Reducing the Carbon Hoofprint: A Look at Cow Methane Emissions
Georgia Udall | November 24, 2021
Special to The Echo | Georgia Udall
A single cow emits around 220 pounds of methane per year, mostly through burps.
There’s nothing more serene than the image of a cow standing in a pasture and munching on grass. After all, cows are familiar and well-loved creatures in western society. However, they contribute to global warming in an unexpected way. Recently, innovative ways to combat this problem have come to light.
Cows are ruminants, meaning they gain nutrients by fermenting food in their four stomachs. Symbiotic microorganisms, including bacteria, live in the rumen, which is the largest stomach compartment and where the food first goes. These microbes break down plant matter throughout the cow’s digestion, and some of the byproducts of this process, called enteric fermentation, are carbon dioxide and methane. When cows burp, these greenhouse gases are released into the atmosphere.
Due to the growing beef and dairy industries, cows have become a major source of methane emissions. According to the EPA, about 10 percent of greenhouse gas emissions in the US come from agriculture. On top of that, methane is 28 times more potent than CO2. There are about 1.4 billion cows on Earth right now, so that’s a lot of cow burps.
Langdon Martin, Ph.D., a chemistry professor at Warren Wilson College (WWC), has been involved in some research about adding spent brewer yeast, a byproduct of beer production, to the rumen of cows in order to reduce the effects of their methane production.
“Methane production is probably not something we could completely stop, but if we could lower it, that would do a lot for reducing global warming,” Martin said.
It is a large issue to tackle, and the possible solution at hand may seem unassuming — beer. Asheville, which is known as one of the “beer cities” of the U.S., has plenty of breweries to provide resources. When beer is brewed, the spent brewer’s yeast is removed at the end of the mass fermentation process.
In this research project, Langdon and his partners added the spent yeast to rumen fluid collected from several cattle, some of which were from WWC. Their results showed that the antimicrobial properties of the spent yeast reduced the methane and ammonia that were previously being leaked into the atmosphere. This approach kills two birds with one stone; it uses a product that might otherwise be wasted to diminish the harmful impacts of global warming.
When it comes to reducing environmental impact at WWC, all farm animals are included. Kassidy Stoneburg, who is the pig boss and a senior at WWC, gets to watch the pigs enjoy their eco-friendly bedding, which also comes from nearby breweries.
“We’ve definitely used old or stale hops from local breweries as pig bedding,” said Stoneburg. “It’s soft, keeps them warm. And they love it.”
Some farmers are taking matters into their own hands and coming up with other innovative ways to reduce these methane emissions. One especially original idea was attempted by researchers in Germany. They figured out how to “potty-train” cows by giving them treats when they used a certain area to urinate where their waste could be contained and treated. Other potential solutions include feeding cows seaweed or various special feed additives and even giving cows a vaccine that fights off the microbes that produce methane.
Beer, potty training, and seaweed: the possibilities are endless! With all of the research going into the mitigation of climate change, on global and local scales, it will be a surprise what solutions emerge next. To learn more about Langdon Martin’s research, join him for a talk at 4 p.m. on Monday, November 29 in Boon.
