It’s suppression A hot morning in the yard, even in the shade of the tall outdoor structure where the cows come to feed. On a typical farm, they would gather around a small basin, but here at UC Davis, they eat from special blue bins, which detect when and how much each one eats. It’s like Weight Watchers, the researchers here are just not so much interested in the shapes of these cows, but how much they burp.
Zoologist Frank Mitlohner leads me to another type of feeder, one that can easily be mistaken for a miniature loggerhead. He grabs a handful of alfalfa pellets that the machine dispenses when it detects that a cow has been stabbed in the head. “It’s like candy to them,” says Mitloner. I stick my head in the machine as Mitlohner points to a small metal tube inside: “This probe measures the methane they exhale, and this happens every three hours for all the animals in this study.”
Cows, you see, have a serious emissions problem. To digest tough plant matter, the cavernous stomach acts as a fermentation vessel. They are teeming with methanogenic microbes that process cellulose to produce volatile fatty acids, which the cows convert into meat and milk. But these methanogens also produce methane, a Especially bad greenhouse gases It is 80 times more powerful than carbon dioxide, thanks to the way its molecules vibrate to absorb infrared radiation. These gases capture heat, and that means more global warming.
“Methane is a by-product — an unintended consequence, I would say — of ruminant animals’ unique ability to digest cellulose,” says Miltoner. But just because cows can eat it doesn’t mean it’s easy for them. Since the plants that cows eat are nutritionally poor, the animals have to eat a lot of food to survive, periodically returning it from their four stomachs to ruminate again – this “ruminates”. This leads to constant belching or, as scientists call it, intestinal emissions.
Now multiply those burps at the world’s massive cattle population. To satiate mankind’s endless appetite for beef and milk, a billion head of cattle Now roaming the planet. a paper Published in September in the magazine nature foods By an international team of researchers it was found that the global food system generates a staggering 35 percent of total greenhouse gas emissions. Beef is responsible for a quarter of those food emissions, with another 8 percent coming from milk production.
However, methane only lasts a decade in the atmosphere, while carbon dioxide lasts for centuries. If scientists could figure out how to get cows to stop burping so much, that would dramatically reduce emissions, and we’d see the climate effects almost immediately. So Mitloehner and other researchers are experimenting with food additives such as seaweedAnd garlic and even essential oils derived from plants such as coriander seeds, which modify the environment of animals’ guts in various ways, for example by disrupting enzymes that produce methane. They also manipulate biochar — which is essentially coal — that absorbs methane in the gut.
That’s why Mitloehner does his best to estimate the diet of his cows: By using high-tech vats and methane detectors to dispense snacks, he can show how well a particular technology can reduce intestinal emissions. “We’ve found that depending on the additive you’re dealing with, we can reduce intestinal emissions anywhere between 10 to 50 percent, which is exciting,” Miltoner says.