Evaluation of two-stage weaning and trace mineral injection on receiving cattle growth, behavior, and health

The objective was to evaluate effects of two-stage weaning and trace mineral injection on receiving cattle growth, behavior, and health. Two hundred ninety nine (163 heifers and 136 steers) Angus and Simmental × Angus calves were utilized in a 2 × 2 factorial design. Calves were blocked by location and sex, and assigned to one of four treatments: 1) two-stage weaning and Multimin 90 (MULTIMIN USA, Fort Collins, CO) injection (2MM); 2) two-stage weaning and saline injection (2SAL); 3) abrupt weaning and Multimin injection (AbtMM); 4) abrupt weaning and saline injection (AbtSAL). On d -6, calves were weighed, inserted with Plastic Calf Weaner (Agri-Pro Enterprises of Iowa, Inc., Iowa Falls, IA) devices, received either Multimin 1ml/45.4kg BW) or saline (1ml/45.4kg BW) injections, and bled for plasma cortisol analysis. On d 0, calves were weighed, Plastic Calf Weaner devices were removed, and calves were shipped 272 km to Urbana, IL. Upon arrival, calves were weighed again and steer calves were bled for plasma cortisol analysis. All calves were weighed again on d 14, 28, 41, and 42. Additionally, steer calves were weighed on d 123 and 124. Steers were observed for behavior for the 2d following separation from the dam and checked daily for morbidity by the farm staff. There was no overall effect (P ≥ 0.23) of treatment on steer body weight. Two-stage weaning decreased (P = 0.01) the percentage of BW shrink during shipping. There was no effect (P ≥ 0.14) of weaning strategy or Multimin injection on overall steer ADG, however, 2MM steers tended (P = 0.09) to have an overall increased ADG compared to other treatment combinations. In the two weeks after separation, two-stage weaned calves had increased ADG (P = 0.001). There was an observed interaction (P < 0.01) on overall DMI where 2MM steers were increased compared to 2SAL but not different from AbtMM nor AbtSAL. There was an observed interaction (P = 0.05) on feed efficiency, where 2SAL steers were the most efficient. There was no effect (P ≥ 0.23) of treatment on cortisol levels. Two-stage weaning decreased (P ≤ 0.02) the percentage of calves walking, standing, and vocalizing and increased (P ≤ 0.02) the percentage of calves lying and eating. There was no effect (P ≥ 0.22) of Multimin on any behavioral category. Two-stage weaning had no effect on overall growth, performance, or cortisol but decreased behavioral signs of stress. Multimin had no effect on calf BW, cortisol level, or behavior, but increased DMI in two-stage calves and tended to increase overall ADG