Eucommia ulmoides leaves improving growth by regulating the rumen microbiome in sheep

BACKGROUND: Ruminants have the ability to convert agricultural byproducts into valuable resources. However, the influence of functional roughage with medicinal value on production performance and rumen function in ruminants remains unclear. This study aimed to examine the role of Eucommia ulmoides leaves (EUL) in the growth performance and rumen microbiome of sheep. RESULTS: Twenty-one healthy female sheep were randomly divided into three groups, in which the EUL feeding amounts were 0% (CON), 5% (Diet 1), and 10% (Diet 2) on a dry matter basis. The results revealed that body weight gain, dry matter intake, and feed conversion efficiency were significantly greater in the Diet 1 group than in the CON and Diet 2 group. The metatranscriptome annotation results indicated that feeding EUL to sheep altered the rumen microbial community. Compared with those in the other two groups, the abundances of butyrate-producing bacteria, such as Coprobacillus, significantly increased in the Diet 1 group. Functional enrichment analysis of the metatranscriptome indicated higher metabolic activity in the carbohydrate and amino acid pathways in the Diet 1 group than in the control group, which might be due to improved nutrient utilization in the Diet 1 group. CONCLUSIONS: In conclusion, feeding 5% EUL to sheep enhanced production performance, feed conversion efficiency, and microbial metabolism. These findings suggest that EUL plays a critical role in sustainable livestock farming as a promising functional roughage.