Rumen Flora Structure And Its Function Prediction Of Different Breeds Of Beef Cattle

In order to systematically explore the rumen microbial diversity and function of different breeds of beef cattle,this experiment uses 16S rRNA gene high-throughput sequencing technology to detect and analyze the bacterial structure of rumen fluid samples from grassland red cattle,Chinese Simmental cattle,and Angus cattle,and to predict its PICRUSt function.The results show that:Prairie Red Bull is based on the composition of the door,Firmicutes and Bacteroidetes are the dominant bacteria,The proportions are 54.15%and 37.34%respectively;Based on the composition of the genus,it is Prevotella₁:9.01%,Rikenellaceae_RC9_gut_group:8.19%,Ruminococcaceae_UCG-005:7.37%,norank f Bacteroidales BS11_gut_group:5.19%,etc.;The PICRUSt function prediction results of the 16S rRNA genome show that the function of microbial flora in the rumen is mainly concentrated on the related genes of amino acid transport and metabolism,carbohydrate transport and metabolism,It indicated that the grassland red cattle may be rich in protein degradation,transport and metabolic enzyme related genes and a large number of cellulose and lignin degrading enzyme genes.The gate-based composition of Chinese Simmental cattle,Firmicutes and Bacteroidetes,are the dominant bacterial groups,the proportions are 62.46%and 22.45%;based on the composition of the genus,they are[Eubacterium]_coprostanoligenes_group:9.16%,Ruminococcus₂:7.90%,norank_fBacteroidales RF16_group:6.23%,norank_fRuminococcaceae:4.79%,Rikenellaceae_RC9_gut_group:4.72%,Ruminococcus₁:4.43%,Prevotella₁:3.73%,etc.;The PICRUSt function prediction of the 16S rRNA genome found that the rumen flora mainly concentrated on carbohydrate transport and metabolism,indicating that Chinese Simmental cattle contain a large amount of cellulose and lignin degrading enzyme genes.Angus cattle have a total of 346 OUTs.After taxonomic identification,they belong to 13 phyla,21 classes,24 orders,40 families,and 123 genera.Bacteroidetes 43.16%and Firmicutes 36.29%were the dominant flora.Based on the genus composition,they are Prevotella₇:29.28%,Succinivibrionaceae_UCG-001:11.30%,Succiniclasticum:1 1.10%,Prevotella₁:6.65%,Ruminococcus₁:5.17%,Succinivibrio:2.75%,etc.;16S function prediction and comparison of COG and KEGG metabolic pathway databases found that the function is concentrated on genes related to amino acid transport and metabolism,carbohydrate transport and metabolism,and may be rich in proteolytic,transport and metabolic enzyme-related genes and a large amount of cellulose and Lignin-degrading enzyme gene.The comparison of the carbohydrate active enzyme（CAZymes）annotation and the KEGG metabolizing enzyme database showed that the predicted functional genes accounted for a higher proportion of glycoside hydrolase and glycosyltransferase;the abundance of acetic acid and butyrate-related enzyme genes was higher.In summary,the high-throughput sequencing technology based on the 16S rRNA gene comprehensively revealed the diversity of the rumen flora of grassland red cattle,Chinese Simmental cattle,and Angus cattle,and it is predicted that it may be rich in protein decomposition,lignocellulose degradation,and volatile fatty acid generating bacteria and enzyme systems,indicating that the three beef cattle should have the advantages of roughage resistance,strong adaptability and high digestibility;It lays a theoretical foundation for demonstrating the diversity of rumen microorganisms,discovering and screening new functional enzyme genes,and also provides a reference for mining other rumen microorganism functional genes related to important nutritional physiological functions.