Trials hope to cut cows’ methane emissions in fight against climate change

Experts are trialling a dietary supplement which aims to cut cows’ methane emissions – in the hope of reducing the dairy industry’s greenhouse gas output.

The University of Nottingham research, commissioned by supermarket giant Tesco and nature conservation organisation WWF, is using state-of-the-art monitoring equipment to assess the effectiveness of the supplement being added to cows’ normal diet.

Methane emitted by cows belching is being measured by sensors on food bins and milking stalls at the university’s farm in Sutton Bonington.

If successful, it is hoped the supplement could reduce methane emissions by as much as 30%.

Tesco and WWF formed a long-term partnership in 2018 with the aim of reducing the environmental impact of the average UK shopping basket by 50%, improving the sustainability of food while ensuring it remains affordable.

Tesco Agriculture Manager Tom Atkins said: “While many people might write off bovine emissions as an unchangeable fact of biology, we are confident that something can be done to at least reduce those emissions.

“The supplement has the potential to be rolled out in dairy herds across Tesco’s Sustainable Dairy Group, and help our farmers take further steps to improve the sustainability of the pint of milk you see on the shelves.”

Under the trial, each cow has a “digital tag” which records food consumption, milk production and, most importantly, methane output as she is milked.

The cows are divided into two groups, with one being fed their normal diet while the other is fed with the methane-reducing supplement in order to monitor the impact on their methane emissions.

The trials are being led by Phil Garnsworthy, professor of dairy science, who has worked at Nottingham University for more than 40 years.

He said: “What we’re looking to do by using the supplement is reduce the amount of methane the cows release. They’ll still need to belch, otherwise it’s not good for them.

“The supplement has a similar sort of effect to antacid used by humans. We take those because we have an upset stomach, but this supplement aids normal processes in the cow’s digestive system.

“It’s more like eating a live yoghurt to improve your gut microbes, but this supplement discourages the bacteria in the cow’s gut from producing methane.”

Sean Mallon, climate change specialist at WWF, said: “To tackle the problem of climate change, we need to change how we work and how our businesses operate. With innovation technology we can make our current food systems more efficient or less impactful.

“We want to make it easier for everyone to access an affordable and healthy diet. And we don’t think it has to cost the earth to do it.”

The results of the trial will be known later this month.

A UN report released in May said swift action to cut methane pollution would rapidly reduce the rate of global warming, while boosting health and food production.

Methane, which also comes from sources including fossil fuel extraction, is a short-lived but very potent climate pollutant that is second only to carbon dioxide in driving global warming.