A trial is underway in the Waikato to see if there is a link between cows' genetics and how much methane they produce.
If such a link is found, it could mean it's possible for farmers to fight climate change by specifically breeding cows that emit less methane.
The trial, involving dairy breeding bulls, is being run by Livestock Improvement Corporation (LIC) and CRV Ambreed, which between them sire 90 percent of the country's dairy herd through their artificial breeding bulls.
Previous studies have shown a link between genetics and methane emissions exists in other animals, such as sheep, giving scientists hope it is present in cows too.
"If we’re successful and establish that the variability of methane emissions between New Zealand dairy bulls can be linked back to their genetics, the opportunity is to utilise this variability to breed cows from lower methane-emitting bulls," Richard Spelman, chief scientist at LIC, said on Tuesday.
"This type of science doesn’t happen overnight but we have real potential to help farmers meet the 2050 methane target under the Climate Change Response Act."
The first stage of the trial will see scientists measure the amount of methane produced by a small number of bulls.
That will be followed by a full trial set to get underway in February 2021, which will aim to identify individual bulls that produce less methane and potentially breed a lower methane-emitting cow.
In the first phase, the methane emitted by 12 young bulls will be measured by LIC, while that of another seven will be measured by scientists at CRV. The results will then be shared, and independently analysed by scientists at the Al Rae Centre at Massey University.
"By 2023 we also hope to validate the methane measurements we captured in young bulls during the initial trial stages were representative of the methane output in lactating cows," said Phil Beatson, R&D manager at CRV.
"This work has the potential to deliver real benefits to farmers in the future by providing another tool to reduce their farm emissions and consequently improve agriculture’s environmental footprint by enabling farmers to utilise these results in their breeding decisions.
"This project is important for several reasons. Firstly, because New Zealand must reduce its methane emissions per unit of feed eaten by cattle, and second because there is real potential for a genetic tool to be developed from this project."
Last year, a programme to breed sheep that produce less methane was undertaken, though it's believed this trial with cows is the first of its kind worldwide.