New Zealand scientists ‘potty train’ cows for climate benefits

But it begins in the gut of ruminant livestock, which use microbes to partially digest their food by fermenting it in a compartment of their stomach before regurgitating it to be chewed as cud.

There are estimated to be 1.5 billion cows on the planet, with each one capable of producing 500 litres (132 gallons) of the gas each day.

In addition, livestock urine produces nitrous oxide, another powerful climate pollutant.

‘Tantalisingly close’

New Zealand’s farm-reliant economy means its proportion of agricultural emissions is much higher, accounting for around half of its greenhouse gases.

At Clark’s centre in Palmerston North, the major focus is on livestock methane, which accounts for almost 36 per cent of the country’s total.

“New Zealand has a specific problem and it’s imperative we give farmers the tools and technologies to reduce their emissions,” Clark said.

The facility, which is vetted by an ethics committee, is exploring research that includes selective breeding programmes to develop bloodlines of animals that naturally produce less gas.

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Sheep have been bred that produce 10 per cent less methane than average and Clark said researchers were trying to produce similar results with cattle.

Other projects include putting emission-inhibiting additives in livestock feed and even developing a harness or mask with filters that capture methane before it leaves the animal’s mouth.

But Clark said perhaps the most exciting prospect being developed in Palmerston North is a vaccine that reduces methane by targeting the microbes in the gut that produce the gas.

“It’s tantalisingly close, in the sense that it works in the laboratory but it doesn’t work in the animal yet,” he said, adding such a vaccine could be easily administered to flocks and herds worldwide, with an immediate impact on global emissions.

But critics warn this approach offers only short term benefits and “Band-Aid” solutions to major problems.

“Reducing methane output while breeding still more methane-producing animals ignores animal suffering, deforestation, and the increased risk of diseases – including zoonotic viruses – all associated with animal agriculture,” said Aleesha Naxakis of People for the Ethical Treatment of Animals.

Global shift

New Zealand’s government has committed to reducing livestock methane 10 per cent by 2030 and 24-47 per cent by 2050, compared with 2017 levels.

But some have questioned why the lucrative agricultural sector is treated differently to the rest of the economy, which has been set a target of zero net emissions by 2050.

Monitoring website Climate Action Tracker rates New Zealand’s climate policies as “highly insufficient”, citing the methane carve out as one of the main reasons.

“As we look toward COP26, unless governments take immediate steps to transition our global food system away from animals and towards plants, we’re setting fire to the only home we have,” Naxakis said.

Clark conceded “getting rid of livestock, and eating more plant-based foods” would reduce agricultural emissions and make both people and the planet healthier, but said the situation was more complex.

He said pursuing such a major shift, rather than working to lower livestock emissions, would have significant economic and social consequences on the sector worldwide.

Clark added that the government’s funding of research into livestock emissions was only partly to do with New Zealand’s reliance on the sector.

“Sure there’s an element of self interest, but there’s a bit of altruism there as well,” he said.

“If we can find solutions that are applicable elsewhere, that help tackle emissions in China, the US, or wherever, then New Zealand could make a major contribution, as a small nation, to the global effort to reduce emissions.”