Low-methane cattle help cut climate impact of beef production
Image credit: Dreamstime
The climate change impact of cattle rearing is typically much worse than other livestock agriculture due to the high methane emissions from the animal’s digestive system. But new research has found that some beef cattle can produce up to 30 per cent less methane emissions, on average, for the same level of productivity.
Researchers from Ireland’s agriculture agency Teagasc, alongside University College Dublin (UCD) and the Irish Cattle Breeding Federation, believe they have made strides towards identifying, and ultimately breeding for, low-methane-emitting beef cattle in a bid to improve the environmental sustainability of the meat.
Until now, the genetic selection of low-methane-emitting livestock has been limited by the relationship of methane output and feed intake.
“In general, on the same plane of nutrition, animals that consume more feed tend to produce more methane on a daily basis,” researcher Paul Smith said.
“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.”
But the team has recently developed a novel approach to quantifying emissions in beef cattle which is capable of disentangling the relationship of feed intake with methane output.
A new concept termed 'residual methane emissions (RME)' has been developed to help select low-methane-emitting animals without impacting animal productivity.
Residual methane emissions 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.
Using 282 beef cattle in the trial, they use the RME grading system to rank the animals as either high, medium or low, depending on their output.
Low RME animals produced 30 per cent less methane, but maintained the same level of feed intake, feed efficiency, growth and carcass output as their high-ranking contemporaries.
Teagasc researcher Professor 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 methane emissions.”
This project was the first to employ GreenFeed technology to measure methane emissions in Irish cattle and this technology has now been deployed across various research facilities.
Senior author on the study, UCD’s Dr Alan Kelly added: “These are really encouraging findings for Irish beef producers. Low RME cattle from the national beef herd produced a third less methane for the same level of performance and feed input, with these emission differences recorded for all universally accepted metrics of methane expression, be it daily emissions, methane yield or methane intensity. Going forward, from a research perspective, we need to understand the biology underlying why these cattle are producing less methane.”
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