Breeding low-methane sheep
Working on projects funded by the Pastoral Greenhouse Gas Research Consortium (PGgRc), AgResearch scientists have made the world-leading discovery that a low-methane flock produced consistently lower emissions, even when tested on a variety of feeds.
Scientists John McEwan and Dr Cesar Pinares are now joining forces in a three-year PGgRc/Sustainable Land Management and Climate Change (SLMCC) project to ascertain if the low-methane sheep pass their emissions profile on to their offspring, and to determine that they are also efficient producers. Any breeding programme would need to cut methane without compromising production.
PGgRc Manager Mark Aspin says the expansion of this programme is a logical step that arises from the promising leads found initially through screening 700 dairy cattle, and then confirmed in the last 18 months with the work on sheep. This project is part of a wider programme under the PGgRc that is also investigating phenotypic markers and candidate genes in cattle.
Dr Pinares is testing progeny of sires from the low methane flock to measure the amount of methane emitted per unit of feed eaten, while John McEwan is providing genetic and genomic skills to understand how genetically variable the low-methane trait is, and how it is related to other traits, such as productivity. The PGgRc/SLMCC project is also a collaboration with Ovita, and Meat & Wool New Zealand, who provide research animals.
Repeatedly measuring the animal’s methane emissions in a respiration chamber is laborious, and expensive, so the project also aims to come up with a faster, cheaper way to obtain emission estimates and facilitate breeding programmes. Options include genomic selection using a SNP chip (a cutting-edge technology that enables the scanning of up to 50,000 genetic variants at once) or seeing whether blood or saliva testing can be used to find low-emission animals.
Mr McEwan says results from the first pilot project point towards the low-methane trait being genetically variable - and it’s hoped that exploring the genetics behind these low-methane sheep will eventually result in breeding programmes for low-emission sheep, cows, goats and deer.