A lot research is being conducted worldwide into the application of seaweed in this manner. And the NI team’s trials are timely given the pledges made at COP26 by the EU and the US to reduce agricultural methane outputs from ruminant livestock by upwards of 30% by 2030.
Early laboratory research at IGFS has shown promising results using native Irish and UK brown seaweeds.
Previous research in Australia and the US generated headline results – up to 80% reductions in methane emissions from cattle given supplements from a red seaweed variety. These red seaweeds grow abundantly in warmer climates; however, they also 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, said the researchers.
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, according to the IGFS team.
Following on from the lab work, feeding trials in cows on UK farms will begin next year.
One three-year project is being run, 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 sees the IGFS and AFBI join a €2m international initiative led by Irish agency, An Teagasc, that is aiming 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 Northern Ireland from early 2022.
As well as assessing methane emissions of the beef and dairy cattle, these projects will assess the nutritional value of a variety of homegrown seaweeds, their effects on animal productivity and meat quality.
IGFS researcher, Katerina Theodoridou, a lecturer in farm animal nutrition within the School of Biological Sciences at Queen’s, said the expectation for the trial work is a reduction in GHG emissions of at least 30%.
She said the team has been collecting various samples of local varieties of seaweed, and then using specific equipment in the lab to mimic the rumen environment, in order to investigate the efficacy of the seaweed against methane emissions. “We have also been doing quantification and characterization work on the bioactive compounds in the seaweed to determine safety as regards its application in the diet of cows.”
The team’s lab work to date has allowed them to select potential candidates for the feeding trials.
“There are different ways to incorporate the seaweed into the cattle feed and we are exploring the most optimal method,” she told us.
The research work forms part of the Queen's-AFBI Alliance – a strategic partnership between Queen’s University and AFBI to maximize science and innovation capacity in NI to meet global challenges, such as carbon-neutral farming.