Abstract:

In order to understand the differences of soil bacterial flora structure in different groups of Holstein dairy cows, soil samples were collected from different groups of cow barns in a large-scale Holstein dairy farm in Ningxia, and the bacterial flora structure was determined by 16S rDNA sequencing. The results showed that there was no significant difference between OTU number and Alpha diversity of soil bacterial flora in different groups of cow barns (P>0.05). The results of principal coordinate analysis (PCoA) showed that there were obviously differences in Beta diversity of soil bacterial flora in different groups of cow barns, and the structure of bacterial flora in the soil of high-yielding lactating cow barns was similar to that of low-yielding lactating cow barns. The dominant bacteria (relative abundance>10%) at phylum level in different groups of cow barn soil were Proteobacteria, Bacteroidetes, Actinobacteria and Firmicutes. The abundance of Actinobacteria in lactating cow barn soil was significantly higher than that in other groups (P<0.05). The abundance of Tenericutes and Gemmatimonadates in pre-weaned calf hutch soil was significantly higher than that in other groups (P<0. 01). The dominant bacteria (relative abundance>3%) in the soil of different groups of cow barns were obviously different at the genus level. Among these dominant bacteria, protein-degrading bacteria such as Proteiniphilum, Fermentimonas and Truepera had more abundance in the soil of cow barns at the non-lactation stage; the saline-alkali tolerant bacteria such as Desulfobacterium, Halomonas and Thioalkalispira had more abundance in the soil of dry cow barns and post-weaned calf barns. Pathogenic bacteria such as Acinetobacter and Sphingobacterium had more abundance in the soil of high-yielding lactating cow barns.

Key words: Holstein cows, different groups, barn soil, bacteria