Effects of polyphenolic extract from Eucommia ulmoides Oliver leaf on growth performance, digestibility, rumen fermentation and antioxidant status of fattening lambs.

To investigate the effects of polyphenolic extract from Eucommia ulmoides Oliver leaf (PEEU) on growth performance, digestibility, rumen fermentation and antioxidant status of fattening lambs, 30 weaned male Huzhou lambs were equally divided into three treatments and fed the basal diet supplemented with 0 (CON), 5 (PEEU5) or 10 (PEEU10) g/kg PEEU. Dietary PEEU supplementation did not affect growth performance and apparent digestibility of nutrients. Compared with the CON group, lambs in the PEEU10 group had lower ammonia nitrogen concentration (p < .01) and acetic acid to propionic acid ratio (p < .05) and higher the molar proportion of propionate (p < .05) in rumen fluid. Ammonia nitrogen concentration (p < .01) and the molar proportion of propionate (p < .05) were affected by an interaction between PEEU and sampling day. Dietary PEEU supplementation at 10 g/kg increased total antioxidant capacity (p < .05), superoxide dismutase (p < .05) and glutathione peroxidase (p < .01) activities in serum and glutathione peroxidase activity (p < .05) in liver and decreased (p < .05) malondialdehyde content in serum and liver compared with the CON group. In conclusion, dietary PEEU supplementation affected rumen fermentation patterns and improved antioxidant status of fattening lambs.