Effects of direct-fed microbial supplementation on feedlot lamb growth performance, serum biochemical markers, fecal consistency, and fecal microbiota

Lay Summary

Transitioning young lambs from milk or forage to a grain-based feedlot diet can be stressful and may slow growth, upset digestion, and affect overall health. This study explored whether giving lambs a probiotic supplement, a mixture of beneficial bacteria designed to support gut health, would help them adjust to this change. Seventy-two lambs were divided into two groups: one group received the probiotic daily for two months, while the other group received none. The lambs that received probiotics showed no difference in growth or feed use while on the supplement. Fecal consistency improved in both groups, suggesting that all lambs adjusted to the high-grain diet. Blood tests and gut bacteria analysis showed natural changes as the lambs developed, with some differences linked to the probiotic. These findings suggest that probiotics may alter gut bacteria, offering a potential strategy to improve feedlot transitions.