Research update: Dietary oil to reduce methane
Stuart Kirwan, Neal Folliard and Emily Roskam report on Teagasc Grange research that examined suppressing methane production with dietary oil.
In Ireland, agriculture accounts for ~34% of greenhouse gas (GHG) emissions. Enteric methane, a potent GHG, accounts for 65% of these agricultural emissions. Enteric methane is produced as a result of the fermentation of feed in the rumen, predominantly from cattle and sheep.
Under EU legislation, Ireland has committed to reduce agricultural GHG emissions by 25% by 2030. Therefore, reducing the quantity of methane emitted by livestock will be essential to achieving this target.
Dietary supplements such as 3- NOP and calcium peroxide based compounds have received a lot of attention recently for their efficacy in reducing methane production. However, these products are two to three years from being licensed for beef production within the EU.
Recent studies in Teagasc Grange examined the effectiveness of supplementing beef cattle with linseed oil and rapeseed oil, offered twice daily mixed into concentrate feed, as a methane inhibitor.
Supplementing linseed oil at 4% of dry matter intake (DMI) reduced methane production by 19% without any negative effect on DMI, digestibility or growth rate.
Supplementing rapeseed oil and cold-pressed rapeseed cake at 2.5% and 14.5% of DMI, respectively, with both diets balanced for oil content, had no negative effect on DMI, digestibility or performance, and reduced methane production by 8%.
While these products effectively reduced methane production, their use in beef diets may be cost prohibitive. However, further research is warranted to evaluate any possible synergistic benefits of supplementing oils in tandem with other methane mitigating compounds.