(NaturalNews) Adding fish oil to the diets of cows and other ruminants may significantly reduce the amount of methane that the animals emit via belching or flatulence, according to a study conducted by researchers from University College Dublin and presented at a meeting of the Society for General Microbiology.
"The fish oil affects the methane-producing bacteria in the rumen part of the cow's gut, leading to reduced emissions," said researcher Lorraine Lillis. "Understanding which microbial species are particularly influenced by changes in diet and relating them to methane production could bring about a more targeted approach to reducing methane emissions in animals."
Methane is one of the most potent greenhouse gases known, trapping 20 times as much heat by volume as the more abundant carbon dioxide. