Reducing Emissions: a Sweet Breath of Fresh Air05 June 2009
US - Chewing her cud on a recent sunny morning, Libby, a 1,400-pound Holstein, paused to do her part in the battle against global warming, emitting a fragrant burp.
Libby, age 6, and the 74 other dairy cows on Guy Choiniere’s farm here are at the heart of an experiment to determine whether a change in diet will help them belch less methane, a potent heat-trapping gas that has been linked to climate change, writes Leslie Kaufman for the New York Times.
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.
According to the New York Times, as of the last reading in mid-May, the methane output of Mr. Choiniere’s herd had dropped 18 per cent. Meanwhile, milk production has held its own.
The program was initiated by Stonyfield Farm, the yogurt manufacturer, at the Vermont farms that supply it with organic milk. Mr. Choiniere, a third-generation dairy herder who went organic in 2003, said he had sensed that the outcome would be good even before he got the results.
“They are healthier,” he said of his cows. “Their coats are shinier, and the breath is sweet.”
Sweetening cow breath is a matter of some urgency, climate scientists say. Cows have digestive bacteria in their stomachs that cause them to belch methane, the second-most-significant heat-trapping emission associated with global warming after carbon dioxide. Although it is far less common in the atmosphere than carbon dioxide, it has 20 times the heat-trapping ability.
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