Growth Performance, Apparent Digestibility, Serum Indices, and Fecal Bacterial Community Diversity in Yanbian Cattle Fed Diets With Fermented Spent Mushroom Substrate From <i>Pleurotus Eryngii</i> Instead of Brewers Spent Grain

This experiment was to evaluate the effect of fermented spent mushroom substrate from Pleurotus eryngii (FSMPE) instead of brewers spent grain (BSG) on growth performance, apparent digestibility, serum indices, and fecal bacterial community of Yanbian cattle. Thirty heifers were randomly divided into three groups: T0 group (control group, fed a diet without FSMPE); T1 group (fed a diet with FSMPE instead of 50% BSG); T2 group (fed a diet with FSMPE instead of 100% BSG). The results showed that replacing BSG with FSMPE increased nutrient intake (except ether extract), average daily gain and economic efficiency, among which T1 group had the best effect. The apparent digestibility of dry matter, organic matter, crude protein, and neutral detergent fiber in the T1 group was not affected by FSMPE, but decreased significantly in the T2 group. In addition, FSMPE instead of BSG improved the serum biochemical and antioxidant indices of cattle. Meanwhile, FSMPE not only had no adverse effects on the bacterial diversity, but also improved the abundance of certain cellulose-degrading bacteria and potentially probiotic bacteria in rectal feces. These findings showed that replacing 50% BSG with FSMPE had positive effects on growth performance, economic efficiency, and health status of Yanbian cattle.