highly significantp < 0.01
In the correlation analysis between rumen fermentation parameters and rumen microorganisms, Propionic and TVFA showed a significant positive correlation with Prevotella ( p < 0.05), butyric showed a highly significant positive correlation with Prevotella ( p < 0.01), and propionic butyric, and TVFA showed a positive correlation with Bacteroides ( p < 0.05); L-cysteine was significantly positively correlated with Prevotella and Anaeroplasma ( p < 0.05) and Eubaterium in rumen microbial-serum metabolite correlation analysis ( p < 0.01).