Methane models over-estimate what Irish cows produce

Methane models currently being used to calculate emissions from Irish agriculture are over-estimating the amount of methane being produced by cattle, Teagasc research is showing.

Dr Laurence Shalloo, Teagasc’s head of animal and grassland research and innovation, has said there is a clear difference between the calculated emissions from cattle and the actual emissions.

Teagasc trials have shown that the carbon footprint of a dairy cow has gone from 1.08kg CO2 equivalent per kg of adjusted milk in calculated emissions to 0.87kg CO2 equivalent in real terms, farmers at the IFA’s recent climate and farming summit heard.

“What we’re measuring [in trials] is substantially below what we’re modelling,” Dr Shalloo told the Irish Farmers Journal, explaining that the models are built on international default values and energy calculations.

However, as Teagasc gets better Irish data, peer reviewed, this will give more accurate emissions factors for Irish animals and ultimately feed into the Environmental Protection Agency (EPA) calculations for Ireland’s greenhouse gas emissions inventory.

Enteric methane

Teagasc research is showing that while high-EBI cows produce about 8% to 10% more milk solids, there is no corresponding increase in enteric methane produced.

“The mathematical models assume that when intake goes up, enteric methane goes up but that is not what we’re seeing,” explained Dr Shalloo.

“We’re seeing that the enteric methane is the same [between high-EBI and low-EBI cows], even though milk yield is higher [for the high-EBI cow].

“We have one year’s data complete?, we have a second year’s data just finished last year, and it’s shown a similar trend. So we’re quite positive that that’s something that potentially, in time, we can get into the national inventory,” he said.

The research paves the way for a breeding pathway farmers can use to reduce emissions per animal, while at the same time making all-round economic sense for the farm too.

Methane-reducing feed additives: how soon can Irish farmers use them?

Using feed additives to cut methane output is one of the promised “technologies” that is included in Ireland’s Climate Action Plan – and is potentially the single biggest factor that will decide whether the blunt instrument of a herd cut is needed to reach the 2023 target.

While effective feed additives such as DSM’s Bovaer are already on the market in some countries, Ireland’s grass-based dairy and beef production systems are at a disadvantage because the feed additive suits feedlot production systems better.

Finding a feed additive that can be effective for grazing cattle is the target.

Irish research on feed additives has shown a 46% drop in methane output from the animal, but only for a few hours following feeding, so the challenge is to develop a slow-release way to cut methane.

Dr Laurence Shalloo, Teagasc’s head of animal and grassland research and innovation, says the challenge is “in a dairy cow setting, you only have two times in the day to get to feed into the animals in the parlour. So how can we get an additive that, while we only feed twice a day, will give us an effect throughout the day?”

Teagasc is working to see how the feed’s active ingredients can be protected in the cow’s rumen or how to slow down their release throughout the day.

“Essentially what we’re trying to do is get a better and a bigger effect from these products,” he explained.

So far, a methane reduction of 7% to 8% has been proven in an Irish grazing-based system, compared to the Bovaer’s 30% (dairy cow) to 45% (beef cattle) reduction in international?feedlot-based research.

Recent Canadian research, published earlier in January, showed a 22% methane cut is possible on a diet of more than 90% forage.

Meanwhile, the New Zealand government has thrown €4.6m behind a programme seeking to create a bolus that will reduce cattle methane emissions by “at least” 70%.

Ruminant BioTech, the company behind the bolus, also received €5.7m in industry backing to finance its plans to bring the emissions bolus to dairy, beef and sheep farmers by 2025.

So how far away are we from Irish farmers being able to feed their cows to reduce methane emissions?

“Realistically, we’re talking a number of years before these things will be available at farm level, from a grazing point of view,” says Dr Shalloo, who adds that he is “very, very positive” that feed additives will play a role “as one of the measures” in Ireland reaching its 25% reduction target by 2030.

Feed additives and other new technologies will come at a cost and there is a debate to be had on who should carry the cost and how farmers can be incentivised to use them, Dr Laurence Shalloo says.

The European Commission has estimated costs for the additive 3-Nitrooxypropanol (3 NOP) from €62 to €110 per animal per year, depending on the dosage included in each day’s ration.

Dr Shalloo maintains that farmers alone can’t carry the cost.

“This has to be spread across, you know, so will there be Government incentives? Will there be milk pricing incentives? Will the consumer end up paying more for a product with a lower footprint?” he asked.

“All that has to be part of the debate,” he said, adding that the development of “carbon farming” could see farmers being paid “not alone for their milk but also for the emissions that they avoided, in terms of the production of that milk”.