Effects of yeast and yeast cell wall on performance and health of newly received beef steers and heifers grazing bahiagrass pastures

The objective of this project was to evaluate the effects of feeding yeast and yeast cell wall (YP) on health and performance of high-risk, newly received beef cattle. Steers and heifers (n = 240, BW = 183.0 ± 1.66 kg) were shipped to White Sand Branch Unit. At arrival, they were assigned randomly to pasture replicates (n = 16), and pasture was randomly assigned to treatment of YP (5 g of Saccharomyces cerevisiae + 5 g of yeast cell wall offered per head daily) or no added yeast or cell wall (CON) via a co-product–based feed while cattle grazed bahiagrass pastures. Feeding YP tended to increase d-56 BW (P = 0.09) and tended to increase ADG from d 0 to 56 (P = 0.10). Supplement DMI did not differ at any time during the study (P < 0.19); however, it was lower than projected, thereby YP intake was lower than targeted 10 g/d (58% of target from d 0–7 and 90.4% from target the first 28 d). No effect of YP was noted on morbidity, or percentage of cattle removed from the study (P ≥ 0.61) or serum antibody production (P = 0.78); however, YP tended (P = 0.08) to increase percentage of animals requiring one treatment and reduced (P = 0.05) second treatment cost. Feeding YP resulted in limited effects on performance and health response; however, the response may have been delayed due to poor intake following arrival in all animals.