Seaweed could reduce levels of methane cows belch into the atmosphere

Seaweed could reduce levels of methane cows belch into the atmosphere
Bacteria in the guts of cattle produce methane as they help the animals breakdown grass and grains -- but seaweed may help reduce the methane cattle expel. Photo sspiehs3/Pixabay

March 17 (UPI) -- When a bit of seaweed is added to a cow's diet, they become much less gassy.

According to a new study, published Wednesday in the journal PLOS One, the addition of scant amounts of seaweed to the diet of beef cattle reduced methane emissions by more than 80 percent.


Previous studies have hinted at the promise of seaweed as a dietary additive for grain-fed livestock, but the latest study was one of the first to measure the effects over several weeks.

Red seaweed, Asparagopsis taxiformis, contains a high concentration of compounds that prevent the binding of carbon and hydrogen, thus limiting the generation of methane inside a cow's digestive tract -- and the amount belched into the air.

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For the study, researchers fed 21 cows roughly 3 ounces of red seaweed per day for 21 weeks.

Over the course of the study, researchers periodically measured the methane emissions of seaweed-fed cows and cows subsisting only on grass and grains. Scientists also tracked the weight of the seaweed-eating cattle.

The seaweed had no impact on weight gain, but it did drastically reduce methane emissions.

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"Never would I have expected that we can see reductions of over 80 percent and the animals doing just great," study co-author Ermias Kebreab, a professor of animal science at the University of California, Davis, told UPI in an email.


Researchers were especially encouraged by the fact that methane reduction levels remained stable over several months.

"We show for the first time that seaweed is effective for at least 21 weeks, alleviating the concern that microbes might get adapted to it," Kebreab said.

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The study's data suggests seaweed has a larger impact on the methane emissions from low-forage, grain-fed cows, as opposed to cattle that get most of their calories from grazing on grass in the field.

Kebreab and his research partners used what are called "cow cookies" to measure the methane belched by the study's bovine subjects -- it's kind of like a treat-dispensing breathalyzer.

"We use an equipment called GreenFeed that drops feed so animals come willingly to it, and as they eat the cow cookie, we measure their emissions," he said.

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Though scaling production remains a problem -- one scientists are currently working on -- scientists were able to prove that seaweed's active ingredient is shelf stable for up to three years.

Scientists are currently working on ways to make their seaweed additive more user-friendly and cost-effective for farmers.

"We are going to work on how we can deliver this to cows on pasture and also develop a protocol so that farmers can claim carbon credits," Kebreab said.


Though methane is less abundant than carbon dioxide, it is a more potent greenhouse gas, boasting 30 times more heat-trapping power than CO2. Thus, curbing methane emissions, can help slow climate change.

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