A link between a bulls’ genetics and the amount of methane they produce is being investigated. If successful farmers will be able to breed cows that burp less methane per kg of feed eaten.

In 2020, a pilot trial, by CRV and LIC with funding from the New Zealand Agricultural Greenhouse Gas Research Centre, measured feed intake and methane emissions – in the form of burps – from 20 young bulls destined to father the next generation of New Zealand’s dairy cows.

That research progressed to a much larger study where operations were scaled up to collect measurements from the full intake from CRV and LIC’s Progeny Test Scheme. The bulls are housed in a purpose-built barn and fed lucerne cubes in feed bins that measure how much each bull eats.

The bulls independently visit a special methane measuring device. While there, they are fed pellets and methane from their burps and breath is measured.

Results from the first year found there was a genetic variation in the amount of methane emitted after accounting for the amount of feed eaten by the bulls, with the lowest bulls emitting around 15-20% less methane than the average.

Around 10% of the variation that we see in methane is due to the genetics of the animal (heritability). The next step in the research is to see if the genetic variation responsible for methane emissions in growing young bulls is replicated in their daughters.

Measurements are currently being taken from those heifer calves.