30. Breeding for lowered methane emissions using rumen microbial profiles in sheep

Abstract

Reducing methane emission in ruminant animals via breeding requires estimating methane emissions using indirect or proxy measures, as direct measures are often impractical. Rumen microbial community (RMC) profiles have been shown to be associated with methane emissions and so may be a suitable proxy. Using a dataset of 3,640 sheep across 8 genetically linked flocks, we predicted methane emission from RMC profiles and obtained higher prediction accuracies compared to host genomic prediction. We estimated the correlations between methane traits measured directly using portable accumulation chambers (PAC) and predicted from RMC profiles. Moderate to high genetic correlations (0.66 and 0.77) were obtained, while phenotypic correlations were lower (0.32 and 0.35). These results suggest RMC profiles have potential to be used as a proxy for methane emissions in ruminants and that direct and indirect methane measures could be combined within a breeding scheme.