Environment

Seaweed supplements cut cattle methane emissions by up to 82%

Seaweed supplements cut cattle...
Professor Ermias Kebreab with dairy cows
Professor Ermias Kebreab with dairy cows
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Professor Ermias Kebreab with dairy cows
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Professor Ermias Kebreab with dairy cows
A seaweed species called asparagopsis taxiformis was mixed into cow's regular feed, to try to reduce their methane emissions
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A seaweed species called asparagopsis taxiformis was mixed into cow's regular feed, to try to reduce their methane emissions
Cows at the beef farm during the new experiments
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Cows at the beef farm during the new experiments
A cow eats from a machine designed to measure the methane in its breath
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A cow eats from a machine designed to measure the methane in its breath
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Cattle are a major source of greenhouse gas emissions, mainly due to their methane-loaded burps. A detailed new study has found more evidence that feeding cows a small seaweed supplement can greatly reduce their methane emissions, without affecting their health or the taste of the meat.

Methane might not be as abundant a greenhouse gas as carbon dioxide, but it makes up for that in potency – over a 20-year period it traps 84 times more heat than CO2. Agriculture is the biggest contributor of the gas, with livestock belching out 37 percent of all human-induced methane.

As such, calls are increasingly being made for people to reduce the amount of red meat they eat. And while that’s still a good idea in general, changing our diets might not be the only solution – changing theirs helps too.

Over the past few years, researchers at CSIRO and the University of California Davis (UCD) have shown that slipping just a little bit of seaweed into cattle’s regular feedstock can drastically reduce their methane emissions.

A seaweed species called asparagopsis taxiformis was mixed into cow's regular feed, to try to reduce their methane emissions
A seaweed species called asparagopsis taxiformis was mixed into cow's regular feed, to try to reduce their methane emissions

For the new study, the team scaled up the experiments from two weeks to five months. Over that time they gave 21 beef cattle different amounts of Asparagopsis taxiformis, a seaweed species that grows in tropical Australian waters. This plant seems to work by disrupting enzymes in the animals’ gut that produce methane.

Four times a day, the researchers measured the methane levels in the cows’ breath by having them eat out of a specialized device. The study found that the cows that ate seaweed doses of around 80 g (3 oz) burped out 82 percent less methane than control cows, while still gaining the same amount of weight.

A cow eats from a machine designed to measure the methane in its breath
A cow eats from a machine designed to measure the methane in its breath

Importantly, the efficacy of the methane reduction didn’t diminish over the five-month experiment period. And taste tests showed that there was no change in meat or milk that came from animals being fed the new diet.

“We now have sound evidence that seaweed in cattle diet is effective at reducing greenhouse gases and that the efficacy does not diminish over time,” says Ermias Kebreab, an author of the study.

There are still some logistical hurdles to overcome, however. The team says that it’s difficult to farm this particular seaweed at larger scales, and exactly how the supplements can be administered to free-grazing cows is unclear. But the researchers say these questions will be the focus of future work.

The research was published in the journal PLOS One.

Source: UCD

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6 comments
FB36
This is great improvement for sure but what is really needed is private/government labs doing R&D for a permanent solution (which would also cost a lot less)!:

IMHO, what is really needed is modifying/augmenting gut microbiome of cows so that methane gas never produced or converted to any other harmless chemical!

(Realize such solution could also be helpful/useful for pretty much all humans!)
itsmeagain
If my wife reads this article, she'll start mixing some of that seaweed into my food.
Rustgecko
UC Davis! Well done! Taking credit for work done by an Australian university 2 years ago.

https://www.bbc.co.uk/newsround/49368462
Michael Irving
@Rustgecko UC Davis isn't taking credit for the work - both this study and the previous one were conducted by the same team from UCD and CSIRO.
Techrex
Well, there is another possible way to eliminate the Methane from cattle, BURN IT UP! Create a 'smart' robot drone that flies or runs near the grazing cows, and when they emit a cloud of Methane, the little robot knows it by a tiny sensor on the cow, that is telemetrically linked o the robot, and it waves a small thermal beam back and forth, a few yards above the cow, to ignite the rising methane cloud, make a blue flame 'Fire Ghost'! This produces CO2, which is a greenhouse gas, but Methane retains 27 times more atmospheric heat than CO2, so it could make a dent in global warming anyway!
Robert Lehmert
This is nice, but it is VERY expensive, and would require careful sourcing of the seaweed, which is increasingly subject to die-offs.

Biochar has been used with farm animals for centuries to improve health, and extensive science is available to support that. A 2% addition to the feed ratio or bedding of cattle will reduce enteric methane by 20%. In addition, when the biochar passes through the cow, its vast internal surface will be sorbed in manure, which contains ammonia and other nitrogen compounds. The result is no odor, a less-mobile form of manure that won't migrate into waterways, rich in slow release nitrogen, and a 90% carbon content.

For a peer review report on the science, see: https://tinyurl.com/rx477zcs (optional free download of full report)