Effect of fermented total mixed rations on rumen microbial communities and serum metabolites in lambs

Background

Diet regulates rumen microbiota, which in turn affects animal health. The present study evaluated the response of rumen microbiota and the immune system of lambs to a fermented total mixed ration diet.

Methods

A total of 30 lambs were assigned into two groups: a group fed an unfermented high-fiber diet (total mixed ration [TMR]) and a group fed an fermented low-fiber diet (fermented TMR [FTMR]).

Results

The results showed that FTMR markedly (p < 0.05) increased average daily gain and dry matter intake compared to TMR. The FTMR diet increased the relative abundance of Veillonellaceae_UCG-001 and decreased the diversity of undesirable microbiota despite stable overall microbial community diversity. Serum metabolomic analysis combined with enrichment analysis showed that serum metabolites were affected by the FTMR and metabolic pathways, and the FTMR diet significantly (p < 0.05) influenced amino acid metabolism of lambs. There was a decrease in inflammatory factors in the FTMR treatment, indicating that inflammatory factors followed the same trajectory as changes in microbial community structure and function.

Conclusions

Overall, the FTMR diet reduced undesirable microbiota diversity, thereby regulating host amino acid metabolism and improving immune status.