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Designing a more climate-friendly cow

The world has spent a century pumping up cows to produce more milk and meat. Can we now reinvent them to produce less damaging methane?

By Katharine Gammon

In a pastoral scene apparently unchanged for centuries, Holstein cows calmly graze the electric green fields of Peter Hynes’s farm in County Cork, Ireland. But thanks to intensive breeding and technological advances, Hynes’s 180 dairy cows produce over twice the amount of milk their predecessors did even 50 years ago. The problem is, until recently they burped just as much methane.

Far from existing in harmony with nature, livestock farms are responsible for more greenhouse gasses than all the planet’s factories and construction combined – about 14 percent of global emissions – and rising. That’s because methane has 25 times the warming potential of carbon dioxide, and each of the world’s 1.6 billion cows produces up to 500 liters of the gas every day. 

At least, most of them do. 

Hynes’s heifers are different. His is the first commercial farm in Ireland to feed the cows Bovaer, a supplement that reduces the methane they emit by 30% or more. Hynes’s herd is at the vanguard of a new movement to reinvent the cow for a rapidly warming 21st century, a movement that includes breeding programs, genetic engineering, and even gas masks. 

But are such high-tech innovations a helpful step towards meeting our climate goals, or just a bandaid for our continued consumption of environmentally destructive beef and cheese?

First up, cow biology 101. Strictly speaking, we shouldn’t blame cows for producing all that warming methane. The guilty parties are actually billions of microbes in their rumens—a cow’s largest stomach compartment. These microbes enable cows to digest the tough fibers in grass but generate hydrogen and carbon dioxide along the way, a process known as enteric fermentation. Enzymes in the rumen then combine those gasses to form methane. 

Researchers have long experimented with making cows better global citizens by feeding them everything from turmeric to seaweed. One kind of seaweed called Asparagopsis taxiformis has been shown to reduce methane by up to 95% in cows. Scientists think the seaweed binds to the enzymes that convert hydrogen and CO2 to methane, reducing their activity. However, A. taxiformis only grows in parts of Australia and New Zealand, and harvesting enough to feed billions of cattle would be simply impossible. 

A teaspoon of white powder is dropped into the cows’ feed and starts slowing down methane production within 30 minutes.

Bovaer targets the same enzymes, temporarily suppressing them to slow down methane production. Its key advantage is that it can be synthesized, cheaply and at scale, in factories worldwide. 

“It was not that we just found something on the shelf, which was designed for something else and relabeled for methane production,” says Maik Kindermann, the scientist at the Dutch multinational DSM who invented Bovaer. “It’s uniquely made for emission reduction in the agricultural sector.” 

The additive is a quarter of a teaspoon of white powder that is dropped into the cows’ feed and starts working within 30 minutes. It is already being fed to around 100,000 cows worldwide, mostly in Europe, according to the company. In January, Canada also approved its use.

Hynes heard about the supplement and was impressed with the scientific research behind it.  “Given the work was peer reviewed, also the fact that it was licensed for use on dairy stock in the EU and was being used on farms in mainland Europe, I thought: why aren’t we feeding it here?” he says. His cows are fed Bovaer, which has a monthly cost of around 7 Euros per head, when they return to their barn from pasture. 

Because the compound stays in the cow’s stomachs, it doesn’t impact the animal’s milk, meat  or poop, says Frank Mitloehner, an air quality specialist in the Department of Animal Science at UC Davis. That’s beneficial because some dairies want to produce yet more methane from the manure, to burn as a renewable fuel.

Bovaer is expected to hit the US market in the second quarter of 2024—leading to excitement in states like California, which is seeking to reduce dairy methane emissions 40% by 2030. “Many of the agencies in the US are anxious that the compound will make it to market because it is one of the most effective reducers of methane,” says Mitloehner. 

But Bovaer isn’t a climate silver bullet, says Christopher Gambino, a sustainable livestock analyst on the Food and Agriculture team with the Breakthrough Institute, an environmental research center based in Berkeley, California. Yes, it’s been proven effective and safe, but it has limitations. “It’s a tool,” he says, “and we need to find all the tools.” 

First off, Bovaer wears off after just a few hours. When cows aren’t being fed the supplement, their methane burps return with a vengeance—something known as termination shock. Are farmers really ready to commit to using it in perpetuity?

Additionally, not all cows are regularly fed in managed systems like feedlots and barns. Gambino points out that beef cows typically spend six to eight months eating grass on pasture, where 77% of their methane emissions occur. DSM says it is working on a slow release formulation that would work for these animals. 

And while China, Brazil, and the US make up about 30% of cows on the planet, the methane problem is global. Farmers in the developing world might find the supplement too expensive. Even in the US, Mitloehner points out, organic farms probably won’t be able to use Bovaer because it is not a natural ingredient.

Bovaer isn’t a climate silver bullet. When cows aren’t being fed the supplement, their methane burps return with a vengeance, something known as termination shock.

Other solutions are needed, Gambino says, such as changing breeding programs to focus on cows that produce less methane, rather than more milk or meat. Dutch scientists estimate that selectively breeding herds for the climate rather than for financial return could reduce their methane by a quarter by 2050. (Good luck with that, absent tough legislation).

Other researchers think a smarter path is to re-engineer the polluting microbes themselves. The TED Audacious project recently funded UC Davis on a $70 million initiative to genetically modify microbes to naturally produce less methane. Adding baby kangaroo feces to a cow’s diet may have a similar effect, according to a recent paper. Even wearable cow masks that capture burps are on the horizon. But as a tool, Bovaer is cheap and available today. If it is approved in the US next year as expected, it will be quickly adopted in dairies, predicts Gambino. 

Even as vegan lifestyles become more popular in the West, rapidly developing countries are finding an appetite for animal foodstuffs they previously couldn’t afford. Global meat consumption doubled in the 30 years from 1988 to 2018, and is still growing.

“From a realistic perspective, meat is going to keep happening and we will probably have more animals in 2030 [and more again by] 2050, which means we still have to address enteric methane,” Gambino says. “We need all of the above strategies.” 

For Hynes, he’s chasing emission reductions in every possible way on his grassy green farm and feeding Bovaer to his herd is part of that. At the end of the day, he says, the world and the human race needs to eat and clothe itself. “Let’s get on with using science and research to do it in a more climate friendly manner.” 


Katharine Gammon is a freelance science writer based in Santa Monica, California. She writes for a wide range of magazines covering technology, society, and animal science.
Top image: ©Anthropocene Magazine 

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