It is oppressive Hot mornings in the barnyard, even in the shade of the long structure of the open sky where the cows come to feed. On a typical farm, they would gather around a hole, but here at UC Davis they release from a special blue pond, which identifies when and how much everyone eats. It’s like weight watchers, here not only are researchers so interested in the statistics of these cows, but also how much they break down.
Zoologist Frank Mitlohner took me to another type of feeder, which could easily be mistaken for a tiny wooden chip. He grabs a handful of alfalfa shells which the machine detects when a cow pokes its head off. “It’s like sweet to them,” Mitlohner says. I stuck my head in the machine because Mitlohner pointed a small metal tube inside it: “This probe measures the methane generated by them and for all the animals in this study it happens every three hours.”
Cows, you see, have a serious emission problem. In order to digest hard plant material, their hollow stomach fermentation acts as a vat. They produce methanogen, a bacterium that processes cellulose to form volatile fatty acids, which are converted into beef and milk. But those methanogens also produce methane, especially the nasty greenhouse gas that is times0 times more powerful than carbon dioxide, thanks to the vibrations of its molecules to absorb infrared radiation. These gases contain heat, and this means more global warming.
“Methane is a by-product – an unintended consequence, I would say – of the unique ability of ruminant animals to digest cellulose,” Mitlohner said. But being able to eat cows does not mean that it is easy for them. Since the plants that the cow eats are nutritionally poor, the animals have to eat a lot of food to survive and are periodically brought back from four stomachs to wake it up again – this is called “chuda chewing.” It is a persistent rash or, as scientists call it an enteric discharge.
Now multiply that barbaric by the huge cattle population of the world. To satisfy humanity’s abysmal hunger for beef and milk, billions of cattle are now roaming the earth. A paper published in the journal in September Nature is food An international team of researchers found that the global food system accounts for 355 percent of total greenhouse gas emissions. Beef is responsible for one-fourth of this food migration, the other 8 percent comes from milk production.
However, methane lasts in the atmosphere for about a decade, while carbon dioxide lasts for centuries. If scientists can find a way to stop so many cows from belching, it will have a big impact on emissions and we will see the effects of climate almost immediately. So Mitlohner and other researchers are experimenting with essential oils derived from plants such as seaweed, garlic and even coriander seeds, which tweak the intestinal environment of animals in a variety of ways, for example disrupting methane-producing enzymes. They are also playing with biochar-charcoal, which basically keeps methane in the gut.
This is why Mitlohner is going so far as to measure his cow’s diet: using high-tech trout and snack-dispensing methane detectors, he can show how well a particular technique can reduce enteric emissions. “We’ve seen that, depending on what additive you’re working on, we can reduce enteric emissions anywhere by 10 to 50 percent, and that’s exciting,” Mitlohner said.