The Effects of Dual-Yeast Compound Preparation on the Intestinal Health and Metabolism of Lambs

Microecological preparations exert beneficial effects on the health of young ruminant animals; however, the mechanism is unclear. As a result, the present study analyzed the effects of yeast cultures on the growth properties, microbiome, and metabolism of weaned lambs. In this study, a total of 20 weaned lambs were randomly, stochastically divided into four teams: the control group (Group A) were fed a basic diet; Group B were fed with <i>Saccharomyces cerevisiae</i> BC strain culture (30 g/head/d); Group C were fed with <i>Kluyveromyces marquez</i> XR4 strain culture (30 g/head/d); Group D were fed with a composite culture of the two yeast strains (30 g/head/d). The study lasted for 40 days, with daily records of lamb feed intake and weight. Lamb feces were collected regularly for metagenomic sequencing and metabolomics analysis. The average daily weight gain and average daily yield of Group D lambs were significantly higher than those of Group A lambs (<i>p</i> < 0.01). The feed utilization rate in the yeast-fed groups was considerably higher than in the control group (<i>p</i> < 0.05), indicating that the addition of yeast crops to lamb feed might improve lamb feed performance. <i>Bacteroides</i> and the mTOR signaling pathway were dramatically enriched in the intestines of weaned lambs in the yeast-culture-fed groups, and their expression levels of ketones and benzoic acid compounds were significantly upregulated. These results indicated that yeast culture had excellent effects on weaned lambs in regulating immunological functioning and the intestinal environment, protecting the enteric mucosal barrier, improving digestion and nutritional absorption, and enhancing antioxidant function. In summary, adding yeast culture to weaned lamb feed can generate a positive effect on its productivity performance and gut health. These findings provide novel insights into promoting the health of young ruminants.