Fig. 5

Results of rumen metabolites analysis (n = 5). A The ruminal differential metabolites as affected by Leu. B Principal component analysis (OPLS-DA) of rumen metabolites. C The Top 30 rumen differential metabolites by KEGG compound database (CON/Leu, variable importance in the projection [VIP] > 1.5, P < 0.05). D Metabolic pathways were analyzed based on different metabolites (Impact > 0.2, P < 0.05). The differences are represented by the color of the group, “CON” means basal diet group; “Leu” means basal diet supplementation with 6.0 g L-Leu/100 kg BW/d group