Conjugated linoleic acid relieved milk fat depression through modulating gut microbial community composition and function induced by high concentrate diet

High concentrate diet (HCD) fed to ruminants is to meet the increasing requirement for milk. Milk fat, one important nutritional ingredient, is depressed by HCD, namely milk fat depression (MFD). The effects of the profile of ruminal microbiota, the synthesis and transportation of fatty acid and transcriptomics in liver on MFD have not been systematically studied. Conjugated linoleic acid (CLA), a health long chain fatty acid with dual functionality in mitigating inflammation and enhancing fatty acid biosynthesis, was administrated in mice transplanted with rumen microbiota of Hu sheep with SARA by oral gavage. Gut metagenome was conducted to explore the effect of gut microbiota changed by CLA on MFD.