Feeding Beer Waste to Cows Reduces Methane Emissions, Study Shows

We drink the beer. The cows eat the waste. Everyone is happy.

Cows produce significant amounts of methane—a greenhouse gas that contributes to global warming. But researchers in Belgium believe they may have discovered a way to reduce these environmentally unfriendly cattle burps… beer. No, not getting the cows drunk: That’s not how Belgians get their kicks. Instead, a recent study determined that cattle feed that includes spent grains—a byproduct of the brewing process—as one of its key ingredients could lower these methane levels by as much 13 percent.

The Flemish Institute for Agricultural, Fisheries and Food (IVLO), which was behind the study, said that, after years of research, they’ve determined that these spent grains, containing mainly the leftover chaff and proteins from barley, were the key to cutting the methane emissions from cattle digestion by between 11 to 13 percent. However, the benefit only occurred when combined with rapeseed meal—which itself is a byproduct of producing rapeseed oil. “If we only add spent grains to the feed, there is no less methane,” Sam De Campeneere, scientific director of the Animal Department at ILVO, said announcing the results. “We cannot yet explain why that is so.”

A cow eating grain from a trough
Bloomberg Creative Photos/Getty Images

Additionally, upcycling spent grains—which often go to waste—into cow feed comes with other benefits. “By using these byproducts, no other raw materials, such as extra soy, need to be mixed into the feed either,” De Campeneere continued. As a result, by reducing the use of soy—which comes with its own ecological footprint—and using beer waste from one of Belgium’s many breweries instead, “the ecological footprint of a liter of milk fell by no less than 31 percent,” he concluded.

Meanwhile, Raf Nagels—a Belgian dairy farmer whose cows were involved in the study—went so far as to say his cows even enjoyed the environmentally-friendly feed. “The cows like to eat the spent grains,” he told ILVO. “Better for the cow and better for the environment: a win-win, therefore.”

Don’t forget the humans. We get to drink the beer. It’s a win-win-win!

Was this page helpful?
Related Articles