Genetic Improvement of Beef Cattle for GHG Outcomes

Summary

​Methane yield (MY) has been adopted internationally to compare natural variation between animals in the amount of methane they produce relative to their feed intake.
This project measured MY on young Angus bulls and heifers in two pedigreed, performance-recording research herds. Animals were recorded for MY over a minimum of two days on a controlled intake of a high roughage-content diet. Results for 339 animals were obtained. The results show substantial natural variation in methane emissions between individual animals and significant differences between sires in methane production by their progeny. Compared to the sires whose progeny had the lowest average MY, there were sires whose progeny had an average MY that were 24%, 24%, 16%, 19% and 11% higher across the five groups of cattle tested. A preliminary estimate for the heritability of MY was moderate, being approximately 0.3, and similar to animal weight at the age of test. Methane yield was not strongly associated with phenotypic or genetic variation in standard animal weight, body composition or fertility traits used the Australian beef cattle genetic improvement system BREEDPLAN®. These results show that a breeding solution to reduce methane emissions from beef cattle appears to be possible.​