Researchers in New Zealand are currently working on a vaccine for ruminant animals, which would help to reduce the amount of methane that they produce.

The Pastoral Greenhouse Gas Research Consortium (PGgRC) has been developing a vaccine in the lab and now needs proof of concept with animals to determine the effectiveness of the strategy.

Senior animal health scientist at AgResearch Dr Neil Wedlock stated: "We still have to get proof of concept that the vaccine will work in animals.

Encouraging results

"We have very encouraging results that indicate a vaccine can work.

"We can get a 20% reduction in methane and that’s quite a big reduction, because some of the other mitigation strategies, although they’re probably further on in terms of proof of concept for the vaccine, they have a more modest reduction in methane."

A number of other research projects are under way at the centre, including research into low-methane genetics, low greenhouse gas feeds and methane inhibitors.

Regulatory hurdles

The methane inhibitors used as feed supplements will most likely be long-term capsules and, according to PGgRC, are five years away from the market if the regulatory hurdles are crossed.

The research into forage crops is proving positive. Animals on trial on brassica crops are showing 25% to 30% less methane than those on dry grass.

Methane emissions

Methane is estimated to account for 68% of greenhouse gas emissions from agriculture in Ireland.

Fifty-eight percent of agricultural emissions come from methane from cattle and sheep, while 10% of the total emissions come from methane emitted from the storage of manure and slurry.

Although early findings from research by Teagasc suggest that the amount of methane produced by dairy cows grazing pasture is overestimated by approximately 30%.

At present, there is huge pressure on to reduce methane emissions from agriculture.

The Climate Action and Low Carbon Development (Amendment) Bill 2021, which is now passed into law, will see carbon budgets for different sectors, including agriculture, set out in the coming months, outlining reduction targets.

Methane reduction will play a key role in meeting these targets.