Early indications are showing promising results on using a feed additive to reduce the amount of methane produced by Irish cattle.

In Teagasc’s July newsletter, Sinead Waters and Stuart Kirwin outline that a number of feed additives are being examined to identify if they can reduce cattle’s methane emissions.

Over 56% of greenhouse gas (GHG) emissions from agriculture arises from enteric fermentation, and Teagasc believes an opportunity exists to reduce methane emissions from ruminants through dietary manipulation and feed additives.

Feed additive research

As part of the METH-ABATE project funded by the Department of Agriculture, Food, and the Marine (DAFM), a number of in-vitro studies were conducted at Teagasc Grange using the rumen simulation technique (RUSITEC) system.

The studies aimed to assess the potential of feed additives for their methane mitigation potential.

One of the most promising feed additives tested to date is oxidising methane inhibitors.

These are synthetic peroxide-based compounds, such as urea hydrogen peroxide or potassium iodide.

Early results from the RUSITEC are encouraging, with approximately 60% reductions in methane observed, with no negative effects on digestibility.

Following on from this, a feeding trial is planned to commence in August to see if the results obtained in the RUSITEC experiment can be replicated in the live animal.

Research to date has highlighted that in order for any feed additive to be effective in reducing methane from ruminants, the additive must always be present within the rumen.

This will be challenging to adapt to Ireland’s renowned pasture-based cattle rearing systems.

Pasture-based country

The next phase of the project will develop technologies for pasture-based production systems.

Development of encapsulation technologies and slow release bolus formulations for feed additives, including oxidising methane inhibitors, is currently underway to ensure that the most promising feed additives can be delivered at pasture.

Based on current figures, agriculture contributes 34% of the overall GHG emissions in Ireland and methane accounts for the majority of GHGs arising from agriculture.

Methane is 28 times more potent than carbon dioxide (CO2) and is produced from rumen microbial fermentation and stored manure and slurry on farms.

Teagasc believes that suppressing the quantity of methane emitted by livestock “will be essential” to achieving the agricultural sector’s target of a 10% reduction in enteric methane emissions by 2030.