Prophylactic Feeding of Clostridium butyricum and Saccharomyces cerevisiae Were Advantageous in Resisting the Adverse Effects of Heat Stress on Rumen Fermentation and Growth Performance in Goats

Abstract

This study aimed to investigate the effect of the prophylactic feeding of Clostridium butyricum (CB), Saccharomyces cerevisiae (SC), and their mixture before the onset of heat stress on the rumen fermentation and growth performance of goats, and subsequently, on heat stress status. Forty-eight male Macheng Black × Boer crossed goats (22.25 ± 4.26 kg) were divided into four groups—the control group (fed the basal diet), and the CB (0.05% CB added to the basal diet), SC (0.60% SC added to the basal diet), and Mix (0.05% CB and 0.60% SC added to the basal diet) groups—and fed for fourteen days. Then, these goats were kept in a heat stress environment (with a temperature–humidity index of 87.04) for fourteen days. Then, the parameters of rumen fermentation and growth performance were measured. The results showed that the pH values, the activities of cellulolytic enzymes (avicelase, CMCaes, cellobiase, and xylanase), and the concentrations of ammonia-N, total volatile fatty acid, acetic acid, propionic acid, and butyric acid were significantly increased (p < 0.05) in the rumens of the CB, SC, and Mix groups compared to those of the control group. Moreover, the average daily gain and the digestibility of dry matter, neutral detergent fiber, and acid detergent fiber were significantly increased (p < 0.05) in the CB, SC, and Mix groups compared to those of the control group. These results suggest that these two probiotics and their mixture effectively alleviate the adverse effects of heat stress on rumen fermentation and growth performance via prophylactic feeding.

Yeast Culture Is Beneficial for Improving the Rumen Fermentation and Promoting the Growth Performance of Goats in Summer

“…The rumen pH significantly decreases when goats are exposed to high temperatures in the summer due to changes in physiological activities [9]. Studies have shown that supplementing Saccharomyces cerevisiae or a mixture of Saccharomyces cerevisiae and Clostridium butyricum to the diet of heat-stressed goats can significantly increase the ruminal pH [5,[18][19][20]. In this study, yeast culture supplementation can also increase the goats' rumen pH in a hot summer.…”

“…It is because yeast culture mainly promotes the growth of lactic acid utilization bacteria by changing the structure of the microbial flora in the rumen, so that lactic acid produced in the rumen can be utilized and the rumen pH can be increased to promote rumen fermentation [21,42,44]. The supplementation with yeast or yeast culture can increase the concentration of acetic acid, propionic acid, butyric acid, and total SCFA and reduce the ratio of acetic acid to propionic acid [5,[18][19][20]44]. This present study showed that the rumen pH and SCFA production increased significantly after yeast culture supplemented the goats' diet in the hot summer.…”

“…As described by Zhang et al [33], the DM, NDF, and ADF of the feed, fermentation broth, and fecal samples were analyzed. The digestibility of the DM, NDF, and ADF was calculated as follows [18]: (DM content in feedstuff-DM content in feces or fermentation broth)/DM content in feedstuff × 100 = DM digestibility (%); (NDF or ADF content in feedstuff-NDF or ADF content in feces or fermentation broth)/NDF or ADF content in feedstuff × 100 = NDF or ADF digestibility (%).…”

“…In high temperatures and in high-humidity climates in the summer, yeast can effectively alleviate the adverse effects of heat stress on rumen fermentation and the growth performance of goats [5,14,[18][19][20]. Yeast culture is rich in amino acids, small molecular peptides, oligosaccharides, vitamins, minerals, digestive enzymes, and growth-promoting factors [21].…”