Study On The Structure Of Mammary Microflora In Dairy Cows By High Throughput Sequencing

In order to analyze the structural characteristics of milk cow mammary microflora and the influence of milk cow varieties and soil microflora on the formation of milk cow microflora,this paper selected a total of 24 milk cows from three varieties:Charolet,Simmental and Grassland red bull,collecting milk sample and its breeding environment soil sample respectively,using 16s rRNA genes Illumina HiSeq High-throughput sequencing and bioinformatics methods analyzed the community structure of each sample.The results showed that a total of 256 genera were detected in the milk samples at the taxonomic level of the microbial "genus",and the dominant bacteria were Acinetobacter,Chloroplast-unclassified and Bacillus,with the relative abundance of 11.06%,10.44%and 4.13%,respectively.Among them,76 genera of Charolet variety were detected.The dominant bacteria were Acinetobacter,Chloroplast-unclassified and Bacillus,with the relative abundance of 17.38%,12.16%and 7.57%,respectively.174 genera of Simmental variety were found.The dominant bacteria were Acinetobacter,Chloroplast-unclassified and Aneurinibacillus,and the relative abundance was 11.14%,8.14%and 6.70%,respectively.46 genera of Grassland red bull variety were identified,and the dominant bacteria were Chloroplast-unclassified,Streptomyces and Acinetobacter,with the relative abundance of 29.67%,7.55%and 7,47%,respectively.The dominant bacteria genera and their abundance of milk samples of the three varieties were different,and the similarity of shared bacteria genera was different.A total of 32 genera were detected from soil samples,and the dominant bacteria were Bacillus,Sporosarcina and Ruminococcaceae,with relative abundance of 13.10%,12.89%and 11.00%,respectively.The comparative analysis results of soil samples showed that there were differences in the similarity of the bacteria species among samples from different environments,with the lowest similarity of 5.88%and the highest similarity of 33.33%.The comparison between the milk sample bacteria of each variety of cow and the soil bacteria of the breeding environment of this variety of cow shows that there are also common bacteria genera between them,and the similarity is different.The results of the comparative analysis on the structure of the bacterial flora of each sample showed that the varieties of dairy cow and the environmental bacterial flora had a certain influence on the formation of the mammary microflora of dairy cow studied in this paper,which provided a theoretical basis for the prevention and control measures of dairy cow mastitis.