, NRC 2016). The Fe content in the rations increased as WH level increased (Table 2 ). The high Fe concentrations can interfere with Cu absorption and lead to Cu deficiency (Bremner et al., 1987 ). This Fe interference with Cu can be observed in the decreasing Cu concentration in the liver, whilst Fe concentration increases (Table 6 ). The present study evaluated the effects of graded levels of dried WH on growth performance, feed utilisation, manure consistency and heavy-metal residues in Bonsmara steers. Overall, the inclusion of WH at 25 to 45% of the diets (treatment 2 to 4) had a clear depressive effect on average daily gain (ADG), feed intake (FI), and feed conversion efficiency/ratio (FCR) (Table 4 ). Steers fed the control diet (treatment) showed performance values consistent with reported growth rates for intensively fed beef weaners (Strydom, 2016 ), while WH inclusion progressively reduced ADG, with the lowest gains observed in steers fed treatment 4. This decline aligns with studies indicating that WH has limitations as a major component in ruminant diets due to its high fibre fraction, low energy density, and poor palatability (Masifwa et al., 2001 ; Hossain et al., 2015 ). Reduced FI in the WH diets provides a direct explanation for the poorer growth performance. Low acceptability of WH, likely due to its fibrous structure and potential presence of secondary metabolites, has been noted in previous studies on cattle and buffaloes (Aderibigbe & Brown, 1993 ; Teye et al., 2019). A contributing to the decrease in performance may be the low level of Cu in the liver. Copper levels on a wet weight basis should exceed 25 ppm (Miranda et al., 2006 ). Levels below this will affect performance negatively, and with the increase in Fe (Table 7 ), Cu availability will be depressed further. Across the 14-week feeding period, the average weight gain (AWG) patterns further illustrate the negative impact of increasing water hyacinth inclusion on growth performance (Fig. 1 ). The control group (treatment 1) consistently outperformed all WH-based treatments, showing higher and more stable gains throughout the trial, including a marked peak around Week 8, coinciding with the period of highest feed intake. In contrast, steers on WH diets displayed reduced and more variable AWG, with steers fed treatment 4 experiencing a pronounced drop below zero around week 6, reflecting insufficient nutrient supply relative to growth requirements. Although all WH treatments showed temporary improvements around weeks 8–10, their gains remained well below the control group, indicating that WH could not sustain optimal growth even when short-term intake was adequate. Feed intake patterns across the 14-week feeding period further demonstrated a consistent reduction in voluntary FI with each increase in WH inclusion (Fig. 2 ). This is consistent with Mahmood et al. ( 2018 ), who observed similar intake depression in fish diets containing WH leaf meal, suggesting that WH may impart reduced palatability or slower ruminal degradation rates. The reduced intake is likely the major contributing factor to the decreased ADG and the elevated FCRs observed in higher WH treatments (treatments 2 to 4). In ruminants, diets with high structural fibre and low soluble carbohydrate content typically reduce digestible energy intake, which can limit microbial protein synthesis and consequently depress growth (Van Soest, 1994 ; NRC, 1996 ). Thus, the inferior performance of steers at higher WH inclusion levels is consistent with established rumen physiology. Manure scoring remained within acceptable ranges for all treatments, with no evidence of diarrhoea or digestive disturbances (Table 5 ). Slightly softer faecal scores in WH treatments during some weeks may reflect differences in fibre digestibility or moisture content of the diets, but the absence of severe changes suggests that WH did not negatively affect gut health. Similar findings were reported by Indulekha et al. ( 2019 ), who noted stable faecal consistency in goats fed WH-based rations, indicating good ruminal tolerance despite lower intake. A key concern with WH utilisation in livestock diets is its propensity to accumulate heavy metals, particularly in polluted water systems (Zhou et al., 2005 ; Shi & Zhao, 2007 ). However, the present study showed that As, Cd and Pb were not detected in any meat or liver samples, indicating that WH collected from Hartbeespoort Dam did not contribute hazardous residue levels (Table 6 ). This is consistent with Ndimele et al. ( 2011 ), who reported variable but often low heavy-metal accumulation in WH depending on the degree of water contamination. Copper concentrations decreased numerically with higher WH inclusion, but with statistical significance from T1, and were lower for physiological ranges of liver concentration in cattle (Miranda et al., 2006 ). The absence of detectable toxic metals confirms that WH from this source can be used safely at moderate dietary inclusion levels; however, continued monitoring is advisable due to the plant’s known ability to bioaccumulate pollutants. The heavy metals of As, Cd and Pb were not detected (< 0.02 mg/kg for As, < 0.05 mg/kg for Cd and < 0.01 mg/kg for Pb) in the samples tested. Furthermore, the daily reference intakes for minerals (for adults) are 14 mg for Fe and 1 mg for Cu (European Commission Regulation (EU) Nº 1169/2011). A portion (100 gram) of meat will provide less than that, whilst liver will provide more than the daily requirement. Copper and iron concentrations were significantly higher in the liver compared with meat (Table 7 ), which aligns with the well-established role of the liver as the central storage and regulatory organ for trace minerals in ruminants. The liver contained 28.46 mg/kg Cu than the 0.77 mg/kg in meat, reflecting the physiological tendency of hepatocytes to accumulate Cu for metabolic functions including ceruloplasmin synthesis and antioxidant enzyme activity (Suttle, 2010 ). Similarly, Fe concentration was significantly greater in liver (48.46 mg/kg) than in meat samples (13.1 mg/kg), probably because of the liver’s function as the primary depot for ferritin and hemosiderin and its role in iron homeostasis and erythropoiesis (McDowell, 2003 ). The strong significant difference (P < 0.001) confirms that tissue type rather than dietary treatment was the main determinant of Fe accumulation (Table 7 ). Moisture content showed the reverse pattern, with meat containing significantly higher moisture (75.72%) than liver (69.54%). This is consistent with the structural and biochemical features of skeletal muscle, which contains abundant myofibrillar proteins that confer high water-binding capacity, resulting in typical moisture levels of 72–77% in ruminant muscle (Lawrie & Ledward, 2006 ). Conclusion Overall, the findings suggest that dried WH can be used safely as a component of beef cattle diets without risk of heavy-metal contamination, but its nutritional limitations significantly constrain growth performance when included above 25% of the diet. The poor feed intake and low energy contribution at higher inclusion levels undermine its value as a primary feed ingredient. Improving WH utilisation may require treatments that enhance palatability and digestibility such as ensiling, supplementation with energy-rich feeds, or combining with molasses or cassava, which have previously shown promise in ruminant feeding trials (Mukherjee & Nandi, 2004 ; Ojeifo et al., 2000 ). Future research should focus on processing methods or feed additives that could improve palatability, adding of a copper source and energy availability to optimise WH inclusion levels for feedlot performance. Declarations Competing interest. The authors have no relevant financial or non-financial interest to disclose. Funding. Our thanks go to Hya Matla – URSINIX for their support and supply of cattle and water hyacinth and the support by the ARC-AP in providing feed ingredients, facilities, personnel and veterinary support for this joint effort. Author contributions. Klaas-Jan leeuw contributed to the study design. Material preparation and data collection by Lemohang Makhanya and Klaas-Jan Leeuw. Data was analysed statistically by Nicolene Cochrane. Manuscript preparation and revisions were done by all authors. Acknowledgements. The authors would like to thank Mr K W Mashiane, J K Mokgase, P M Seboko and P T Motlaphi for their dedication to the care of the animals used in the trial. The ARC Soil, Water and Climate institute and Nutrilab for sample analysis. Data availability. The datasets generated and/or analysed during this study are available on request by the corresponding author. References Aderibigbe AO, Brown AA (1993) Nutritive characteristics of two tropical aquatic weeds for ruminants. Ife J Agric 16–17:42–54. AOAC (2006) Official methods of analysis , 18th edn. Association of Official Analytical Chemists, Gaithersburg, MD. AOAC (2015) Official methods of analysis: determination of heavy metals in food by inductively coupled plasma–mass spectrometry . AOAC International, Gaithersburg, MD. Auchterlonie J, Eden CL, Sheridan C (2021) The phytoremediation potential of water hyacinth: a case study from Hartbeespoort Dam, South Africa. S Afr J Chem Eng 37:31–36. Bagnall LO, Furman TS, Hentges JF Jr, Nolan WJ, Shirley RL (1973) Feed and fiber from affluent-grown water hyacinth. In: Proceedings of the conference, Oklahoma City, Oklahoma, 5–7 March 1974. Balehegn M, Kebreab E, Tolera A, Hunt S, Erickson P, Crane TA, Adesogan