Effects of Trace Mineral Supplementation on Cow-Calf Performance, Reproduction, and Immune Function

Three-hundred Angus cows were used in a randomized design to evaluate trace mineral supplementation over a 209-d trial on cow and calf performance, liver trace mineral content, and immune function. Treatments included the following supplemental trace minerals: 1) inorganic trace minerals—low level; 2) inorganic trace minerals—high level; and 3) organic trace minerals—high level. Cows fed the high level of inorganic trace minerals lost more weight (P<0.05) than cows fed the other treatments. Cow condition score was not affected by treatment. Calf average daily gain on the organic high level of trace minerals was higher (P<0.05) from birth to May 13 and May 13 to September 24 compared with the other treatments. Pregnancy rate to artificial insemination was higher (P<0.05) when cows were fed the organic high level of trace minerals compared with the other treatments. Trace mineral supplementation had an equivocal impact on liver trace minerals over time. Cell-mediated immune function was not affected by type or level of trace mineral supplementation.