Phylogenetic identification of rumen microbial organisms linked with significant differences in methane emissions

Summary

​Feed efficiency in cattle has been linked to degree of enteric methane production. Cows which are more efficient in utilizing feed produce less methane, although this response is diet related. The micro-organisms present within the rumen are responsible for the digestion of feed and production of methane. These micro-organisms have been shown to be influenced by both the animal's genotype and diet, with the latter having a greater effect. The aim of this study was to characterise the rumen bacterial, archaeal and fungal communities by deep sequencing technology and to identify micro-organisms linked with high feed efficiency cows producing less enteric methane. We found that cows producing less enteric methane contained a more diverse bacterial community at the level of phyla. The rumen methanogenic archaeal communities from high feed efficient cows were more abundant in methanogenic archaeon related species and less abundant in Methanosphaera stadtmanae. Rumen fungal communities also differed significantly between high and low feed efficient cows. Although, many organisms identified have not yet been grown in the laboratory, the genome sequences generated will enable the development of diagnostic tools to investigate relationships of rumen micro-organisms with methane production, which will be of use in evaluating methane mitigation methodologies.​