Effects of supplementation of vitamin B-complex on performance of beef calves during a 42-day preconditioning program

This study evaluated the effects of supplementation levels of a blend of vitamin B complex offered to weaned beef calves in a 42-day preconditioning program. Sixty-three Angus × Hereford calves were stratified by body weight (BW; 252 ± 3.7 kg) after weaning (d0) and allocated into 21 pens (3 calves/pen). Pens were randomly assigned to one of three treatments: (1) Control, (2) VitB1g, or (3) VitB2g. Calves assigned to vitamin B supplementation received vitamin B complex (1 vs. 2 g/calf daily; Vivalto, Selko USA; containing pantothenic acid [B5], pyridoxine [B6], folic acid [B9], biotin [B7], cyanocobalamin [B12]) mixed with 1.3 kg of dried distillers' grains (DDG), while calves in the Control group received only DDG. All calves had free-choice access to chopped alfalfa-grass hay and limited whole corn. Body weights and blood samples were collected from all calves on days 0, 1, 3, 7, 14, 21, and 42 relative to weaning to evaluate plasma cortisol and acute-phase proteins. Vitamin B7 concentration was measured on days 0, 14 and 42. Pen was the experimental unit, and data were analyzed as repeated measures using the MIXED procedure in SAS. No effects of treatment, day, and the interaction (P ≥ 0.23) were observed for any of the growth performance variables analyzed. At weaning, all calves had similar (P ≥ 0.91) plasma vitamin B7 concentrations, and with two weeks of supplementation, on d14, calves assigned to VitB2g treatment had greater (P ≤ 0.005) vitamin B7 concentration than calves assigned to VitB1g and Control treatments, which had similar vitamin B7 concentrations (P = 0.79). At the end of the preconditioning phase, on d42, calves assigned to VitB2g had greater (P ≤ 0.02) vitamin B7 concentrations than calves assigned to VitB1g and Control treatments, which continued to remain similar (P = 0.17). A tendency for a treatment × day (P = 0.08) for cortisol concentration was observed. Cortisol concentrations were similar at weaning (P ≥ 0.89). Interestingly, at the end of the supplementation, calves supplemented with vitamin B complex, regardless of vitamin level supplementation, had lower cortisol concentration (P ≤ 0.05) than calves assigned to the Control treatment. Collectively, these findings suggest that vitamin B complex supplementation during preconditioning enhances circulating vitamin B7 concentration, especially at 2 g/d, and may attenuate physiological stress responses in weaned beef calves.