Genetically-Engineered Cows: Do Less Burps Mean a Greener Planet?

Humans in recent decades have developed a routine in genetically modifying nature, from the infamous Flavr Savr Tomatoes to the more successful corn crop, through a process of directly modifying genes using genetic engineering. Genetic engineering has a long history, starting centuries and centuries ago with selective breeding. Animals like dogs would be purposely placed together or separated based on what the breeder desired. Food entered the scene in ancient times when farmers, believed to be in the Middle East and Northern Africa, began selectively breeding wheat for their needs, in a process now called domestication. 

Food that has been genetically modified is now called GE food (genetically-engineered foods) by the Food and Drug Administration but many people also know the term GMO, meaning genetically-modified organisms and which refers to plants and animals alike. 

This past July, researchers from across the world published a report in Science Advances proposing a potential solution to help save our environment from the massive amounts of methane entering our atmosphere: genetically modifying cows to release less methane (CH4) in their burps and other bodily gases. 

Image via EPA

According to the Environmental Protection Agency (EPA) in the US, through the analysis of emissions data for 2017, ten percent of greenhouse gas emissions in this country come from methane. Almost 25 percent of the methane produced in the United States comes from cows. While methane is released less than carbon dioxide, it is more potent than CO2, and therefore researchers are constantly looking for ways to lower emissions from in the livestock and agricultural industry. 

Image via EPA

But how do livestock like cows fit into the greenhouse gas discussion? It’s all about the rumen, my friends. 

Rumen (noun): the first stomach of a ruminant, which receives food or cud from the esophagus, partly digests it with the aid of bacteria, and passes it to the reticulum. 
Image via CSIRO

This part of the body, found in ‘ruminant’ animals like cows, fascinates microbiologists with the complex bacteria communities it hosts which work to digest food like grass and provide necessary nutrients to the animal that consumes that grass. Humans rely on ruminants like cows for milk and meat and therefore are vital to our food chain and ecosystem. However in their report this July, a collection of 33 scientists discussed the environmental ramifications of the effects of the rumen digestive system, mainly paving the way for future research by providing foundation evidence that cows can be genetically modified to produce less methane through the manipulation of the bacteria in their bodies. 

According to Christine Baes, an author of the study, in an article for CBC News, “We can actually select animals that have the right DNA that don’t produce much methane and that more efficiently use their feed.” 

By studying over a thousand animals, particularly 816 Holstein dairy cows in the UK and Italy and 200 Nordic Red dairy cows in Sweden and Finland, they conclude that dairy cows can be selectively bred to “provide a sustainable solution to increase efficiency and lower emissions from ruminant livestock”. They identified the bacteria community that produces methane in cows, and through this identification, assert that this bacteria can be bred to have cows that burp less methane. While this type of breeding may be a hard sell for farmers and producers because it doesn’t increase milk production or have any other economic benefit, the environmental benefit might just be worth it. 

In an article for Newsweek, John Wallace, an author of the study, explained, “We know of no downside to lowering methane emissions in this way. However, there is no upside either — except for the environment.” He continued, “Our alternative strategy would be to use our data to breed for improved feed-to-milk efficiency using the microbiome as selection trait. That would lower emissions too.” 

Some authors of the study suggest a monetary incentive to convince farmers to breed their cows for these environmental benefits, but this has yet to happen. 

Find out more about the selective breeding of cows at National Geographic in this article by Sarah Gibbens! 

Catie Brown

Although I’ve always loved writing, I embarked on my journey into science journalism about three years ago. I am fascinated by all things water — oceans, ice, coral reefs, currents, extreme weather, sanitation, energy, and (of course!) climate change. I also love looking into the different ways we talk about climate change as a social, cultural, economic, spiritual, and political crisis. Big thanks to coffee and chemistry jokes for keeping me going. Happy reading!