Abstract
This review aimed to summarize the relationship between rumen bacteria and production performance in dairy cows. The composition and metabolic functions of rumen bacteria significantly influenced production performance. However, previous studies lacked a systematic review of how variations in rumen bacterial composition correlate with production performance. This review described the differences in rumen bacterial composition among dairy cows with varying production performance, focusing on milk yield and composition, feed efficiency (FE), average daily gain (ADG) and methane production. Additionally, we explored the differences in rumen bacteria across different parities and testing time points. Through this systematic summary, we discussed the impact of rumen bacterial composition on dairy cow production performance and provided new insights and guidelines for devising targeted microbiome adjustment strategies.