To fight climate change, scientists are putting sheep in burp machines

Valle del Cauca, Colombia — The interior looks a bit like a walk-in refrigerator. Located inside a research building in southwest Columbia, they are essentially large metal boxes with large latched doors. Inside there are concrete floors, plexiglass windows, and wall-mounted air conditioning.

These chambers serve the noble and highly scientific purpose of measuring burps and farts. Specifically, those produced by animals.

In the coming months, scientists from an agricultural research organization called the International Alliance for Biodiversity and CIAT (which built eight of the rooms) plan to place live sheep inside each room. Then wait for the animal to pass the gas. Over 24 hours, the gas passes through high-tech machines that measure its contents.

What exactly are they looking for? Among other things, methane.

These chambers are part of a multi-year project to reduce the amount of methane produced by livestock. This is important. Methane is a powerful greenhouse gas and is responsible for approximately 20-30% of global warming since the Industrial Revolution. Most of the world’s methane emissions come from human activities, with the largest single source being agriculture, the burps of ruminant animals such as cows, goats, and sheep and their manure.

The amount of methane produced by an animal is related to what it eats. And that is the key premise of the new CIAT project. Starting in February, researchers led by Jacobo Arango will feed sheep, which have digestive systems very similar to cows, a variety of plants, including legumes and grasses. They then put the animals inside the room, feed them more food, and measure the amount of methane they produce. The idea is to identify specific types of feed that lead to a reduction in greenhouse gases, with the ultimate goal of reducing global methane emissions and thereby combating climate change.

The researchers aim to test about 6,000 types of feed, many of which are stored as seeds in a gene bank at the CIAT research center near Palmira, Colombia. The bank, known as Future Seeds, houses approximately 67,000 samples, including the world’s largest collection of tropical forage plant seeds.

When I visited the bank one afternoon in October, it was so stuffy outside that I had to put on a winter jacket to go inside. Seeds are stored in a room at -9.4 degrees Fahrenheit in vacuum-sealed packages made from laminated aluminum foil. Inside the room, rows of seed packets were placed on portable shelves similar to those found in university libraries.

In the methane project, scientists use seeds collected from banks and grow them as feed. From there, the experiment has two main phases. The first is testing plant material in a laboratory that does not use animals. Basically, researchers recreate the stomach of a ruminant, such as a cow, in a test tube, put feed inside, and see how much gas is produced. Only plant varieties that produce little methane and meet other requirements regarding nutrition, drought tolerance, etc. are fed to sheep. They are placed in a room, at which point their burps, farts, and feces are measured.

Researchers may eventually bring cows into the lab as a final test, said Arango, a senior scientist at the International Alliance for Biological Diversity and CIAT.

Lab trials are currently underway and several feed varieties are already showing promise, Arango said. Most are legumes, such as Leucaena diversifolia, a plant species with feather-like leaves and spiky ball-like flowers.

There are many reasons why certain plants produce less methane. For example, some legumes are high in compounds called condensed tannins. Tannins, which are also found in wine and give red wine its astringent taste, can inhibit microorganisms that produce methane in the intestines of cows.

Burp detector against climate change

Without addressing emissions from the food sector, it will be impossible to limit global warming to 1.5 degrees Celsius, beyond which climate change will be catastrophic. Reducing meat consumption (particularly beef) is perhaps the most important part of that effort, but this will be an uphill battle as global meat consumption is predicted to increase in the coming years.

That’s why identifying better feeds is at least a promising tool for mitigating the climate impacts of carnivores, said Richard Waite, director of agriculture initiatives at the World Resources Institute, a research group. He said it would be. A review published in 2022 found that by making various changes to livestock diets, such as feeding them tannin-rich foods, they could reduce the methane they produce daily by an average of 20 percent without reducing the amount of milk or meat they produce. It was found that it was possible to reduce the amount by more than yield.

High-tech approaches to reducing methane from livestock are already under development, from feed supplements to vaccines that reduce methane levels. However, it is not yet clear whether enough farmers, many of them in developing countries, will want to adopt these approaches or be able to pay for them.

The advantage of the new CIAT project is that it is simple and useful for farmers in poorer regions of the world, where beef consumption is growing rapidly. The idea is to identify different feeds that can help farmers reduce methane emissions in their cow pastures, Arango said. It’s also a way to add plant diversity to your meadow landscape, which comes with other benefits, such as increased wildlife habitat.

After all, measuring the amount of gas emitted by sheep may sound like a joke, but it’s serious science, said Waite of the World Resources Institute. “It’s funny because it’s burps and farts (mostly burps), but it’s really important,” Waite said. “That’s a lot of emissions. So anything we can do to reduce those emissions while still feeding more people will really help.”

Kenny Torrella contributed reporting.