CASE STUDY: Supplementation of Chelated Forms of Zinc, Copper, and Manganese to Feedlot Cattle with Access to Drinking Water with High Sulfate Concentration

The objective of this experiment was to evaluate the effects of supplementing a blend of chelated Zn-(2-hydroxy-4-methylthio butanoic acid; HMTBA)2, Cu-(HMTBA)2, and Mn-(HMTBA)2 to feedlot cattle with access to drinking well water that contains high levels of sulfate (1,646 mg/kg). A total of 640 weaned calves with an average BW of 192 ± 12 kg were allocated to 4 pens per treatment in a randomized complete block design and fed a control diet or a diet supplemented with 37, 17.5, and 15.2 mg/kg of Zn from Zn-(HMTBA)2, Cu from Cu-(HMTBA)2, and Mn from Mn-(HMTBA)2, respectively, for the entire feedlot period (267 d). Average daily gain, feed intake and gain to feed ratio were not affected by treatment. However, cattle fed Zn-(HMTBA)2, Cu-(HMTBA)2, and Mn-(HMTBA)2 exhibited less mortality (4.7 vs. 2.44%; P = 0.05) and morbidity (47.1 vs. 37.8%; P = 0.06). Carcass quality was improved by reducing the dark-cutting carcasses from 3.59 to 0.77% (P = 0.02) and fat deposition from kidney, pelvic, and heart area (P = 0.05). From this study, we concluded that supplementation of Zn-(HMTBA)2, Cu-(HMTBA)2, and Mn-(HMTBA)2 to feedlot cattle with access to water with high sulfate concentration improved health and carcass quality. The net economic improvement of adding Zn-(HMTBA)2, C-(HMTBA)2, and Mn-(HMTBA)2 to feedlot cattle diets represented $17.96 per head savings in cattle health and carcass performance when compared with controls.