TWO NEW projects exploring the impact of seaweed supplements on methane emissions from cattle have been given the green-light to go ahead in the UK.

Through a series of trials involving beef and dairy cattle, researchers plan to assess the supplements' ability to reduce methane emissions, as well as the nutritional value of a variety of homegrown seaweeds, and their effects on animal productivity and meat quality.

During COP6, more than 80 countries signed up to a global methane pledge to cut emissions of the gas by 30% by 2030, bringing discussions on ruminant diets into sharp focus.

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Seaweed has long been hailed a ‘superfood’ for humans but adding it to animal feed to reduce methane gas released into the atmosphere by ruminants' burping and flatulence is a relatively new idea.

Early laboratory research at the Institute for Global Food Security (IGFS) at Queen’s University Belfast has shown promising results using native Irish and UK seaweeds.

Previous research in Australia and the USA found that cattle given supplements from a red seaweed variety resulted in methane reductions of up to 80%. However, these red seaweeds grow abundantly in warmer climates and contain high levels of bromoform – known to be damaging to the ozone layer. Seaweed indigenous to the UK and Ireland tends to be brown or green and does not contain bromoform.

UK and Irish seaweeds are also rich in active compounds called phlorotannins, found in red wine and berries, which are anti-bacterial and improve immunity so could have additional health benefits for animals.

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Now the IGFS science is moving into the field, with trials on UK farms about to begin, using seaweed sourced from the Irish and North Seas as a feed supplement for cattle.

One three-year project is in partnership with the UK supermarket Morrisons and its network of British beef farmers – who will facilitate farm trials. The project also includes the Agrifood and Biosciences Institute (AFBI), in Northern Ireland, as a partner.

A second project will see IGFS and AFBI join a €2million international project to monitor the effects of seaweed in the diet of pasture-based livestock. Seaweed will be added to grass-based silage on farm trials involving dairy cows in NI from early 2022.

IGFS lead Sharon Huws, said she expected the combined research to evidence a reduction in GHG emissions of at least 30%: “The science is there. It’s simply a matter of providing the necessary data and then implementing it," she said. "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," she continued. "I hope IGFS and AFBI research can soon provide the necessary data and reassurance for governments to take forward.”

Head of Agriculture at Morrisons, Sophie Throup, added: “As British farming's biggest customer, we’re very mindful of our role in supporting and inspiring the farmers we work with to help them achieve goals in sustainable farming.

“By supporting this research at Queen’s and AFBI, we are trialling this natural approach to reducing environmental emissions and improving the quality of beef products.”