Irish Scientists have found that fish oils can reduce the amount of methane in cows’ fart – a finding that could help reduce the greenhouse gases that cause global warming.

Methane – or cows’ farts, to use a layman’s term – is a much more powerful greenhouse gas than carbon dioxide, being more effective at trapping heat within the atmosphere.

And because cows are particularly flatulent, they are a huge source of global emissions.

Over the course of a year, for example, 200 cows produce as much emissions in energy terms as driving a family car more than 100,000 miles.

But a team of scientists from University College Dublin have found that adding two per cent of fish oil to the animal's feed reduces the amount of methane the cows emit by around a fifth.

One of the researchers, Dr. Lorraine Lillis, speaking at a microbiology conference in the U.K., said these findings could help the agriculture industry cut emissions.

Lillis and her colleagues conducted a trial in which trial where three cows were fed a diet that included a fish oil rich in omega-3 fatty acids. These cows had their farts monitored, and the scientists found that they contained 21 percent less methane than cows who hadn’t been fed the fish oils.

"The fish oil affects the methane-producing bacteria in the rumen part of the cow's gut, leading to reduced emissions,” said Dr. Lillis.

"Understanding which microbial species are particularly influenced by changes in diet and relating them to methane production could bring about a more targeted approach to reducing methane emissions in animals."