Effect of injectable trace mineral administration on health, performance, and vaccine response of newly received feedlot cattle

Previous research has established that trace minerals are necessary for optimal growth and immunity, yet challenges exist with intake of dietary trace minerals in cattle newly received at feedlots. A total of 128 crossbred beef bull (n = 40) and steer (n = 88) calves were used for this 42-d receiving study. Cattle were stratified by initial BW (275 ± 9.54 kg) and sex (steer or bull) and then assigned equivalently to treatment pens (n = 8 per treatment). Treatments were (1) negative control (CON) or (2) injectable trace mineral solution containing 60 mg of Zn/mL (as Zn disodium EDTA), 10 mg of Mn/mL (as Mn disodium EDTA), 5 mg of Se/mL (as sodium selenite), and 15 mg of Cu/mL (as Cu disodium EDTA) administered s.c. at 2.2 mL/100 kg of BW on d 0 (ITM). Health was monitored daily by trained personnel blinded to treatment pen assignment. Blood samples and BW were obtained on d 0, 14, 28, and 42 to determine bovine viral diarrhea virus (BVDV) type 1a antibody titer and gain performance. Standard processing procedures were applied on d 0, including administration of a respiratory vaccine containing modified-live BVDV antigens. No difference in overall ADG (P = 0.21) was detected between CON (1.36) and ITM (1.25 kg/d) steers. Overall DMI was not different (P = 0.83) between CON (6.98) and ITM (7.02 kg/d), but G:F tended (P = 0.08) to be less for ITM from d 28 to 42. The morbidity rate observed in this study was low (14% average), and there was no difference (P = 0.71) in morbidity between treatments, which averaged 15.6 and 12.5% for CON and ITM, respectively. There was a treatment × d interaction (P = 0.09) for BVDV-specific antibody titer. On d 14, ITM had a greater (P = 0.02) BVDV antibody titer than CON. These data suggest that ITM did not improve performance or morbidity when the incidence was low; however, the BVDV-specific antibody response to a respiratory vaccine was greater for ITM on d 14.