Study of Correlation between Milk Yield and Intestinal Microbes in Chinese Holstein Cows under the Same Diet

Abstract

The purpose of this study is to characterize and compare the gut microbes in six Chinese Holstein cows (CHC1, CHC2, CHC3, CHC4, CHC5, CHC6) under the same diet but different milk yields. High-throughput sequencing analysis was used to reveal and compare bacterial communities in faeces. The results showed 13 phyla in the six samples and the most dominant phylum was Firmicutes (approximately accounts for 71% OTUs), in which 18% OTUs were affiliated with Ruminococcaceae. Bacteroidetes was the subdominant phylum, which contributed to 17.5% of the total OTUs. While the majority of the bacterial genera found were unclassified, Solibacillus and Acinetbacter were the first and second predominant genera. Among the cases, the diversity and abundance of gut microbes in the Chinese Holstein cows have no significant difference under the same diet, which suggests that the relationship between milk yield and gut microbes is stable. The factors related to milk yield were calculated with spearman's rank (p<0.05), the results showed that milk yield is significantly associated with age (P=0.029) and body length (P=0.021) of Chinese Holstein cows. By LEfSe analysis (LDA threshold of 2), screening out microorganisms with significant differences in the gut of different milking Chinese Holstein cows. For the reluts, Lachnospiraceae, Mollicutes, Tenericutes Mollicutes, Tenericutes apparently enriched in HMY, but only Fibrobacteraceae apparently enriched in LMY. This indicates microbes play an important role in the milk production of dairy Chinese Holstein cows.