AT (2021) Livestock sustainability research in Africa with a focus on the environment. Anim Front 11(4):47–56. Bremner, I., Humphries, W. R., Phillippo, M., Walker, M. J., Morrice, P. C. (1987). Iron-induced copper deficiency in calves: dose-response relationships and interactions with molybdenum and sulphur. Animal Production, Volume 45, Issue 3, December 1987, pp. 403–414. Brendonck L, Maes J, Rommens W, Dekeza N, Nhiwatiwa T, Barson M, Callebaut V, Phiri C, Moreau K, Gratwicke B, Stevens M, Alyn N, Holsters E, Ollevier F, Marshall B (2003). The impact of water hyacinth (Eichhornia crassipes) in a eutrophic subtropical impoundment (Lake Chivero, Zimbabwe). II. Species diversity. Arch Hydrobiol 158(3):389–405. Commission Regulation (EU) No 1169/2011 (2011) On the provision of food information to consumers. Off J Eur Union L304:18. Erdaw MM (2023) Contribution, prospects and trends of livestock production in sub-Saharan Africa: a review. Int J Agric Sustain 21(1):2247776. Fouzi MNM, Deepani MLANR (2018) Water hyacinth (Eichhornia crassipes) leaves as an alternative protein source for feeding early phase of Tilapia (Oreochromis niloticus). Sri Lanka Vet J 65(1). Hoffman I (2014) Official slaughter methods in South Africa. Stockfarm June 2014:64–65. Hossain ME, Sikder H, Kabir MH, Sarma SM (2015) Nutritive value of water hyacinth (Eichhornia crassipes). J Anim Feed Res 5(2):40–44. Indulekha VP, Thomas CG, Anil KS (2019) Utilization of water hyacinth as livestock feed by ensiling with additives. Indian J Weed Sci 51(1):67–71. Jafari N (2010) Ecological and socio-economic utilization of water hyacinth (Eichhornia crassipes Mart Solms). J Appl Sci Environ Manage 14(2):43–49. Lawrie RA, Ledward DA (2006) Lawrie’s meat science , 7th edn. Woodhead Publishing, Cambridge. Mahmood S, Khan N, Iqbal KJ, Ashraf M, Khalique A (2018) Evaluation of water hyacinth (Eichhornia crassipes) supplemented diets on the growth, digestibility and histology of grass carp (Ctenopharyngodon idella) fingerlings. J Appl Anim Res 46(1):24–28. Miranda, M., Cruz, J. M., Lopez-Alonso, M., Benedito, J. L., 2006. Variations in liver and blood copper concentrations in young beef cattle raised in north-west Spain: Associations with breed, sex, age and season. Animal Science 82(02):253–258. Masifwa WF, Twongo T, Denny P (2001) The impact of water hyacinth, Eichhornia crassipes (Mart) Solms, on the abundance and diversity of aquatic macroinvertebrates along the shores of northern Lake Victoria, Uganda. Hydrobiologia 452:79–88. McDowell LR (2003) Minerals in animal and human nutrition , 2nd edn. Elsevier, Amsterdam. Meat Safety Act (No. 40 of 2000). Republic of South Africa. Men LT, Yamasaki S, Caldwell JS, Yamada R, Takada R, Taniguchi T (2006) Effect of farm household income levels and rice-based diet or water hyacinth supplementation on growth/cost performances and meat indices of growing and finishing pigs in the Mekong Delta of Vietnam. Anim Sci J 77(3):320–329. Mukherjee R, Nandi B (2004) Improvement of in vitro digestibility through biological treatment of water hyacinth biomass by two Pleurotus species. Int Biodeterior Biodegradation 53(1):7–12. National Academies of Sciences, Engineering and Medicine (2016) Nutrient requirements of beef cattle , 8th rev edn. National Academies Press, Washington, DC. Ndimele PE, Kumolu-Johnson CA, Anetekhai MA (2011) The invasive aquatic macrophyte water hyacinth: problems and prospects. Res J Environ Sci 5(6):509–520. NRC (1996) Nutrient requirements of beef cattle , 7th edn. National Academy Press, Washington, DC. Ojeifo M, Ekokotu PA, Olele NF, Ekelemu JK (2000) A review of the utilisation of water hyacinth control measures for a noxious weed. In: Proceedings of the International Conference on Water Hyacinth, New-Bussa, 27 Oct–1 Nov 2000, pp 183. Saha S, Ray AK (2011). Evaluation of nutritive value of water hyacinth (Eichhornia crassipes) leaf meal in compound diets for Rohu, Labeo rohita fingerlings after fermentation with two bacterial strains isolated from fish gut. Turkish Journal of Fisheries and Aquatic Sciences. 2011; 11:199–207. Shi G, Zhao Q (2007) Uptake of heavy metals by water hyacinth in polluted waters. J Environ Sci 19(8):1055–1060. Strydom P (2016) Carcass and meat quality of South African beef under feedlot conditions. S Afr J Anim Sci 46(4):348–359. Suttle NF (2010) Mineral nutrition of livestock , 4th edn. CABI Publishing, Wallingford. Teye M, Barku VYA, Odoi FNA, Kyereme C (2021a) Composition of water hyacinth (Eichhornia crassipes) harvested from the Volta Lake, Ghana, and its potential as a feed ingredient in rabbit rations. Adv Anim Vet Sci 9(2):230–237. Teye M, Barku VYA, Odoi FNA, Kyereme C (2021b) Water hyacinth (Eichhornia crassipes) meal in rabbit diets: effects on meat quality and heavy metal content. ACS Food Sci Technol 1:1711–1716. Tham HT (2016) Utilisation of water hyacinth as animal feed. Nova J Eng Appl Sci 4(1):1–16. Tulu D, Gadissa S, Hundessa F, Kebede E (2023) Contribution of climate-smart forage and fodder production for sustainable livestock production and environment: lessons and challenges from Ethiopia. Adv Agric 2023. Van Soest PJ (1994) Nutritional ecology of the ruminant , 2nd edn. Cornell University Press, Ithaca, NY. Wimalarathne HDA, Perera PCD (2019) Potentials of water hyacinth as livestock feed in Sri Lanka. Indian J Weed Sci 51(2):101–105. Zhou W, Tan L, Liu D, Yan H, Zhao M, Zhu D (2005) Research advances of Eichhornia crassipes and its utilization. J Huazhong Agric Univ 24(4):423–428. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8697296","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":586156119,"identity":"4a1ad3a2-ac6b-40e2-a362-150b47ed97a6","order_by":0,"name":"Lemohang Gladys Makhanya","email":"","orcid":"","institution":"Agricultural Research Council","correspondingAuthor":false,"prefix":"","firstName":"Lemohang","middleName":"Gladys","lastName":"Makhanya","suffix":""},{"id":586156120,"identity":"d328c809-74f4-4bed-8de4-6ec819338e36","order_by":1,"name":"Klaas-Jan LEEUW","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA3ElEQVRIiWNgGAWjYBACCXYwZQPnE6GFGUylka7lMAkOk2xmPviYt+28vHn7AcaPX/dYyDPwH36AV4s0M1uyMW/bbcM5ZxKYpWWeSRg2MBwzwKtFjpnHTJp3223GGUBfSEsckEhgYGwgpIX/+2/ebefsgVqYf4O1MLN/IOAwHjZm3m0HEoFa2CQ/gLSw8eC3RbKZzVhy7r/k5Bk8iW3WDAckDNt4eArwapE43vzww5szdrYz2A8fvvnjQJ08P//xDXi1IAHGBmYeIMVGrHqIph8kKR8Fo2AUjIKRAgBm0DoF9EM0ZwAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0002-4807-7619","institution":"Agricultural Research Council","correspondingAuthor":true,"prefix":"","firstName":"Klaas-Jan","middleName":"","lastName":"LEEUW","suffix":""},{"id":586156121,"identity":"8745af6f-0bda-440e-96bf-7525c8ea3c9a","order_by":2,"name":"Ingrid M. M. Malebana","email":"","orcid":"","institution":"Agricultural Research Council","correspondingAuthor":false,"prefix":"","firstName":"Ingrid","middleName":"M. M.","lastName":"Malebana","suffix":""},{"id":586156122,"identity":"8d93e150-37c5-42eb-82b9-10edbf1a406c","order_by":3,"name":"Nicolene Cochrane","email":"","orcid":"","institution":"Agricultural Research Council","correspondingAuthor":false,"prefix":"","firstName":"Nicolene","middleName":"","lastName":"Cochrane","suffix":""}],"badges":[],"createdAt":"2026-01-26 06:57:33","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8697296/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8697296/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":102745411,"identity":"3bc2650e-2ea4-4c9e-9db6-f424493a05c4","added_by":"auto","created_at":"2026-02-16 08:49:14","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":52678,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eAverage weight gain of steers fed increasing levels of dried water hyacinth–based diets over a 14-week feeding period.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8697296/v1/760c50b5ab5481e77c46112d.png"},{"id":102297566,"identity":"e3f87611-75aa-463e-b904-1a57e4ae4f2b","added_by":"auto","created_at":"2026-02-10 10:28:15","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":37199,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eAverage feed intake of steers fed increasing levels of dried water hyacinth–based diets over a 14-week feeding period.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-8697296/v1/ebb64dfa2edd7bf531218cfc.png"},{"id":104780946,"identity":"0404d950-04ab-4e8d-8798-ac59cefc16d8","added_by":"auto","created_at":"2026-03-17 07:54:20","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":917249,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8697296/v1/3b82bcec-8a35-4cba-9ddb-6ca15bfedf21.pdf"}],"financialInterests":"","formattedTitle":"Effect of dried Eichhornia crassipes (water hyacinth) supplemented diet on growing Bonsmara steers calves.","fulltext":[{"header":"Introduction","content":"\u003cp\u003eLivestock production in Sub-Saharan Africa (SSA) contributes approximately 20\u0026ndash;25% of global output; however, productivity across the region remains low due to inconsistent feed availability and limited access to quality fodder resources (Erdaw, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). Scarcity of improved pastures, insufficient land for fodder cultivation, and the high cost of concentrate feeds further constrain growth of the livestock sector (Tulu et al., \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). Seasonal fluctuations in forage supply exacerbate these limitations, resulting in inadequate nutrient intake and depressed animal performance. Consequently, livestock product output is projected to remain insufficient despite rapidly increasing consumer demand, with estimates indicating that the region will require up to two-thirds more animal-source foods by 2050 (Salvage, 2011). Reliance on imported livestock products is economically unsustainable, underscoring the need to intensify production systems. Such intensification, however, depends fundamentally on identifying affordable, non-conventional feed resources that do not compete with human food supply.