Effects of Timing of Injectable Trace Mineral Administration on Beef Calf Performance and Health Following Simulated Marketing

The objective of this study was to evaluate the effects of timing of injectable trace mineral (ITM) administration (28 days (d) prior to or at weaning) on performance and health in mixed-sex beef calves (n = 115; 224 ± 40 kg). Calves were randomly assigned to one of the following treatments: (1) no ITM (CON), (2) ITM administered 28 d before weaning (PW), or (3) ITM administration at weaning (WEAN). At weaning, calves were transported to a local auction barn, held overnight, and returned the following day; BW, blood, and hair samples were collected prior to and through the receiving period. Data were analyzed using SAS 9.4. Serum Se increased in PW calves following ITM administration (p < 0.01). Serum Mn increased in PW and WEAN groups (p < 0.01) and PW calves showed increased serum Cu at weaning (p < 0.01). Across treatments, calves experienced 6% shrink following weaning and transport, with recovery of BW and intake occurring within 21 d and 8 d, respectively. Despite improved mineral status, no performance benefits were observed during the receiving period, reflecting adequate baseline mineral status and low-stress management conditions, suggesting that ITMs may have limited benefits in well-managed herds.