News of Arla's methane suppressing supplement trial has sparked debate, with the NFU admitting that 'questions remain' over the impact of long-term usage.
The dairy co-operative's new project will take place alongside retailers Morrisons, Tesco and Aldi, as well as thirty farms, which will trial feed additive Bovaer®.
Arla said the powdered supplement had the potential to reduce enteric methane emissions from cows on average by 27%.
The product can be added to animal feed and works by suppressing a cow's ability to produce methane during the digestive process.
Use of the additive has been given the green light in numerous countries, including Australia, Brazil and Canada, and was permitted for the UK in April.
Following the launch of the trial, the news has sparked significant debate on social media, with questions surrounding the product's environmental and health impacts.
The NFU has since responded, saying it was "clear that questions remain" over the use of methane suppressing supplements in the ruminant diet.
Since its inception, the union has played a role in the government-led roundtable on methane inhibitors, as feed supplements "could be one way to support sustainable food supply chains".
In October 2023, Defra renewed its commitment to reducing methane emissions in livestock through plans to encourage the use of methane suppressing feed products in England.
However, the NFU said that these products needed to "work in real-life situations" and be incentivised alongside other emission-reducing techniques, such as genetics and efficiency improvements.
NFU Dairy Board chair, Paul Tompkins said: “Questions remain about long-term efficacy, that it can be used practically and effectively on farm, and that animal health and welfare will not be impacted.
“Defra research has shown that shoppers are generally positive about methane-suppressing products if human and/or animal health are not affected.
"It’s critical we also have a strong evidence base to give farmers the confidence to use these products. This trial project between Arla, Morrisons, Aldi and Tesco could help provide this evidence.
“It’s important the supply chain and government continues to work together to enable informed decision-making on GHG emissions-reducing techniques.”