Research is measuring methane emissions from the burps of young bulls. Photo / Supplied
Research is measuring methane emissions from the burps of young bulls. Photo / Supplied
New research has confirmed bulls' genetics play a role in how much methane they emit, highlighting the potential for farmers to breed low methane-emitting cows in the future.
The news follows the first year of a research programme run by New Zealand artificial breeding companies LIC and CRV and funded by the New Zealand Agricultural Greenhouse Gas Research Centre (NZAGRC).
The research measures methane emissions from the burps of young bulls set to father the next generation of New Zealand's dairy cows.
Together, LIC and CRV, sire 90 per cent of the New Zealand dairy herd through their artificial breeding bulls.
Results from year one, where the feed intake and methane emissions from 281 bulls were measured, found there is genetic variation in the amount of methane emitted, after accounting for the feed eaten by the bulls, with the lowest bulls emitting around 15-20 per cent less methane than the average.
LIC Chief Scientist Richard Spelman said these results were "a big step forward" for the research.
"The amount of methane a bull or cow produces directly relates to the amount of food it eats - generally speaking the more an animal eats - the more methane it will emit.
"But after accounting for differences in the bulls' feed intake, we're still seeing genetic variation in their methane emissions, proving genetics do play a role."
Researchers had a sliding scale from bulls that were low-methane emitters (less than 18g of methane/kg of dry matter eaten) to bulls that were on the higher end (more than 28g of methane/kg of dry matter eaten), Spelman said.
"This is the variation we were wanting to see and we're excited to use it to our advantage."
Although the research was in the early stages, Spelman said the results showed promise to help farmers meet environmental challenges and reduce on-farm emissions.
"New Zealand farmers are striving to meet the challenge of being profitable and sustainable, and research like this will help ensure reducing a farm's emissions doesn't have to come at the cost of reducing its milk production."
CRV Grass-Fed Genetics Manager Peter van Elzakker said the first-year results of the trial aligned with the company's methane work with Wageningen University in the Netherlands.
"The findings in New Zealand are a significant step forward in our work to develop tools to help New Zealand dairy farmers reduce their emissions. They give all of us even more confidence genetics can be part of the solution."
Harry Clark, Director of the NZAGRC, was also pleased with the early results.
"Low-methane selection is now available to sheep breeders and the signs are positive that we might be able to deliver the same for the dairy sector."
The next step in the research was to see if the genetic variation responsible for methane emissions in growing young bulls was replicated in their daughters, Spelman said.
"This year, in partnership with Pāmu, we will breed from bulls that we've identified to be high or low methane emitters.
"After their daughters are born, we'll measure their emissions as growing yearlings and during their first milking season to ensure they're representative of their fathers.
"This is where the rubber will really hit the road in our aim to offer farmers a low-methane breeding solution."
The second year of the research is now underway with methane emissions being measured from approximately 300 young bulls from LIC and CRV's 2022 Sire Proving Scheme.
A research programme run by artificial breeding companies LIC and CRV is one step closer to giving farmers the ability to breed low methane-emitting cows. Photo / Supplied
More about the research programme
How the programme is run • The bulls involved in the trial are housed in a barn so their feed intake can be measured • Bulls help themselves to feed throughout the day. They eat lucerne hay cubes via feed bins which measure how much each bull eats • The bulls independently visit the Greenfeed machine (a special methane measuring device) • They're enticed to visit the machine as they get a small feed of pellets which keeps them in the machine for three to five minutes – enough time to get a methane measurement (ruminant animals burp every 1-2 mins) • Bulls are under 24/7 video surveillance so scientists can monitor them remotely. It also allows scientists the ability to go back and review footage if they see any odd pieces of data from the machines that need further explanation.
The research programme, run by artificial breeding companies LIC and CRV, measures bulls' feed intake and methane emissions - in the form of burps. Photo / Supplied
Timeline 2020: Pilot trial measuring methane from 20 young bulls completed 2021: Methane measured from approx. 300 young bulls (LIC and CRV's 2021 Sire Proving Scheme bulls) completed 2022: Methane measured from approx. 300 young bulls (LIC and CRV's 2022 Sire Proving Scheme bulls) underway. Group of cows mated with high and low methane bulls from 2021: Sire Proving Schemes 2023: Methane measured from approx. 300 young bulls (LIC and CRV's 2023 Sire Proving Scheme bulls). The first offspring from high and low methane bulls born 2024: Methane measurements are taken from yearling daughters 2025: Daughters from high and low methane bulls lactating – methane measurements taken from daughters to ensure they're representative of the methane measurements captured in trial and validate heritability e.g. low methane-emitting bulls produce low methane-emitting offspring, high methane-emitting bulls produce high methane-emitting offspring
If this is successful, then:
2026: Final step - all artificial breeding bulls from LIC and CRV can have a methane breeding value, allowing farmers to select bulls that will produce low methane-emitting cows.
