March 24, 2016 – For the first time ever, researchers in Australia have discovered that methane emissions from beef cattle are a heritable trait. The milestone research, published online in the Journal of Animal Science, offers the potential for using genetic selection to reduce greenhouse gas emissions from cattle, without altering cattle performance.
Ruminants contribute 80% of global livestock greenhouse gas emissions, and this is mainly through the production of methane. Methane is a by-product of microbial fermentation in the rumen. Methane emissions vary between cattle. An animal’s genetics may be partly responsible for this variation. Now, given this new research, genetics also could be part of the solution.
“Genetic variation in methane emissions is present in beef cattle populations,” said corresponding author Dr. Paul Arthur, a beef geneticist at the New South Wales Department of Primary Industries in Australia. “There is potential to use genetic selection to reduce methane emissions.”
During the study, the researchers found that the heritability of such traits as methane production and yield was “moderate” — which means methane traits stand a good chance of being inherited by offspring. The researchers also found that certain methane traits were weakly correlated with growth and body composition traits, so that selection for lower methane production in cattle would not have detrimental effects on animal productivity.
The study also addressed the high cost and impracticality of measuring methane traits in individual animals, further validating the potential of using genetic selection to reduce methane emissions.
The results suggest that the use of DNA-generated estimated progeny difference (EPD) for methane traits in a selection program could reduce methane emissions in beef cattle by an approximate 5% over 10 years.
Dr. Arthur said the study’s findings are a step closer to paving the way for the development of tools that will allow cattle producers to identify superior bulls whose offspring will have lower methane emissions. All of this could be possible without impacting cattle productivity or producer profitability.
The research has been published in two separate Journal of Animal Science articles: “Genomic heritabilities and genomic estimated breeding values for methane traits in Angus cattle,” and “Genetic and phenotypic variance and covariance components for methane emission and postweaning traits in Angus cattle.”