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

Lay Summary The sudden separation of weaning causes stress, reducing feed intake, increasing cortisol, weakening immunity, and limiting growth of calves. Preconditioning programs aim to reduce these effects by preparing calves for the next production. While mineral supplementation is common practice during preconditioning, vitamin supplementation is less studied in this context. Vitamins are essential for physiological functions and B-complex vitamins are involved in carbohydrate, energy, protein, and amino acid metabolism. Mature ruminants rely on rumen microorganisms to synthesize B-vitamins, but stress and feed quality can limit this capacity, which can be exacerbated in growing cattle. Thus, this study evaluated different levels of B-complex vitamin supplementation on performance and blood parameters of growing calves during a 42-day preconditioning program. Vitamin supplementation increased plasma vitamin B7 concentrations and reduced plasma cortisol by the end of the preconditioning program, but did not affect acute phase proteins, feed intake, or growth performance. These results suggest the potential benefit of B-complex vitamin supplementation in stress reduction, but further research is needed to clarify the role of B-complex vitamin supplementation on the growth of preconditioning beef calves.