Omega-3's in a Cow's Diet Provide a Health Boost—to the Atmosphere

By Eliza Strickland | June 8, 2009 10:38 am

cowsIt’s not just humans who can take part in combating global warming–cows can play a role, too. Scientists say that the methane belched up by cows is a significant source of the greenhouse gas, and are searching for ways to reduce these burps. The digestive bacteria in the cows’ stomach produces the methane, which is the second-most significant gas (behind carbon dioxide) driving global warming. While methane is much less prevalent in the atmosphere than carbon dioxide, it traps heat 20 times more efficiently than carbon dioxide.

Researchers are examining a variety of tactics, including breeding or genetically engineering cows that belch less, or adjusting the bacterial mix in cows’ stomachs. But altering the cows’ feed has shown the most promise thus far. Since January, cows at 15 farms across Vermont have had their grain feed adjusted to include more plants like alfalfa and flaxseed — substances that, unlike corn or soy, mimic the spring grasses that the animals evolved long ago to eat. As of the last reading in mid-May, the methane output of [one test] herd had dropped 18 percent. Meanwhile, milk production has held its own [The New York Times].

Researchers say the spring grasses that cows ate for millions of years are high in omega-3 fatty acids, which may help the cows’ digestive tracts operate smoothly. In contrast, the corn and soy feeds that factory farms rely on to quickly fatten their cattle have a different fatty acid structure, which causes more methane production.

The trial in Vermont was spearheaded by the yogurt company Stonyfield Farm, which buys its organic milk from Vermont farms. Researchers say that if the test results influence large-scale industrial farms, the impact could be significant. Air quality expert Frank Mitloehner, who places cows in air-tight tent enclosures and measures what he calls their “eruptions,” says the average cow expels — through burps mostly, but some flatulence — 200 to 400 pounds of methane a year [The New York Times].

Related Content:
80beats: Cow Genome May Allow Farmers to Breed a Better Milk Cow
DISCOVER: All Aboard the Cow Train explains how cow pies can be turned into fuel
DISCOVER: 10 Ways Methane Could Brake Global Warming–or Break the Planet

Image: flickr / macieklew

CATEGORIZED UNDER: Environment, Living World
  • skinman

    Corn growers won’t be happy with this news.

  • FILTHpig

    “Air quality expert Frank Mitloehner, who places cows in air-tight tent enclosures and measures what he calls their “eruptions,” says the average cow expels — through burps mostly, but some flatulence — 200 to 400 pounds of methane a year.”

    If I get laid off (hopefully not), I know which job I WON’T be seeking.

  • Nick

    Oh, wow! Imagine that, feeding a cow something it’s spent millions of years evolving to eat is BETTER for it than the cheap corn our government subsidizes with our tax dollars?

    P.S. Re: Skinman corn growers are mostly payed in subsides from our government. Why would they care, they get paid whether or not cows eat the corn.

    And hey, it doesn’t matter if this research influences large-scale factory farms … there are so many other problems with factory farming of animals the methane-based pollution is one the least of them. The lakes of cow and pig shit that contaminate our groundwater…

  • YouRang

    Surely methane producing bacteria isn’t normal flora. Surely there are natural herbs that can do an even better job.

  • elgatoso

    Use the corn to make plastic,use the cow and pig manure to make biofuel and subsidise alfalfa and flaxseed.

  • Diet

    It is really surprise to know the role of cows in combating the global warming.

  • Melissa

    Not only is feeding cattle what they normally eat beneficial to the environment, it is also much healthier for us. Do we really need a study to tell us this?

    So it should be a win-win to let cattle graze on grass. But it just isn’t as profitable, so we don’t do it.

    People need to realize that really cheap beef is available to us because cows are being fed corn, grains, and leftover junk food. Yes junk food. I’ve seen videos of farmers feeding their cattle reject potato chips and candies. Why? Because it was cheap and readily available.

    Yes, grass-fed beef is more expensive, but it is better for us and the environment. There are ways to save substantially on it though, by buying larger amounts from local farmers and storing it in the freezer.

    Check out my site, and this particular page, for more information on grass-fed beef benefits:

  • Stacy

    I’ll check this out again.


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