\u003c/p\u003e \u003cp\u003e \u003cem\u003eEichhornia crassipes\u003c/em\u003e (water hyacinth; WH) is an invasive, free-floating aquatic plant widely regarded as one of the most problematic weeds in tropical and subtropical regions (Fouzi and Deepani, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Its rapid proliferation alters aquatic ecosystems by reducing dissolved oxygen, modifying water chemistry, and disrupting native flora (Hossain et al., \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). Despite these negative ecological impacts, WH has been explored for various uses, including fertilizer, fibre, and phytoremediation, and more recently as a potential livestock feed ingredient (Fouzi and Deepani, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Nutrient composition of WH varies with plant age and environment but reports generally indicate moderate to high crude protein content and appreciable fibre and energy values on a dry-matter basis (Ndimele et al., \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2011\u003c/span\u003e; Men et al., \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2006\u003c/span\u003e; Hossain et al., \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). WH leaf meal has also shown promise as a protein supplement in aquaculture diets (Mahmood et al., \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Saha and Ray, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). Several studies have confirmed that its nutrients are accessible to ruminants (Teye et al., 2019; Indulekha et al., \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2019\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eAlthough WH is abundant and incurs no production cost, it presents potential risks due to its capacity to accumulate heavy metals such as cadmium, chromium, lead, and metalloids including arsenic (Zhou et al., \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2005\u003c/span\u003e; Shi and Zhao, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). Research evaluating both its nutritive value and food-safety implications for ruminant production remains limited, particularly in South Africa where chemical characterisation of locally sourced WH is scarce. Earlier work suggested that WH could supply substantial mineral quantities to cattle diets and may be best utilised as hay or silage (Bagnall et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e1973\u003c/span\u003e; Masifwa et al., \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2001\u003c/span\u003e; Brendonck, 2003). Its integration into ruminant feeding systems has been recommended for developing countries as a strategy to alleviate feed shortages (Jafari, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2010\u003c/span\u003e), especially when combined with energy-dense concentrates to enhance digestibility (Aderibigebe and Brown, 1993; Ojeifo et al., \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2000\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eGiven the growing demand for affordable feed resources and the need to mitigate environmental impacts of WH invasion, this study aimed to evaluate the effect of dried water hyacinth as a dietary protein source on growth performance, carcass characteristics, and potential heavy metal residues in beef cattle.\u003c/p\u003e"},{"header":"Material and methods.","content":"\u003cp\u003eWater hyacinth (\u003cem\u003eEichhornia crassipes\u003c/em\u003e) was harvested from Hartbeespoort Dam, Northwest Province, South Africa. The water hyacinth was dried and chemically analysed (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Additional feed ingredients including hominy chop, wheat bran, molasses meal, cottonseed oilcake meal, feed lime, feed-grade urea, salt, and mineral - vitamin premix were procured from Obaro (Pretoria, South Africa). \u003cem\u003eEragrostis curvula\u003c/em\u003e hay and lucerne were obtained from the Agricultural Research Council (ARC), Roodeplaat, Gauteng Province.\u003c/p\u003e \u003cp\u003eAll feed ingredients were analysed for proximate composition following standard AOAC procedures (AOAC, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2006\u003c/span\u003e), while fibre fractions, mineral content, and heavy metal concentrations were determined using AOAC (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2015\u003c/span\u003e) methods.\u003c/p\u003e \u003cp\u003e \u003cb\u003eDiet formulation.\u003c/b\u003e \u003c/p\u003e \u003cp\u003eExperimental diets were formulated to meet nutrient requirements for fattening cattle according to the National Research Council (NRC, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e1996\u003c/span\u003e). Four iso-nitrogenous diets were prepared with increasing levels of dried water hyacinth:\u003c/p\u003e \u003cp\u003eTreatment 1 (T1): 0 g kg⁻\u0026sup1; DM\u003c/p\u003e \u003cp\u003eTreatment 2 (T2): 25 g kg⁻\u0026sup1; DM\u003c/p\u003e \u003cp\u003eTreatment 3 (T3): 35 g kg⁻\u0026sup1; DM\u003c/p\u003e \u003cp\u003eTreatment 4 (T4): 45 g kg⁻\u0026sup1; DM\u003c/p\u003e \u003cp\u003e \u003cb\u003eAnimal management and experimental design.\u003c/b\u003e \u003c/p\u003e \u003cp\u003eThe study was conducted at the ARC - Animal Production Institute, Irene Campus (Feedlot Section). Ethical approval was granted by the ARC-AP Animal Ethics Committee (APAEC 18/18). Thirty-four Bonsmara weaner cattle (18 steers and 16 heifers), aged 6\u0026ndash;8 months and averaging 180 kg liveweight, were used in the study.\u003c/p\u003e \u003cp\u003eAll animals were implanted with growth promoters (Revalor-S for steers; Revalor-H for heifers) and treated for viral diseases (Maxitect III), bacterial diseases (Covexin\u0026reg;), internal parasites (Dectomax\u0026reg;\u003csup\u003e)\u003c/sup\u003e, and external parasites (Delete-All\u0026reg;) according to manufacturer recommendations (MSD, Isando, South Africa).\u003c/p\u003e \u003cp\u003eWeaners were individually housed in stanchions and offered one of the four experimental diets (0%, 25%, 35%, or 45% WH) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e) in a completely randomized block design. Each treatment consisted of four to five steers and four heifers (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The feeding trial was conducted over 98 days.\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\u003eChemical composition of \u003cem\u003eEichhornia crassipes\u003c/em\u003e (water hyacinth).\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParameters\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cem\u003eProximate\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDry matter\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e95.91\u0026thinsp;\u0026plusmn;\u0026thinsp;0.202\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\u003e16.06\u0026thinsp;\u0026plusmn;\u0026thinsp;0.119\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\u003e15.96\u0026thinsp;\u0026plusmn;\u0026thinsp;0.148\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGross Energy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15.00\u0026thinsp;\u0026plusmn;\u0026thinsp;0.417\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eFiber fractions\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNeutral detergent fiber\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e47.07\u0026thinsp;\u0026plusmn;\u0026thinsp;0.627\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAcid detergent fiber\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e26.66\u0026thinsp;\u0026plusmn;\u0026thinsp;0.747\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAcid detergent lignin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6.30\u0026thinsp;\u0026plusmn;\u0026thinsp;0.502\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eToxic metals\u003c/b\u003e \u003cb\u003e(mg/kg)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eArsenic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.75\u0026thinsp;\u0026plusmn;\u0026thinsp;0.033\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCadmium\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCopper\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11.0\u0026thinsp;\u0026plusmn;\u0026thinsp;0.963\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIron\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2073\u0026thinsp;\u0026plusmn;\u0026thinsp;35.670\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLead\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.06\u0026thinsp;\u0026plusmn;\u0026thinsp;0.264\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMercury\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \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\u003eRation composition and estimated nutrient values (%, dry matter basis) of the treatments.