PALMERSTON NORTH, New Zealand — How to stop a cow from burping?
This may sound like the beginning of a humorous puzzle, but it is the subject of a major scientific study in New Zealand. And the answer could seriously affect the health of the planet.
More specifically, the question is how to stop cows, sheep and other farm animals from emitting so much methane, which doesn’t last as long in the atmosphere as carbon dioxide but is at least 25 times more potent. Global Warming.
Because cows cannot easily digest the grass they eat, they first ferment it in several stomach compartments or the rumen, a process that releases large amounts of gas. Every time someone eats a beef burger or drinks a milkshake, it costs the environment.
New Zealand scientists are proposing some surprising solutions that could put a big dent in these emissions. Among the more promising ones are selective breeding, genetically modified feed, methane inhibitors, and a potential game changer—vaccination.
From feeding animals more seaweed to giving them a kombucha-style probiotic called “Kowbucha,” nothing is off the table. A British company has even developed a wearable harness for cows that oxidizes methane by releasing it.
In New Zealand, research has taken on a new urgency. With agriculture central to the economy, about half of the country’s greenhouse gas emissions come from farms, less than 10% of the US, New Zealand’s 5 million people have 26 million sheep and more than 10 million cattle.
The New Zealand government has pledged to reduce methane emissions from farm animals by 47% by 2050.
Last month, the government announced plans to start taxing farmers for burping animals, a world-first move that has angered many farmers. All parties hope they can take a break from science.
Much of the research is conducted at the Palmerston North campus, which some jokingly refer to as Gumboot Valley, a nod to Silicon Valley.
“I don’t believe there is anywhere else in New Zealand that is more ambitious in terms of the technologies being researched,” said Peter Janssen, chief scientist at government-owned AgResearch, which employs about 900 people.
The research is based on studies showing that reducing methane should not harm animals or affect the quality of milk or meat. Janssen said microbes that live in animals and produce methane are opportunistic rather than integral to digestion.
He has been working on developing a vaccine for the past 15 years and has been focusing intensively on it for the past five years. It has the potential to reduce the amount of methane belched by cows by 30% or more, he said.
“I certainly believe it will work because that’s the motivation to do it,” he said.
The vaccine will stimulate the animal’s immune system to produce antibodies, which will reduce the output of methane-producing microbes. A great advantage of vaccination is that it probably only needs to be administered once a year, or even once in an animal’s lifetime.
Inhibitors that work similarly are compounds given to animals that directly dampen methane microbes.
According to Janssen, the inhibitors could reduce methane by at least 30% and possibly 90%. The challenge is that the compounds must be safe for animal consumption and must not pass to humans through meat or milk. Inhibitors should also be administered regularly.
Both inhibitors and vaccines are several years away from being ready for the market, Janssen said.
Other technologies, such as selective breeding, which can reduce methane production by 15%, will be introduced on sheep farms early next year, Janssen said. A similar program for cows may not be far behind.
Scientists have been testing sheep in chambers for years to find differences in how much methane they belch. Low emitters have been bred and low-emission offspring have been produced. Scientists also look for genetic traits that are common to low-absorption animals and can be easily identified.
“I think one of the areas where New Zealand scientists in particular have made great progress is in this whole area of livestock,” said Sinead Leahy, senior science adviser at the New Zealand Agricultural Greenhouse Gas Research Centre. “And in particular, there’s been a lot of research into breeding low-emission sheep.”
Another target is animal feed, which scientists say has the potential to reduce methane production by 20% to 30%.
In one of the greenhouses on campus, scientists are developing genetically modified clover. Visitors should wear boots and medical scrubs and not drop items to avoid any cross-contamination.
Because New Zealand farm animals often eat outside in fields rather than in barns, methane-reducing feed additives such as Bovaer, made by the Dutch company DSM, are not particularly helpful, the scientists explain.
Instead, they are trying to genetically modify the rye and white clover that New Zealand’s animals mainly eat.
With alfalfa, scientists have found a way to increase the tannins that help prevent methane production.
“What this team has done with their research is to identify a key switch that activates condensed tannins in leaves,” said Linda Johnson, science group manager at AgResearch.
Laboratory analysis shows that modified alfalfa reduces methane production by 15% to 19%, Johnson said.
The alfalfa program goes hand in hand with the ryegrass program.
Richard Scott, chief scientist at AgResearch, said they were able to increase the oil level in rye leaves by about 2%, which research shows should lead to a 10% reduction in methane emissions.
But like inhibitors and vaccination, the feed program is still several years away from farm readiness. Scientists have completed controlled trials in the US and plan to conduct larger field trials in Australia.
However, New Zealand has strict regulations banning most genetically modified crops, a regulatory hurdle scientists will have to overcome if they want to introduce the modified feed to the country’s farms.
In another study, dairy company Fonterra is testing the probiotic Kowbucha blend, and British company Zelp is continuing to test and improve its wearable harness. Other tests show that a red seaweed called Asparagopsis reduces methane when eaten by cows.
But farmers don’t expect all research to yield results. Aidan Bichan, a farmer at Kaiwaiwai Dairies near Featherston, said they were reducing methane emissions more efficiently.
These include increasing milk production per cow, using less processed feed and changing milk cows less often, he said.
“At the farm level, we have to do everything we can to save the planet,” Bichan said.