Effect of feeding a combination of zinc, manganese and copper amino acid complexes, and cobalt glucoheptonate on performance of early lactation high producing dairy cows

This study determined the effect of feeding a combination of zinc amino acid (AA), manganese AA and copper AA complexes, and cobalt glucoheptonate on productive and reproductive performance of early lactation high producing dairy cows. The product used as a source of the organic trace mineral complexes was Availa4® (Zinpro Corp., Eden Prairie, MN). Forty pregnant Holstein cows were blocked and randomly assigned to one of two dietary treatments at calving. After 48±30 days, cows were moved from the fresh groups to the high production groups within their treatment assignments. Cows were housed in a free-stall barn and group-fed total mixed rations (TMR) containing inorganic minerals (control) or inorganic minerals and Availa4® (Availa4) for 80 days, or until first breeding service. The TMR were formulated to exceed NRC (1988) trace mineral requirements for lactating dairy cows. The Availa4 TMR was formulated to supply each cow with 7 g per day of Availa4® by partially substituting the inorganic minerals in the concentrate mix of the control TMR. Each 7 g of Availa4® supplied 360 mg of zinc, 200 mg of manganese, 125 mg of copper, and 12 mg of cobalt. Cows fed the Availa4 TMR tended to have fewer days to first service (P=0.071), fewer services per conception (P=0.069), and fewer days to conception (P=0.012) as compared to cows fed with the control TMR. Feeding a combination of zinc AA, manganese AA and copper AA complexes, and cobalt glucoheptonate to early lactation Holstein cows improved conception rate with fewer days in milk to pregnancy but had no effect on milk production, milk fat and protein content, linear somatic cell count, animal body condition score, or lameness score.