Belfast researchers hope feeding seaweed to cows will cut emissions

12 Nov 2021

Image: © jean-luc rollier/EyeEm/

Scientists at Queen’s University Belfast are collaborating with Teagasc and others to conduct trials on cattle using local seaweed varieties.

Scientists at the Institute for Global Food Security (IGFS) at Queen’s University Belfast are conducting research into the possibility of reducing livestock methane emissions using seaweed supplements.

Early lab research at IGFS has shown promising results for emissions reduction by adding native Irish and UK seaweeds into the diet of cows. Previous research from Australia and the US has shown reductions of up to 80pc in methane emissions from cattle after they were given seaweed supplements.

Future Human

However, these studies used a red seaweed variety, which grows mainly in warmer climates. These red seaweeds also contain high levels of bromoform, which is known to be damaging to the ozone layer. Seaweeds indigenous to the UK and Ireland tend to be brown or green and do not contain bromoform.

UK and Irish seaweeds are also rich in active compounds called phlorotannins, found in red wine and berries. Phlorotannins are anti-bacterial and could potentially improve animals’ immune systems.

The IGFS is to conduct trials on UK farms using brown and green seaweed varieties. The institute has inked a three-year partnership with UK supermarket chain Morrisons, which will provide access to its network of beef farmers.

The project also includes the Agri-food and Biosciences Institute (AFBI) in Northern Ireland as a partner. IGFS and AFBI are also joining a €2m international project led by Irish agricultural research agency Teagasc. Researchers involved in this project will monitor the effects of seaweed in the diet of pasture-based livestock. They will add seaweed to grass-based silage on dairy cow farms in Northern Ireland starting next year.

As well as assessing the methane emissions of beef and dairy cows from burping and flatulence, these projects will assess the nutritional value of indigenous seaweeds and how they affect meat quality.

“The science is there,” said IGFS lead Sharon Huws, professor of animal science and microbiology in the School of Biological Sciences at Queen’s.

“It’s simply a matter of providing the necessary data and then implementing it. Using seaweed is a natural, sustainable way of reducing emissions and has great potential to be scaled up. There is no reason why we can’t be farming seaweed – this would also protect the biodiversity of our shorelines.

“If UK farmers are to meet a zero-carbon model, we really need to start putting this kind of research into practice. I hope IGFS and AFBI research can soon provide the necessary data and reassurance for governments to take forward,” Huws added.

The researchers’ efforts come as methane emissions continue to be debated at COP26 in Glasgow this week.

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Blathnaid O’Dea is Careers reporter at Silicon Republic