<div>Background: Presently, our understanding of the rumen of Gayals is still very shallow, which is recognized as the most effective and developed fiber degradation system in nature, with abundant microorganisms. Molecular biology technology is an effective means to study the microbial resources in the rumen.&nbsp; 
 
Methods: Rumen contents of 3 Gayals (Gayals, Bos frontalis; G) and 3 Yellow Cattle (Yunnan Yellow Cattle, Bos taurus; Y) were collected in this study. Rumen microbial proteins were extracted by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS), then to analyze the bioinformatics of protein abundance was performed through the bovine rumen transcriptome database (gene.uniGeneset.fasta).&nbsp; 
 
Result: The results were as follows: the differences in protein abundance of Gayals rumen bacteria in Firmicutes, Actinobacteria, Ruminococcus and Olsenella were significantly higher than Yellow cattle (P&lt;0.05) and the difference in protein abundance of Chytridiomycota and Batrachochytrium in rumen fungus of Gayals was significantly less than that of Yellow cattle. Enrichment analysis by KEGG metabolism pathway of differentially expressed proteins in rumen microorganisms was performed, Gayals have higher abundance of &beta;-glucosidase and 6-phosphate-&beta;-glucosidase than Yellow Cattle.</div>

Analysis of Rumen Microbial Protein Abundance of Gayals based on Metaproteomics