The Low Dose of Saccharomyces cerevisiae Is Beneficial for Rumen Fermentation (Both In Vivo and In Vitro) and the Growth Performance of Heat-Stressed Goats.

This study aimed to investigate the effects of on rumen fermentation and the growth performance of heat-stressed goats. The fermentation experiment was conducted using added at 0‱ (HS1), 0.30‱ (SC1), 0.60‱ (SC2), and 1.20‱ (SC3) of the dry matter (DM) weight of the basal diet. The results showed that supplementing with 0.60‱ (SC2) could increase the pH, acetic acid to propionic acid ratio, the concentrations of ammonia nitrogen, total volatile fatty acids, acetic acid, propionic acid, butyric acid, and the degradability of DM, neutral detergent fiber, and acid detergent fiber in rumen fluids of heat-stressed goats. In the feeding experiment, twelve heat-stressed goats were assigned to a 4 × 4 Latin square experimental design, and the supplement levels are similar to the fermentation experiment above. Similar effects on rumen fermentation and digestibility parameters were obtained with a supplement with 0.60‱ of (SC2A) compared to the fermentation trial. Moreover, in the SC2A group, the DM intake and average daily gain also increased significantly compared with other groups. These results suggested that a low dose of can still effectively improve the rumen fermentation and growth performance of heat-stressed goats.