Submitted to: SpringerPlus
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/30/2015
Publication Date: 8/26/2015
Publication URL: http://handle.nal.usda.gov/10113/61315
Citation: Myer, P.R., Wells, J., Smith, T.P., Kuehn, L.A., Freetly, H.C. 2015. Microbial community profiles of the colon from steers differing in feed efficiency. SpringerPlus. 4:454.
Interpretive Summary: Feed is the primary cost associated with beef production. The gastrointestinal tract of cattle contains a diverse microbial community that aids in digestion by fermentation of the feed. The fermentation products of the microbiota dictate the nutrient profile that an animal receives in this process. Beyond the rumen, studies that relate gut microbiome to cattle performance are sparse. The relationship between bacterial community and feed efficiency is poorly understood. To gain a comprehensive understanding between the bacterial community and feed efficiency beyond the rumen, we examined the microbiome of the colon from steers differing in feed efficiency. We found that there are shifts in populations of some bacteria in the colon of beef cattle associated with feed efficiency.
Technical Abstract: Ruminal microbial fermentation plays an essential role in host nutrition, and as a result, the rumen microbiota have been a major focus of research examining bovine feed efficiency. Microbial communities within other sections of the gastrointestinal tract may also be important with regard to feed efficiency, since it is critical to the health and nutrition of the host. The objective of this study was to characterize the microbial communities of the colon among steers differing in feed efficiency. Individual feed intake (FI) and body weight (BW) gain were determined from animals fed the same ration, within two contemporary groups of steers. Four steers from each contemporary group within each Cartesian quadrant were sampled (n=16/group) from the bivariate distribution of average daily BW gain and average daily FI. Bacterial 16S rRNA gene amplicons were sequenced from the colon content using next-generation sequencing technology. Within the colon content, UniFrac principal coordinate analyses did not detect any separation of microbial communities, and bacterial diversity or richness did not differ between efficiency groups. Relative abundances of microbial populations and operational taxonomic units did reveal significant differences between efficiency groups. The phylum Firmicutes accounted for up to 70% of the populations within all samples, and families Ruminococcaceae and Clostridiaceae were highly abundant. Significant population shifts in taxa were detected, including the families Ruminococcaceae, Lachnospiraceae, and Sphingomonadaceae, and the genera Butyrivibrio, Pseudobutyrivibrio, Prevotella, Faecalibacterium and Oscillospira. This study suggests the association of the colon microbial communities as a factor influencing feed efficiency at the 16S level.