With an aim of reducing greenhouse gas emissions by three percent per year, the Welsh government is looking for reductions across industries, including agriculture. Now a newly released model shows that with slight changes to trait selection in sheep, farmers can lower methane gas production in their herds by 0.08 percent per year.
Sheep produce methane as a byproduct of the rumen digestion—"the majority of which is actually burped from the nostrils of the animal with a small amount derived from flatulence," Catherine Nakielny of KN Consulting, who helped develop the model, told The Scientist in an email.
Though 0.08 percent is a modest reduction, methane gas has a higher impact on global warming than carbon dioxide. Nakielny's model showed that by breeding for traits that increase litter size, a farmer can increase the efficiency of each breeding ewe, reducing overall energy expenditure in an entire herd. In addition, "increasing longevity [of breeder sheep] would also reduce the number of animals needed to be bought into a breeding system as replacements," said Nakielny.