Study shows supplementing cows' diet with seaweed reduces their methane emissions by 80%

Sea Forest's farm is on track to producing 7,000 tonnes of Asparagopsis. PHOTO: SEA FOREST

SINGAPORE - Industrial-scale beef production is impacting global climate, but scientists have found a way to make cattle-rearing more environmentally-friendly.

Research has shown that feeding cows a type of red algae seaweed can reduce the amount of methane they release from both ends by as much as 80 per cent.

Cows have microbes in their stomachs which help them digest their food via a process known as enteric fermentation.

Methane, which is a by-product of digestion, is then released into the atmosphere when the cow belches or farts. Around 70 per cent of methane emissions from agriculture is due to enteric fermentation.

However, when a small amount of a red algae seaweed, known as Asparagopsis taxiformis, was used to supplement the cows' diet over five months, their methane production dropped by 80 per cent.

Seaweed consumption accomplishes this by preventing hydrogen and carbon atoms from binding.

In the course of the study, 1.5 to 3 ounces of seaweed were added to the feed of 21 beef cattle. They released up to 750 per cent more hydrogen than before - a result of producing less methane. Hydrogen, unlike methane, has minimal impact on the environment.

The research findings were published in the scientific journal Plos One on March 17.

This builds on the team's initial research on dairy cows which found that consuming 10 ounces of seaweed a day over a three-week period could reduce the cows' methane production by up to 67 per cent.

The larger challenge, however, concerns the viability of scaling up commercial seaweed production to feed the world's one billion cattle.

Marine biologist Jennifer Smith from the Scripps Institution of Oceanography at UC San Diego has been researching how best to grow the seaweed productively in Southern California.

Part of her research involves manipulating the concentration of bromoform - a compound found in seaweed which is responsible for interfering with the enzymes that produce methane.

"If we can grow seaweed that is ten times more concentrated in bromoform than what exists in nature, just by manipulating factors such as temperature, light, and carbon dioxide - we could be potentially making a superior product," she told The Straits Times.

She noted that various companies in Australia, Vietnam, and countries in Europe have been racing to innovate and commercialise seaweed farming that is suited for each respective country and their climate.

In Australia, for instance, environmental biotechnology company Sea Forest was awarded a $1 million commercialisation grant from its government to fast track seaweed production for use as cattle and livestock feed.

Its farm in Tasmania is on track to producing 7,000 tonnes of Asparagopsis for the beef and dairy industries by next year.

Research led by the Commonwealth Scientific and Industrial Research Organisation found that the Asparagopsis seaweed is effective in reducing the methane emissions of cow and sheep by up to 98 per cent when added to their diets.

Mr Sam Elsom, chief executive of Sea Forest, said that the grant will fast track the company's ability to scale and supply the supplement to farms across Australia and globally.

He noted that around 20 per cent of the cow's energy is lost when converting its feed into methane, so reducing methane production would mean greater feed efficiency, that is less food needed to grow the livestock.

The company is currently working with farmers to validate productivity gains for larger herd sizes in commercial farms.

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