Scientists aim to fight climate change by stopping cow burps with seaweed and genetically modified microbes
Researchers in California are developing a pill to alter cows’ gut bacteria so they emit less methane, a dangerous greenhouse gas.
Scientists are exploring the use of seaweed to reduce methane emissions from cow burps and tackle climate change. Photo: Shutterstock A scientist guides a long tube into the mouth and down into the stomach of Thing One, a two-month-old calf that is part of a research project aiming to prevent cows from burping methane, a potent greenhouse gas.
Paulo de Meo Filho, a postdoctoral researcher at the University of California, Davis (UC Davis), is part of an ambitious experiment to develop a pill to transform cow gut bacteria. They hope to make cows emit less methane – or even none at all.
While the fossil fuel industry and some natural sources emit methane, cattle farming has become a major climate concern due to the sheer volume of the cows’ emissions.
“Almost half of the increase in [global] temperature we’ve had has been because of methane,” said Ermias Kebreab, an animal science professor at UC Davis.
Methane is the second largest contributor to climate change after carbon dioxide (CO2). Although it breaks down faster than CO2, it is more potent.
“Methane lives in the atmosphere for about 12 years, unlike carbon dioxide, which persists for centuries,” Kebreab said. “If you start reducing methane now, we can actually see the effect on the temperature very quickly.”
Filho uses the tube to extract liquid from Thing One’s rumen – the first stomach compartment containing partially digested food (see graphic).
Using the rumen liquid samples, the scientists are studying the microbes that convert hydrogen into methane, which is not digested by the cow but instead burped out. A single cow will burp roughly 220 pounds (100kg) of the gas annually.
Thing One and other calves receive a seaweed-supplemented diet to reduce methane production. Scientists hope to achieve similar results by introducing genetically modified microbes that soak up hydrogen, starving methane-producing bacteria at the source.
However, the team is proceeding with caution.
“We cannot simply cut down methane production by removing methane-making bacteria, as hydrogen could accumulate to the point of harming the animal,” warned Matthias Hess, who runs the UC Davis lab.
“Microbes are kind of social critters. They really like to live together. The way they interact and affect each other impacts the overall function of the ecosystem.”
Hess’s students test different formulas in bioreactors, vessels that reproduce microorganisms’ living conditions in a stomach from movements to temperature.
The project is being carried out at UC Davis, as well as UC Berkeley’s Innovative Genomics Institute (IGI).
Should lab-grown meat replace traditional animal farming?
IGI scientists are trying to identify the right microbe to genetically alter to supplant methane-producing microbes.
The ultimate goal is a single-dose treatment administered early in life since most cattle graze freely and cannot receive daily supplements.
Kebreab has long studied sustainable livestock practices and pushes back against calls to reduce meat consumption to save the planet.
While acknowledging this might work for healthy adults in developed nations, he pointed to countries like Indonesia, where the government is seeking to increase meat and dairy production because 20 per cent of children under five suffer from stunted growth.
Are cows the only animals that burp methane?
Cows belong to a group of animals called ruminants. Ruminants are mammals that have a complex digestive system with multiple stomachs.
They are known for digesting rigid plant material like grass and hay.
They do this by regurgitating partially digested food called “cud” and chewing it again.
Ruminants have multi-chambered stomachs and undergo a similar digestive process called enteric fermentation, producing methane.
Other examples of popular ruminant livestock include sheep and goats. Of these three, cows produce the most methane.