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIngredient\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTreatment 1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTreatment 2\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTreatment 3\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eTreatment 4\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHominy chop\u003c/p\u003e \u003cp\u003eWheat bran\u003c/p\u003e \u003cp\u003eMolasse meal\u003c/p\u003e \u003cp\u003e\u003cem\u003eEichhorniacrassipes\u003c/em\u003e (WH)\u003c/p\u003e \u003cp\u003e\u003cem\u003eAgrostis curvula\u003c/em\u003e\u003c/p\u003e \u003cp\u003eLucerne\u003c/p\u003e \u003cp\u003eCotton OCM\u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eFeed lime\u003c/p\u003e \u003cp\u003eFeed grade urea\u003c/p\u003e \u003cp\u003eFeed salt\u003c/p\u003e \u003cp\u003ePremix\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e56.6\u003c/p\u003e \u003cp\u003e15\u003c/p\u003e \u003cp\u003e10\u003c/p\u003e \u003cp\u003e0\u003c/p\u003e \u003cp\u003e5\u003c/p\u003e \u003cp\u003e5\u003c/p\u003e \u003cp\u003e5\u003c/p\u003e \u003cp\u003e1.7\u003c/p\u003e \u003cp\u003e1.2\u003c/p\u003e \u003cp\u003e0.5\u003c/p\u003e \u003cp\u003e0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e42.2\u003c/p\u003e \u003cp\u003e5\u003c/p\u003e \u003cp\u003e10\u003c/p\u003e \u003cp\u003e25\u003c/p\u003e \u003cp\u003e5\u003c/p\u003e \u003cp\u003e5\u003c/p\u003e \u003cp\u003e5\u003c/p\u003e \u003cp\u003e1.5\u003c/p\u003e \u003cp\u003e0.8\u003c/p\u003e \u003cp\u003e0.5\u003c/p\u003e \u003cp\u003e0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e37.4\u003c/p\u003e \u003cp\u003e5\u003c/p\u003e \u003cp\u003e10\u003c/p\u003e \u003cp\u003e35\u003c/p\u003e \u003cp\u003e5\u003c/p\u003e \u003cp\u003e0\u003c/p\u003e \u003cp\u003e5\u003c/p\u003e \u003cp\u003e1.5\u003c/p\u003e \u003cp\u003e0.6\u003c/p\u003e \u003cp\u003e0.5\u003c/p\u003e \u003cp\u003e0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e32.5\u003c/p\u003e \u003cp\u003e0\u003c/p\u003e \u003cp\u003e10\u003c/p\u003e \u003cp\u003e45\u003c/p\u003e \u003cp\u003e5\u003c/p\u003e \u003cp\u003e0\u003c/p\u003e \u003cp\u003e5\u003c/p\u003e \u003cp\u003e1.5\u003c/p\u003e \u003cp\u003e0.5\u003c/p\u003e \u003cp\u003e0.5\u003c/p\u003e \u003cp\u003e0.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNutrients\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCrude Protein (%)\u003c/p\u003e \u003cp\u003eEther Extract (%)\u003c/p\u003e \u003cp\u003eCrude Fibre (%)\u003c/p\u003e \u003cp\u003eNeutral Detergent Fibre (%)\u003c/p\u003e \u003cp\u003eGross Energy (MJ/kg DM)\u003c/p\u003e \u003cp\u003eCalcium (Ca %)\u003c/p\u003e \u003cp\u003ePhosphorus (P %)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16.2\u003c/p\u003e \u003cp\u003e5.8\u003c/p\u003e \u003cp\u003e11.3\u003c/p\u003e \u003cp\u003e21.9\u003c/p\u003e \u003cp\u003e18.1\u003c/p\u003e \u003cp\u003e0.9\u003c/p\u003e \u003cp\u003e0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15.8\u003c/p\u003e \u003cp\u003e4.7\u003c/p\u003e \u003cp\u003e14.8\u003c/p\u003e \u003cp\u003e27.2\u003c/p\u003e \u003cp\u003e17.4\u003c/p\u003e \u003cp\u003e1.1\u003c/p\u003e \u003cp\u003e0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e15.5\u003c/p\u003e \u003cp\u003e4.4\u003c/p\u003e \u003cp\u003e15.1\u003c/p\u003e \u003cp\u003e28.9\u003c/p\u003e \u003cp\u003e17.3\u003c/p\u003e \u003cp\u003e1.1\u003c/p\u003e \u003cp\u003e0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e15.4\u003c/p\u003e \u003cp\u003e4.0\u003c/p\u003e \u003cp\u003e16.4\u003c/p\u003e \u003cp\u003e30.8\u003c/p\u003e \u003cp\u003e17.0\u003c/p\u003e \u003cp\u003e1.2\u003c/p\u003e \u003cp\u003e0.6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCopper (Cu, mg/kg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIron (Fe, mg/kg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e562\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e766\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e962\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003csup\u003e1\u003c/sup\u003e Oil cake meal, solvent extruded.\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\u003eAnimal allocation to the 4 treatment diets with graded levels of \u003cem\u003eEichhornia crassipes\u003c/em\u003e\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGender\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTreatment 1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTreatment 2\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTreatment 3\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eTreatment 4\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cb\u003eData collection\u003c/b\u003e.\u003c/p\u003e \u003cp\u003eBody weight was recorded at the start of the trial and subsequently at two-week intervals. Daily feed intake (FI) was calculated as the difference between feed offered and orts. Feeding levels were adjusted based on refusals: a 10% reduction was applied when excessive leftovers occurred, whereas a 10% increase was applied when minimal or no refusals were observed. Average daily gain (ADG) was determined as the change in body weight between weighing periods, and feed conversion ratio (FCR) was calculated as weight gain per unit of feed consumed. Manure consistency was scored daily using a 5-point scale, where 1 represented dry faeces with concentric rings and 5 indicated watery diarrhoea with blood.\u003c/p\u003e \u003cp\u003eAt the end of the feeding period, animals were slaughtered at a Grade D, low-throughput experimental abattoir at ARC-API, Irene (Gauteng Province), following South African Meat Safety Act 40 of 2000 regulations and procedures described by Hoffman (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). Carcass traits and classification scores were recorded immediately prior to evisceration. The presence of liver abscesses was assessed for each animal.\u003c/p\u003e \u003cp\u003eFor heavy metal analysis, meat samples were collected from the \u003cem\u003elongissimus dorsi\u003c/em\u003e muscle between the 12th and 13th ribs. Four or five steers and four heifers per treatment were randomly selected for sampling. Concentrations of iron (Fe), copper (Cu), arsenic (As), cadmium (Cd), and lead (Pb) were analysed in both liver and muscle tissues.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eData analysis.\u003c/h2\u003e \u003cp\u003eData on ADG, feed intake, feed conversion ratio, and heavy metal concentrations were analysed using analysis of variance (ANOVA) under the General Linear Model (GLM) procedure of SAS (2020). Treatment means were separated using Fisher\u0026rsquo;s Least Significant Difference (LSD) test, with significance declared at p\u0026thinsp;\u0026lt;\u0026thinsp;0.05. Manure score data were analysed using the chi-square test.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e shows the chemical composition (proximate, fiber fraction and toxic elements) of the \u003cem\u003eEichhornia crassipes\u003c/em\u003e (water hyacinth), while treatment diets nutritive value is illustrated in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. Although not analysed statistically, the values show that in terms of proximate, crude protein (CP), ether extract (EE) and gross energy (GE) were higher in treatments 1 and 2 compared to their counterparts. Treatments 3 and 4 had higher crude fibre (CF) and neutral detergent fibre (NDF) than other treatments. Minerals (calcium, copper, and iron) increased as level of WH increased, except for phosphorus, which was similar across the treatments.\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\u003eEffect of dried water hyacinth-based diet on growth performance of Bonsmara steers (n\u0026thinsp;=\u0026thinsp;8 or 9).\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" 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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTreatment\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003en\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAverage daily gain\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eFeed intake\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eFeed conversion ratio\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.60\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9.52\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5.98\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.82\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6.07\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7.57\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.70\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.85\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e8.36\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.30\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.44\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e14.28\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSEM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.28\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLSD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\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\u003e0.76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.15\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e-value\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003csup\u003eMeans within a column with different letters in subscript differs significantly (\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.05). LSD \u0026ndash; Least squared difference, SEM \u0026ndash; Standard error of the mean\u003c/sup\u003e\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eEffect of dried WH at different inclusion levels in fattening diets on growth performance of Bonsmara is presented in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e. Feed intake (FI), average daily gain (ADG) and feed conversion ratio (FCR) of the steers differed (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) significantly across the treatments. Average daily gain was significantly higher (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) in treatment 1 and lower (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) in treatment 4 than other treatments. Treatments 2 and 3 showed moderate gains (0.82 and 0.70 kg/day), statistically similar (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05) to each other. Feed intake followed the same trend as (ADG), which was highest (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) in treatment 1 and lowest in treatment 4. Treatment 1 had the lowest (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) FCR, while treatment 4 had the highest FCR value of 14.28.