Maternal Tributyrin Supplementation During the Perinatal Period Is Associated with Improved Ewe Milk Quality and Lamb Growth Performance, Immunity, and Antioxidant Status.

This study investigated the effects of tributyrin supplementation on the immune and antioxidant status of lambs born to perinatal Hu ewes with negative energy balance (NEB) at 75%. Twenty healthy Hu ewes (average body weight 45.00 ± 5.00 kg) with similar body condition score, pregnant for 100 days with twin lambs, were randomly allocated into two groups: NEB group and 0.5% tributyrin supplementation group (TB). Lambs were artificially fed with milk from their respective maternal groups for 42 days and were classified as L-NEB (n = 20) and L-TB (n = 20). The experimental period lasted from 40 days before delivery to 42 days after delivery. At 42 days of age, five male lambs from each group were randomly selected and euthanized for analysis. Tributyrin supplementation significantly increased fat-corrected milk yield, milk fat content, and colostrum fat yield in perinatal ewes (p < 0.01). Lambs in the L-TB group exhibited improved growth performance compared with L-NEB lambs (p < 0.05). Serum triglyceride concentration at 7 days of age was 68.4% higher, and serum triglyceride and glucose concentrations at 42 days of age were 42.9% and 13.9% higher, respectively, in the L-TB group than in the L-NEB group (p < 0.05). In addition, the L-TB group showed a 39.2% lower serum IL-1β concentration at 7 days and significantly downregulated hepatic IL-8 mRNA expression at 42 days, together with enhanced antioxidant capacity (p < 0.05). These findings suggest that dietary tributyrin supplementation at 0.5% in perinatal undernourished ewes, applied under a controlled NEB feeding regimen, may improve milk composition and, consequently, enhance growth performance, immune status, and antioxidant capacity in lambs.