Divergent Selection for Methane Yield in Beef Cattle

Genetic selection and breeding to reduce methane production is one option to reduce greenhouse gas emissions, but correlated responses in production traits also need to be considered. The objective of this study was to quantify the effect of divergent selection for methane yield (MY), on methane and body weight traits in Angus cattle. High and Low MY selection lines were created in each of two performance-recorded Angus research herds during the 2011 mating season. This study is a preliminary report on the divergence of these selection lines, as assessed by the performance of the 2013 born progeny. There was no significant selection line by herd interaction. Approximately half a generation of selection was achieved. There was a significant (P<0.05) divergence between the two lines in the selected trait, methane yield. This was also reflected in the significant (P<0.05) selection line differences in the residual methane (actual minus expected methane production) traits and also in the estimated breeding values for these traits. There were no significant selection line differences in birth, weaning and yearling weights.