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eEffect of dietary inclusion levels of dried water hyacinth on Bonsmara steers manure (Chi\u003csup\u003e2\u003c/sup\u003e test\u0026thinsp;=\u0026thinsp;0.94).\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=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" 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\"\u003e \u003cp\u003eTMT\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eWeek1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eWeek2\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eWeek3\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eWeek4\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eWeek5\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eWeek6\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.61\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.04\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1.05\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eEffect of water hyacinth-based diets on steers manure is shown in Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e. A scale of 1 to 5 was used to score the manure. Across all treatments, manure scores remained low (between 1.1 and 2.1), indicating firm to slightly soft faeces throughout the feeding period. No diarrhoea (scores\u0026thinsp;\u0026ge;\u0026thinsp;4) was observed in any treatment. In Treatment 1, scores were slightly soft during the first two weeks (1.89 to 2.10) but declined progressively to firmer faeces by Week 6 (1.11). Treatments 2 and 4 showed consistently firm to slightly dry manure (0.89 to 1.64), with the lowest scores occurring from Week 4 onwards. Treatment 3 followed a similar pattern, with initial soft faeces (1.62 to 1.75) that stabilised to firm scores (1.02 to 1.17) thereafter.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAverage weight gain (AWG) of the steers varied significantly among treatments over the 14-week feeding period (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Steers in the treatment 1 consistently showed the highest AWG, with a peak of approximately 3.5 kg/day in week 8. Treatments 2 and 3 showed moderate and relatively stable gains of approximately 0.5 to 1.4 kg/day, with both peaking around weeks 8 to 10. In contrast, steers in treatment 4 had the lowest AWG across all weeks, including a negative gain around week 6.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows feed intake (FI) by steers fed graded levels of water hyacinth-based diets over the 14-week feeding period. Feed intake differed markedly among treatments during the 14-week feeding period. Steers receiving the control diet (treatment 1) consistently recorded the highest FI, increasing from approximately 6.0 kg/day in week 2 to over 11.0 kg/day by week 14. Treatments 2 and 3 showed intermediate and relatively comparable intake patterns, with FI rising from about 4.0 to 4.5 kg/day in week 2 to peaks of 7.5 to 8.0 kg/day in week 14. In contrast, steers fed the highest WH inclusion (45%; Treatment 4) exhibited significantly lower FI across all weeks, starting at approximately 2.5 kg/day in week 2 and reaching only 5.5 kg/day by week 14.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab6\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eEffect of heavy metals in graded levels of dried water hyacinth-based diets on liver and meat samples (wet weight) from Bonsmara steers.\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=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTMT\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCu\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFe\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e% moist\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eAs\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eCd\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003ePb\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e25.56a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21.75a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e71.5b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14.76ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e24.7a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e72.6b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6.882ab\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e39.02a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e73.1b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.897b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31.96a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e75.48a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLSD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e18.96\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e17.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eF-prob\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eSEM\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.293\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eND\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003csup\u003eMeans within a column with different letters in subscript differs significantly (\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.05). LSD \u0026ndash; Least squared difference, SEM \u0026ndash; Standard error of the mean. ND \u0026ndash; Not detected\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eDietary inclusion of dried water hyacinth had no detectable effect on the presence of arsenic (As), cadmium (Cd), or lead (Pb), as all samples tested negative for these elements across treatments (Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). Copper (Cu) significantly differed (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) between T1 vs T3 and T4, Iron (Fe) concentrations did not differ (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05) among treatments, although numerically higher in T3 and to lesser extent in T4. Moisture content was significantly higher (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) in T4 compared to other treatments. Overall, no heavy metal contamination was detected, and mineral levels remained within expected biological ranges regardless of dietary WH level.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab7\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 7\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eEffect of heavy metals on liver and meat samples (wet weight) from Bonsmara steers fed graded levels of dried water hyacinth-based diets regardless of treatment.\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\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCu\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFe\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e%moist\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLiver\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e28.46a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e48.46a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e69.54b\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMuscle\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.77a\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13.1b\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e75.72a\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLSD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e28.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20.929\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eF-prob\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;\u003cb\u003e0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.002\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSEM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.079\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.988\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.124\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003csup\u003eMeans within a column with different letters in subscript differs significantly (\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.05). LSD \u0026ndash; Least squared difference, SEM \u0026ndash; Standard error of the mean. ND \u0026ndash; Not detected\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe collected data for the toxicology (arsenic, cadmium, and lead) was limited and no statistical analysis could be done for liver and meat samples per treatment. Copper concentration and iron concentration was higher (Cu: P\u0026thinsp;=\u0026thinsp;0.05, Fe: P\u0026thinsp;\u0026lt;\u0026thinsp;0.001, Table\u0026nbsp;\u003cspan refid=\"Tab7\" class=\"InternalRef\"\u003e7\u003c/span\u003e) in liver than meat, but moisture content was higher (P\u0026thinsp;=\u0026thinsp;0.002) in meat than in liver.