The first large-scale characterisation of methane emissions in Irish beef cattle has shown that some beef cattle can produce up to 30% less emissions, on average, for the same level of productivity.
Novel research led by Teagasc, in collaboration with University College Dublin (UCD) and the Irish Cattle Breeding Federation (ICBF) is making strides towards identifying and, ultimately, breeding for low-methane-emitting beef cattle in a bid to improve the environmental sustainability of the national beef cattle herd in Ireland.
To date, the genetic selection of low-methane-emitting ruminant livestock has been limited by the relationship of methane output and feed intake.
Teagasc PhD student, Paul Smith explained:
“In general on the same plane of nutrition, animals that consume more feed tend to produce more methane on a daily basis.
“This relationship has, so far, made it difficult to breed low-methane-emitting animals without negatively impacting feed intake, which is a key driver of animal productivity, particularly in forage-based production systems.”
However, Teagasc’s Prof. Sinéad Waters, Prof. David Kenny, Paul Smith and Stuart Kirwan, along with UCD’s Dr. Alan Kelly and ICBF’s Dr. Stephen Conroy, working collaboratively through an ERA-GAS-funded project ‘RumenPredict’, have developed a novel approach to quantifying emissions in beef cattle, capable of disentangling the relationship of feed intake with methane output.
In their study, recently published in the American Journal of Animal Science, the group showcase the benefits of utilising a new concept termed residual methane emissions (RME) to select low-methane-emitting animals without impacting animal productivity.
The study is the first large scale measurement of methane emissions in Irish beef cattle and one of the largest conducted worldwide.
What is RME?
RME can be defined as the difference between an animal’s actual and expected methane output, based on the quantity of feed that it consumes on a daily basis and its bodyweight.
Describing the study, Paul added:
“We calculated RME values for 282 beef cattle undergoing feed efficiency and methane measurements at the ICBF Progeny Test Centre in Tully, Co. Kildare.
“After ranking animals as high, medium and low on the basis of RME, low RME animals produced 30% less methane, but maintained the same level of feed intake, feed efficiency, growth and carcass output as their high ranking RME contemporaries.”
Discussing the significance of the findings, Teagasc researcher, Prof. Waters said: “Considering the recent greenhouse gas emissions targets set out in the government’s Climate Action Plan and particularly our requirement to reduce biogenic methane, the ‘RumenPredict’ project demonstrates the future potential to breed beef cattle with lower emissions.”
This project was the first to employ GreenFeed technology to measure emissions in Irish cattle and this technology has now been deployed across Teagasc, UCD and ICBF research facilities, enhancing national capacity to accurately measure methane emissions.
Head of animal and bioscience research at Teagasc, Prof. David Kenny said this new measurement approach, coupled with ongoing work to develop nutrition-based mitigation solutions, will deliver a more resilient Irish beef industry.
Senior author on the study, UCD’s Dr. Alan Kelly said that from a research perspective, it will be important to understand the biology underlying why these cattle produce less methane.
Commenting on the future direction of this research, ICBF’s Dr. Andrew Cromie said:
“The next step for the ICBF, Teagasc and UCD team will be to broaden the investigation into the relationship between RME and other important traits at a genomic level with a view to harnessing this information within our national beef cattle genetic selection indices.”