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A Pellet That Stops Cows From Burping Climate-Warming Methane

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(Bloomberg Businessweek) —

To prevent cows from belching methane, the meat industry is experimenting with adding seaweed to their feed. But harvesters of Asparagopsis, the edible red algae that prevents the greenhouse gas from forming in bovine bellies, may struggle to meet climbing demand. One Australian startup, Rumin8 Ltd., is offering a synthetic alternative that mimics seaweed’s effects.

Methane is the second-largest cause of global warming, and livestock contribute an estimated 32% of emissions generated from human behavior. Just counting the 1.5 billion cows raised for meat globally, that’s 231 billion pounds of methane each year. Giving cows seaweed in their feed could cut 98% of their methane emissions, according to one study.

The relatively recent discovery of the methane-busting powers of Asparagopsis has given rise to a new sector of marine farmers and producers of feed additives. Seaweed takes about four months to be ready for harvest and requires vast tracts of open water to grow; intensive farming could have negative effects on other aquatic life. And it doesn’t come cheap: A report from Australia’s Commonwealth Bank in September estimated that producing a year’s supply of seaweed for the country’s beef industry alone could cost A$132 million to A$1.62 billion ($89 million to $1.1 billion).

Rumin8, based in Perth, is bringing to market products that contain bromoform, the active ingredient in seaweed that inhibits methane production, and they’re made in the lab, not the ocean. Its offerings will include a water-soluble option for free-range cattle and, for less adventurous animals, mineral supplement powders and an oil-based liquid that can be mixed into feed pellets. A slow-release formula in the form of a large tablet is in the works, too.

Laboratory trials conducted by Rumin8 have shown that the additive can reduce emissions from cows by more than 95%, says David Messina, co-founder and chief executive officer. The final product will cost no more than 10% of an animal’s value over its lifetime, he says. Large-scale animal trials are scheduled through this year and next. Rumin8, which is backed by San Francisco-based venture capital firm Prelude Ventures LLC and Australian pension giant Aware Super Pty, expects to start manufacturing in Western Australia in 2023.

Some scientists urge caution, however, regarding the use of seaweed and synthetic alternatives because of their high levels of bromoform, which is banned under the Montreal Protocol, the landmark 1987 environmental treaty that identified chemicals that deplete the ozone layer. “When the world realizes that we might be producing ozone-depleting chemicals to solve methane, well, I don’t know if anyone is going be happy about that,” says Richard Eckard, professor of sustainable agriculture at the University of Melbourne. “A lot of this should still be in the research phase and not in the commercialization phase.”

While there isn’t yet extensive research about what happens to bromoform once it’s ingested by livestock, industry suppliers say the concerns about bromoform are unwarranted. A spokesperson for FutureFeed, a Brisbane, Australia-based producer of a commercial Asparagopsis additive, says there isn’t enough seaweed in the company’s livestock feed to damage the ozone layer, and Rumin8’s Messina says bromoform almost completely breaks down in an animal’s stomach after about three hours, after which point he says it has no impact on the environment.

These assertions are supported by a May 2022 review of literature published in Algal Research, an international academic journal. The nine authors led by Christopher Glasson of New Zealand’s University of Waikato—including three who are involved in commercializing the use of Asparagopsis for methane mitigation—wrote that microorganisms involved in cows’ digestion decompose the bromoform from algae added to their feed. In concluding, they wrote that “large-scale aquaculture of Asparagopsis, and its application in methane mitigation strategies for ruminants at or near minimum effective inclusion levels, may not negatively impact animal health, food quality and ozone depletion.”

Algae-based feed additives and their alternatives have yet to make a dent in methane emissions from livestock. The commercial supply chain is in its infancy, and there aren’t yet incentives for farmers to buy the supplements or regulatory processes to oversee their use. Trials are continuing, including some using varieties of seaweed that contain lower levels of bromoform than Asparagopsis.

Options that aren’t seaweed-based are being studied, too, such as burp masks and a biochar feed additive. Eckard favors a nitrate and bio-alcohol feed additive made by Dutch nutrition company Royal DSM NV, but it would require more frequent feeding of animals for maximum impact, which makes it impractical for free-range cattle. Also, scientists in New Zealand are in the early stages of developing an anti-burp vaccine. Including more fat in cattle diets can reduce methane output by as much as 24%, says Alex Chaves, professor of animal nutrition at the University of Sydney’s School of Life and Environmental Sciences. That’s safer than working with bromoform, he says, calling the substance toxic and unsustainable.

Various approaches may be needed to curb emissions from livestock with the amount of methane in the atmosphere increasing at record rates, including the largest spike last year since monitoring started four decades ago. “For the last 30 years, we’ve spent millions, maybe billions, of dollars trying to mitigate this. We’ve learned lots, but our success has been quite small,” says Chaves. “We have to stop this idea of the ‘silver bullet.’”

Read next: This Startup May Have the Key to Unlock Millions of Tons of Copper

To contact the author of this story:
Sybilla Gross in Melbourne at

© 2023 Bloomberg L.P.


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