Revealing the impact of left displacement of the abomasum on fecal microbes of dairy cows by 16S rDNA amplicon sequencing technology

Abstract:

[Objective] Our study aims to measure the changes of microbial flora in feces of healthy postpartum cows and cows suffering from left displacement of the abomasum (LDA), so as to explore the relevance between LDA occurrence and the flora, and assess its potential impact on body metabolism. [Methods] We used 16S rDNA High-Throughput Sequencing technology to determine the 16S rDNA V3-V4 region sequence of microorganisms in the feces of 10 healthy cows and 10 cows with LDA. [Results] The diversity analysis indicated that there were significant differences in microbial diversity and community composition between healthy group and LDA group, and the fecal microbes of the LDA cows had higher species abundance and population differences. The analysis of the top 10 species with the largest abundance at the level of phyla, family, and genus showed that the abundances of Verrucomicrobia, Cyanobacteria, Proteobacteria, Fusobacteria, Bacteroides, p-2534-18B5, Mogibacteriaceae, Fusobacteriaceae, Oscillospira, 5-7N15 and Faecococcus in LDA cows increasedsignificantly (P<0.05), while the abundances of Spirochetes, TM7, Ruminococcaceae, Rikenellaceae and Treponema decreased significantly (P<0.05). Functional prediction analysis showed that the functional genes related to carbohydrate metabolism and lipid metabolism pathway in cows with LDA were greatly up-regulated, while those related to genetic information processing were significantly down regulated. [Conclusion] Our findings confirm that the changes of fecal microorganisms in dairy cows before and after LDA, and provide a foundation for a deeper understanding of the pathogenesis and early diagnosis of LDA.

Key words:dairy cows;LDA;fecal microorganisms;16S rDNA high-throughput sequencing