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eUnavailability of quality fodder and shortage of improved fodder or pasture have been identified as major causes for low meat production (Wimalarathne and Perera, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Water hyacinth has been utilized successfully as livestock feed for ruminants, swine, ducks, geese, and fish due to its high crude protein content and progressive growth. With proper inclusion level to the main ration, WH can be a feasible alternative low-quality roughage such as rice straw, legume straw, hay, and grasses. The WH inhabits freshwater bodies such as tanks, canals, marshes, ponds, rivers, and dams. There is a greater opportunity of utilizing this plant to reduce the feed shortage in the South African livestock feed industry. Utilizing WH as livestock feed is another way of controlling the growth of this plant, apart from biological, chemical, and mechanical control methods.\u003c/p\u003e \u003cp\u003eWater hyacinth used in this study was harvested from Hartbeespoort dam. The dam is fed by a few rivers, which are considered highly polluted from human waste and with agricultural affluent (Auchterlonie et al., \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). The chemical composition of WH is shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The percentage of dry matter, crude protein, ash, and gross energy of the WH was 95.91\u0026thinsp;\u0026plusmn;\u0026thinsp;0.20, 16.06\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12, 15.96\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15 and 15.00\u0026thinsp;\u0026plusmn;\u0026thinsp;0.42, respectively. Ndimele et al (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2011\u003c/span\u003e), reported 23\u0026ndash;25% of protein-related matter in dried WH. A study by Men et al. (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2006\u003c/span\u003e) showed that percentage of crude protein and ash content of WH were 18.6\u0026thinsp;\u0026plusmn;\u0026thinsp;0.71 and 16.7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.95, respectively. The fibre fractions of WH in this study were 47.07\u0026thinsp;\u0026plusmn;\u0026thinsp;0.63 for neutral detergent fiber, 26.66\u0026thinsp;\u0026plusmn;\u0026thinsp;0.75 for acid detergent fiber and 6.30\u0026thinsp;\u0026plusmn;\u0026thinsp;0.50 for acid detergent lignin. Crude fibre content of WH was reported by Men et al. (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2006\u003c/span\u003e) as 21.4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.85. A study by Hossain et al. (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2015\u003c/span\u003e), showed that fresh WH had a range of 8.7\u0026ndash;9.8, 10.1\u0026ndash;11.2, 26.1\u0026ndash;27.4, 12.3\u0026ndash;12.4 and 1.1\u0026ndash;1.8 of dry matter, crude protein, crude fibre, ash, and ether extract, respectively. While Men et al. (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2006\u003c/span\u003e) indicated that higher proportion of protein can be found in immature leaves and petioles of the WH than in mature plants, several studies revealed that the chemical composition of the WH varies with season, habitat, and fraction of the weed (Tucker et al., 1981 and Abdelhamid, 1991). Nevertheless, researchers have promoted the use of WH as animal feed as its high water and mineral content, which suggest that the nutritional value may be appropriate for certain animals (Llo et al., 2020). Due to the high levels of cellulose and hemicellulose, Murkherjee and Nandi (2004) recommended the possibility of using WH as feed for ruminants. The minimum amount of crude protein content in fodder for ruminants should be 9%. Now the crude protein contained in either dry or fresh WH is ideal to be utilised for growing cattle feed.\u003c/p\u003e \u003cp\u003eAlthough WH is a good potential for livestock feed owing to its nutrient value, however, the fodder may contain toxic materials from the source of biomass. The heavy metals like cadmium (Cd), lead (Pb), mercury (Hg), and metalloids such as arsenic (As) and fluorine can be absorbed by WH due to greater absorbing capacity (Shi and Zhao, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). This study shows that the tested WH had As, Cd, Copper (Cu), Iron (Fe), Pd and Hg concentration of 0.75, \u0026lt;\u0026thinsp;0.5, 11.0, 2073, 2.06 and \u0026lt;\u0026thinsp;0.1%. When feeding livestock, what is imperative in terms of nutrition and feed safety, is that concentration of the metalloids should not be traceable. If they do, it should not be above the normal threshold.\u003c/p\u003e \u003cp\u003eMaximum tolerable level for copper in cattle feeds is estimated at 40 mg/kg, but results vary (NRC 2016). As indicated by NRC 2016, levels of 5 mg/kg or slightly above seem ideal. Dietary estimated concentration for treatments 2, 3 and 5 are higher than the recommended concentration of 5 mg/kg, but do not reach the maximum (40 mg/kg) concentration (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The calculated Fe concentration in the treatment diets (treatments 2, 3 and 4) were above the maximum tolerable concentrations (500 mg/kg, NRC 2016). The Fe content in the rations increased as WH level increased (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The high Fe concentrations can interfere with Cu absorption and lead to Cu deficiency (Bremner et al., \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e1987\u003c/span\u003e). This Fe interference with Cu can be observed in the decreasing Cu concentration in the liver, whilst Fe concentration increases (Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe present study evaluated the effects of graded levels of dried WH on growth performance, feed utilisation, manure consistency and heavy-metal residues in Bonsmara steers. Overall, the inclusion of WH at 25 to 45% of the diets (treatment 2 to 4) had a clear depressive effect on average daily gain (ADG), feed intake (FI), and feed conversion efficiency/ratio (FCR) (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Steers fed the control diet (treatment) showed performance values consistent with reported growth rates for intensively fed beef weaners (Strydom, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2016\u003c/span\u003e), while WH inclusion progressively reduced ADG, with the lowest gains observed in steers fed treatment 4. This decline aligns with studies indicating that WH has limitations as a major component in ruminant diets due to its high fibre fraction, low energy density, and poor palatability (Masifwa et al., \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2001\u003c/span\u003e; Hossain et al., \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). Reduced FI in the WH diets provides a direct explanation for the poorer growth performance. Low acceptability of WH, likely due to its fibrous structure and potential presence of secondary metabolites, has been noted in previous studies on cattle and buffaloes (Aderibigbe \u0026amp; Brown, \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1993\u003c/span\u003e; Teye et al., 2019). A contributing to the decrease in performance may be the low level of Cu in the liver. Copper levels on a wet weight basis should exceed 25 ppm (Miranda et al., \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2006\u003c/span\u003e). Levels below this will affect performance negatively, and with the increase in Fe (Table\u0026nbsp;\u003cspan refid=\"Tab7\" class=\"InternalRef\"\u003e7\u003c/span\u003e), Cu availability will be depressed further.\u003c/p\u003e \u003cp\u003eAcross the 14-week feeding period, the average weight gain (AWG) patterns further illustrate the negative impact of increasing water hyacinth inclusion on growth performance (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The control group (treatment 1) consistently outperformed all WH-based treatments, showing higher and more stable gains throughout the trial, including a marked peak around Week 8, coinciding with the period of highest feed intake. In contrast, steers on WH diets displayed reduced and more variable AWG, with steers fed treatment 4 experiencing a pronounced drop below zero around week 6, reflecting insufficient nutrient supply relative to growth requirements. Although all WH treatments showed temporary improvements around weeks 8\u0026ndash;10, their gains remained well below the control group, indicating that WH could not sustain optimal growth even when short-term intake was adequate.\u003c/p\u003e \u003cp\u003eFeed intake patterns across the 14-week feeding period further demonstrated a consistent reduction in voluntary FI with each increase in WH inclusion (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). This is consistent with Mahmood et al. (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2018\u003c/span\u003e), who observed similar intake depression in fish diets containing WH leaf meal, suggesting that WH may impart reduced palatability or slower ruminal degradation rates. The reduced intake is likely the major contributing factor to the decreased ADG and the elevated FCRs observed in higher WH treatments (treatments 2 to 4). In ruminants, diets with high structural fibre and low soluble carbohydrate content typically reduce digestible energy intake, which can limit microbial protein synthesis and consequently depress growth (Van Soest, \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e1994\u003c/span\u003e; NRC, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e1996\u003c/span\u003e). Thus, the inferior performance of steers at higher WH inclusion levels is consistent with established rumen physiology.