Cleaner Cow Burps to Tackle Climate Change

Cows are contributing to climate change in a big way. The methane produced when cows pass wind is one of the biggest drivers of a heating planetary atmosphere. However, a recent study claims to have found a means of reducing cattle methane emissions by 30 percent using an inhibitor molecule.

The study, published in July in Proceedings of the National Academy of Sciences (PNAS), tested the effect of 3NOP, a molecule that restricts the production of methane during enteric fermentation — the process of digestion by which ruminant animals like cows and sheep break down their food.

Researchers found that, as well as cutting methane production, the inhibitors had no negative impact on the quantity or quality of milk produced by lactating Holstein cows. In addition, cows which ate feed treated with the inhibitor gained on average 80 percent more body weight than the control cows.

The study indicates that chemical inhibitors could play an important role in cutting methane emissions and, as a result, tackling climate change. According to the U.N. Food and Agriculture Organisation, the livestock sector contributes 18 percent of global greenhouse gas emissions, including 35 percent of methane. The gas has 23 times the Global Warming Potential of carbon dioxide; livestock emissions are estimated to cause as much global warming as 2.2 billion tonnes of carbon dioxide.

Alexander Hristov, professor of dairy nutrition at Pennsylvania State University, says that though methane inhibitors have been known of for a while, this was the first study to concretely prove that they work over a persistent period of time—12 weeks, in this case—and do not negatively impact the amount of food eaten by the animal, milk production or the animal's digestive abilities.

"If enteric methane is a major contributor to greenhouse gas emissions and you are able to knock it off by 30 percent globally, the impact can be more than significant," says Hristov. However, he cautions that the inhibitor would require regulatory approval before it could be widely used, and even then farmers would need to see some financial incentive to use it.

Forty-eight cows were in the study and the cows' feed was treated with varying amounts of 3NOP. Ruminants such as cows have stomachs with multiple sections, including a rumen, where food is fermented by bacteria before being digested. It is here that methane is produced as a by-product of fermentation. Hristov says that the inhibitor does not stop cows from belching (or farting), but rather reduces the amount of methane in these emissions by blocking its production in the rumen. The energy saved from producing and emitting methane was stored as additional body weight, accounting for the dramatic increase in weight of cows which digested the inhibitor.

The inhibitor is produced and marketed as a feed additive by DSM, a Dutch company with 10 billion euros in annual sales—32 percent of which are in animal feed, according to the Washington Post. A DSM spokesman told Newsweek that, since the inhibitor was not yet on the market, it was not possible to give an estimate of production costs. The additive forms part of the company's 'Clean Cow' technology, which they claim could have a big impact on reducing the environmental impact of livestock emissions. However, it would need to undergo stringent safety tests before it could be implemented on a large scale. The Post reported that Francesco Tubiello, an expert with the FAO, said that the study should be extended over a full agricultural season in order to "fully assess impact on animals first of all as well as on products quantity and quality."