A way to reduce methane from cows lies in selective breeding

A fully grown cow produces anywhere between 70kg and 120kg of methane gas, depending on variables like its diet. Methane is a greenhouse gas that is 23 times more potent than CO2 when it comes to its effects on the climate. There are 1.5 billion heads of cattle on the planet.

You do the math.

Cattle, and other ruminants, contribute well over a third (37%) manmade methane emissions and one way to reduce those massive emissions is to reduce the number of cows. That’s easier said than done, though, because entire industries depend on cattle in numerous countries and people worldwide love beef and milk products.

An international team of scientists has another solution: selective breeding.

They conducted a study of 1,000 dairy cows in four European countries to find out how ruminant microbiomes can be controlled in host animals in order to reduce flatulence and thus methane emissions.

“What we showed is that the level and type of methane-producing microbes in the cow is to a large extent controlled by the cow’s genetic makeup,” says Prof. John Williams, an expert at the University of Adelaide’s School of Animal and Veterinary Sciences who was a coauthor of the study.

“That means we could select for cattle which are less likely to have high levels of methane-producing bacteria in their rumen,” he adds.

To gain a comprehensive image, the researchers analyzed the microbiomes, via fluid samples, of those 1,000 cows. They also measured their feed intake, milk production, methane emissions and other biochemical characteristics. The idea is that we could select cows for breeding that produce less methane so that their offspring will do so too.

“Previously we knew it was possible to reduce methane emissions by changing the diet,” Williams explains. “But changing the genetics is much more significant – in this way we can select for cows that permanently produce less methane,” he adds.

Having said that, the most effective way to reduce methane emissions on a large scale still lies in transitioning to a less beef-based diet worldwide. That, and in ceasing to destroy further forests to make way for new pastures, especially in heavily forested areas like the Amazon.