\u003c/p\u003e \u003cp\u003eManure scoring remained within acceptable ranges for all treatments, with no evidence of diarrhoea or digestive disturbances (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). Slightly softer faecal scores in WH treatments during some weeks may reflect differences in fibre digestibility or moisture content of the diets, but the absence of severe changes suggests that WH did not negatively affect gut health. Similar findings were reported by Indulekha et al. (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2019\u003c/span\u003e), who noted stable faecal consistency in goats fed WH-based rations, indicating good ruminal tolerance despite lower intake.\u003c/p\u003e \u003cp\u003eA key concern with WH utilisation in livestock diets is its propensity to accumulate heavy metals, particularly in polluted water systems (Zhou et al., \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2005\u003c/span\u003e; Shi \u0026amp; Zhao, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). However, the present study showed that As, Cd and Pb were not detected in any meat or liver samples, indicating that WH collected from Hartbeespoort Dam did not contribute hazardous residue levels (Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). This is consistent with Ndimele et al. (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2011\u003c/span\u003e), who reported variable but often low heavy-metal accumulation in WH depending on the degree of water contamination. Copper concentrations decreased numerically with higher WH inclusion, but with statistical significance from T1, and were lower for physiological ranges of liver concentration in cattle (Miranda et al., \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2006\u003c/span\u003e). The absence of detectable toxic metals confirms that WH from this source can be used safely at moderate dietary inclusion levels; however, continued monitoring is advisable due to the plant\u0026rsquo;s known ability to bioaccumulate pollutants. The heavy metals of As, Cd and Pb were not detected (\u0026lt;\u0026thinsp;0.02 mg/kg for As, \u0026lt;\u0026thinsp;0.05 mg/kg for Cd and \u0026lt;\u0026thinsp;0.01 mg/kg for Pb) in the samples tested. Furthermore, the daily reference intakes for minerals (for adults) are 14 mg for Fe and 1 mg for Cu (European Commission Regulation (EU) N\u0026ordm; 1169/2011). A portion (100 gram) of meat will provide less than that, whilst liver will provide more than the daily requirement.\u003c/p\u003e \u003cp\u003eCopper and iron concentrations were significantly higher in the liver compared with meat (Table\u0026nbsp;\u003cspan refid=\"Tab7\" class=\"InternalRef\"\u003e7\u003c/span\u003e), which aligns with the well-established role of the liver as the central storage and regulatory organ for trace minerals in ruminants. The liver contained 28.46 mg/kg Cu than the 0.77 mg/kg in meat, reflecting the physiological tendency of hepatocytes to accumulate Cu for metabolic functions including ceruloplasmin synthesis and antioxidant enzyme activity (Suttle, \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). Similarly, Fe concentration was significantly greater in liver (48.46 mg/kg) than in meat samples (13.1 mg/kg), probably because of the liver\u0026rsquo;s function as the primary depot for ferritin and hemosiderin and its role in iron homeostasis and erythropoiesis (McDowell, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2003\u003c/span\u003e). The strong significant difference (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) confirms that tissue type rather than dietary treatment was the main determinant of Fe accumulation (Table\u0026nbsp;\u003cspan refid=\"Tab7\" class=\"InternalRef\"\u003e7\u003c/span\u003e). Moisture content showed the reverse pattern, with meat containing significantly higher moisture (75.72%) than liver (69.54%). This is consistent with the structural and biochemical features of skeletal muscle, which contains abundant myofibrillar proteins that confer high water-binding capacity, resulting in typical moisture levels of 72\u0026ndash;77% in ruminant muscle (Lawrie \u0026amp; Ledward, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2006\u003c/span\u003e).\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eOverall, the findings suggest that dried WH can be used safely as a component of beef cattle diets without risk of heavy-metal contamination, but its nutritional limitations significantly constrain growth performance when included above 25% of the diet. The poor feed intake and low energy contribution at higher inclusion levels undermine its value as a primary feed ingredient. Improving WH utilisation may require treatments that enhance palatability and digestibility such as ensiling, supplementation with energy-rich feeds, or combining with molasses or cassava, which have previously shown promise in ruminant feeding trials (Mukherjee \u0026amp; Nandi, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2004\u003c/span\u003e; Ojeifo et al., \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2000\u003c/span\u003e). Future research should focus on processing methods or feed additives that could improve palatability, adding of a copper source and energy availability to optimise WH inclusion levels for feedlot performance.\u003c/p\u003e"},{"header":"Declarations","content":" \u003cp\u003e \u003cstrong\u003eCompeting interest.\u003c/strong\u003e \u003cp\u003eThe authors have no relevant financial or non-financial interest to disclose.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding.\u003c/h2\u003e \u003cp\u003eOur thanks go to Hya Matla \u0026ndash; URSINIX for their support and supply of cattle and water hyacinth and the support by the ARC-AP in providing feed ingredients, facilities, personnel and veterinary support for this joint effort.\u003c/p\u003e\u003ch2\u003eAuthor contributions.\u003c/h2\u003e \u003cp\u003eKlaas-Jan leeuw contributed to the study design. Material preparation and data collection by Lemohang Makhanya and Klaas-Jan Leeuw. Data was analysed statistically by Nicolene Cochrane. Manuscript preparation and revisions were done by all authors.\u003c/p\u003e\u003ch2\u003eAcknowledgements.\u003c/h2\u003e \u003cp\u003eThe authors would like to thank Mr K W Mashiane, J K Mokgase, P M Seboko and P T Motlaphi for their dedication to the care of the animals used in the trial. The ARC Soil, Water and Climate institute and Nutrilab for sample analysis.\u003c/p\u003e\u003ch2\u003eData availability.\u003c/h2\u003e \u003cp\u003eThe datasets generated and/or analysed during this study are available on request by the corresponding author.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAderibigbe AO, Brown AA (1993) Nutritive characteristics of two tropical aquatic weeds for ruminants. \u003cem\u003eIfe J Agric\u003c/em\u003e 16\u0026ndash;17:42\u0026ndash;54.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAOAC (2006) \u003cem\u003eOfficial methods of analysis\u003c/em\u003e, 18th edn. Association of Official Analytical Chemists, Gaithersburg, MD.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAOAC (2015) \u003cem\u003eOfficial methods of analysis: determination of heavy metals in food by inductively coupled plasma\u0026ndash;mass spectrometry\u003c/em\u003e. AOAC International, Gaithersburg, MD.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAuchterlonie J, Eden CL, Sheridan C (2021) The phytoremediation potential of water hyacinth: a case study from Hartbeespoort Dam, South Africa. \u003cem\u003eS Afr J Chem Eng\u003c/em\u003e 37:31\u0026ndash;36.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBagnall LO, Furman TS, Hentges JF Jr, Nolan WJ, Shirley RL (1973) Feed and fiber from affluent-grown water hyacinth. In: Proceedings of the conference, Oklahoma City, Oklahoma, 5\u0026ndash;7 March 1974.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBalehegn M, Kebreab E, Tolera A, Hunt S, Erickson P, Crane TA, Adesogan AT (2021) Livestock sustainability research in Africa with a focus on the environment. \u003cem\u003eAnim Front\u003c/em\u003e 11(4):47\u0026ndash;56.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBremner, I., Humphries, W. R., Phillippo, M., Walker, M. J., Morrice, P. C. (1987). Iron-induced copper deficiency in calves: dose-response relationships and interactions with molybdenum and sulphur. Animal Production, Volume 45, Issue 3, December 1987, pp. 403\u0026ndash;414.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrendonck L, Maes J, Rommens W, Dekeza N, Nhiwatiwa T, Barson M, Callebaut V, Phiri C, Moreau K, Gratwicke B, Stevens M, Alyn N, Holsters E, Ollevier F, Marshall B (2003). The impact of water hyacinth (Eichhornia crassipes) in a eutrophic subtropical impoundment (Lake Chivero, Zimbabwe). II. Species diversity. \u003cem\u003eArch Hydrobiol\u003c/em\u003e 158(3):389\u0026ndash;405.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCommission Regulation (EU) No 1169/2011 (2011) On the provision of food information to consumers. \u003cem\u003eOff J Eur Union\u003c/em\u003e L304:18.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eErdaw MM (2023) Contribution, prospects and trends of livestock production in sub-Saharan Africa: a review. \u003cem\u003eInt J Agric Sustain\u003c/em\u003e 21(1):2247776.