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

Abstract

<h2>ABSTRACT</h2> 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 ± 12kg 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.