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFouzi MNM, Deepani MLANR (2018) Water hyacinth (Eichhornia crassipes) leaves as an alternative protein source for feeding early phase of Tilapia (Oreochromis niloticus). \u003cem\u003eSri Lanka Vet J\u003c/em\u003e 65(1).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHoffman I (2014) Official slaughter methods in South Africa. \u003cem\u003eStockfarm\u003c/em\u003e June 2014:64\u0026ndash;65.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHossain ME, Sikder H, Kabir MH, Sarma SM (2015) Nutritive value of water hyacinth (Eichhornia crassipes). \u003cem\u003eJ Anim Feed Res\u003c/em\u003e 5(2):40\u0026ndash;44.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIndulekha VP, Thomas CG, Anil KS (2019) Utilization of water hyacinth as livestock feed by ensiling with additives. \u003cem\u003eIndian J Weed Sci\u003c/em\u003e 51(1):67\u0026ndash;71.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJafari N (2010) Ecological and socio-economic utilization of water hyacinth (Eichhornia crassipes Mart Solms). \u003cem\u003eJ Appl Sci Environ Manage\u003c/em\u003e 14(2):43\u0026ndash;49.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLawrie RA, Ledward DA (2006) \u003cem\u003eLawrie\u0026rsquo;s meat science\u003c/em\u003e, 7th edn. Woodhead Publishing, Cambridge.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMahmood S, Khan N, Iqbal KJ, Ashraf M, Khalique A (2018) Evaluation of water hyacinth (Eichhornia crassipes) supplemented diets on the growth, digestibility and histology of grass carp (Ctenopharyngodon idella) fingerlings. \u003cem\u003eJ Appl Anim Res\u003c/em\u003e 46(1):24\u0026ndash;28.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMiranda, M., Cruz, J. M., Lopez-Alonso, M., Benedito, J. L., 2006. Variations in liver and blood copper concentrations in young beef cattle raised in north-west Spain: Associations with breed, sex, age and season. Animal Science 82(02):253\u0026ndash;258.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMasifwa WF, Twongo T, Denny P (2001) The impact of water hyacinth, Eichhornia crassipes (Mart) Solms, on the abundance and diversity of aquatic macroinvertebrates along the shores of northern Lake Victoria, Uganda. \u003cem\u003eHydrobiologia\u003c/em\u003e 452:79\u0026ndash;88.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMcDowell LR (2003) \u003cem\u003eMinerals in animal and human nutrition\u003c/em\u003e, 2nd edn. Elsevier, Amsterdam.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMeat Safety Act (No. 40 of 2000). Republic of South Africa.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMen LT, Yamasaki S, Caldwell JS, Yamada R, Takada R, Taniguchi T (2006) Effect of farm household income levels and rice-based diet or water hyacinth supplementation on growth/cost performances and meat indices of growing and finishing pigs in the Mekong Delta of Vietnam. \u003cem\u003eAnim Sci J\u003c/em\u003e 77(3):320\u0026ndash;329.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMukherjee R, Nandi B (2004) Improvement of in vitro digestibility through biological treatment of water hyacinth biomass by two \u003cem\u003ePleurotus\u003c/em\u003e species. \u003cem\u003eInt Biodeterior Biodegradation\u003c/em\u003e 53(1):7\u0026ndash;12.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNational Academies of Sciences, Engineering and Medicine (2016) \u003cem\u003eNutrient requirements of beef cattle\u003c/em\u003e, 8th rev edn. National Academies Press, Washington, DC.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNdimele PE, Kumolu-Johnson CA, Anetekhai MA (2011) The invasive aquatic macrophyte water hyacinth: problems and prospects. \u003cem\u003eRes J Environ Sci\u003c/em\u003e 5(6):509\u0026ndash;520.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNRC (1996) \u003cem\u003eNutrient requirements of beef cattle\u003c/em\u003e, 7th edn. National Academy Press, Washington, DC.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOjeifo M, Ekokotu PA, Olele NF, Ekelemu JK (2000) A review of the utilisation of water hyacinth control measures for a noxious weed. In: Proceedings of the International Conference on Water Hyacinth, New-Bussa, 27 Oct\u0026ndash;1 Nov 2000, pp 183.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSaha S, Ray AK (2011). Evaluation of nutritive value of water hyacinth (Eichhornia crassipes) leaf meal in compound diets for Rohu, \u003cem\u003eLabeo rohita\u003c/em\u003e fingerlings after fermentation with two bacterial strains isolated from fish gut. Turkish Journal of Fisheries and Aquatic Sciences. 2011; 11:199\u0026ndash;207.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShi G, Zhao Q (2007) Uptake of heavy metals by water hyacinth in polluted waters. \u003cem\u003eJ Environ Sci\u003c/em\u003e 19(8):1055\u0026ndash;1060.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStrydom P (2016) Carcass and meat quality of South African beef under feedlot conditions. \u003cem\u003eS Afr J Anim Sci\u003c/em\u003e 46(4):348\u0026ndash;359.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSuttle NF (2010) \u003cem\u003eMineral nutrition of livestock\u003c/em\u003e, 4th edn. CABI Publishing, Wallingford.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTeye M, Barku VYA, Odoi FNA, Kyereme C (2021a) Composition of water hyacinth (Eichhornia crassipes) harvested from the Volta Lake, Ghana, and its potential as a feed ingredient in rabbit rations. \u003cem\u003eAdv Anim Vet Sci\u003c/em\u003e 9(2):230\u0026ndash;237.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTeye M, Barku VYA, Odoi FNA, Kyereme C (2021b) Water hyacinth (Eichhornia crassipes) meal in rabbit diets: effects on meat quality and heavy metal content. \u003cem\u003eACS Food Sci Technol\u003c/em\u003e 1:1711\u0026ndash;1716.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTham HT (2016) Utilisation of water hyacinth as animal feed. \u003cem\u003eNova J Eng Appl Sci\u003c/em\u003e 4(1):1\u0026ndash;16.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTulu D, Gadissa S, Hundessa F, Kebede E (2023) Contribution of climate-smart forage and fodder production for sustainable livestock production and environment: lessons and challenges from Ethiopia. \u003cem\u003eAdv Agric\u003c/em\u003e 2023.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVan Soest PJ (1994) \u003cem\u003eNutritional ecology of the ruminant\u003c/em\u003e, 2nd edn. Cornell University Press, Ithaca, NY.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWimalarathne HDA, Perera PCD (2019) Potentials of water hyacinth as livestock feed in Sri Lanka. \u003cem\u003eIndian J Weed Sci\u003c/em\u003e 51(2):101\u0026ndash;105.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhou W, Tan L, Liu D, Yan H, Zhao M, Zhu D (2005) Research advances of \u003cem\u003eEichhornia crassipes\u003c/em\u003e and its utilization. \u003cem\u003eJ Huazhong Agric Univ\u003c/em\u003e 24(4):423\u0026ndash;428.\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":"beef cattle, invasive plants, feedlot nutrition, heavy metals, alternative feeds","lastPublishedDoi":"10.21203/rs.3.rs-8697296/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8697296/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eReducing feed costs while maintaining profitable beef production continues to challenge farmers, increasing the need to identify alternative feed resources. \u003cem\u003eEichhornia crassipes\u003c/em\u003e (water hyacinth; WH), an invasive aquatic plant, has potential as a ruminant feed ingredient; however, its ability to accumulate pollutants raises food-safety concerns. This study evaluated the nutritive value of dried WH in iso-nitrogenous feedlot diets and assessed the presence of heavy metals in tissues of cattle consuming WH. Four diets containing 0%, 25%, 35%, or 45% WH were formulated and fed to weaner cattle. Average daily gain decreased significantly with increasing WH inclusion (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001), with cattle in the control group achieving 1.60 kg/day compared with 0.83, 0.70, and 0.30 kg/day in the 25%, 35%, and 45% WH treatments, respectively. Feed intake showed a similar declining pattern, and feed conversion ratio worsened at higher levels of WH inclusion. Heavy metals were not detected in liver or muscle samples, although copper concentrations decreased numerically as dietary WH increased. The absence of detectable heavy metal residues is encouraging; however, routine screening of WH-fed livestock products remains advisable due to the plant\u0026rsquo;s capacity to absorb environmental contaminants. Further research is needed to identify post-drying additives or processing strategies that improve the palatability and intake of WH to enhance its value as a cost-effective feed resource for beef cattle.\u003c/p\u003e","manuscriptTitle":"Effect of dried Eichhornia crassipes (water hyacinth) supplemented diet on growing Bonsmara steers calves.","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-09 18:47:23","doi":"10.21203/rs.3.rs-8697296/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":"50d05116-66b3-4c2f-839e-cdb2cf592f5d","owner":[],"postedDate":"February 9th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-03-12T10:42:46+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-09 18:47:23","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8697296","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8697296","identity":"rs-8697296","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}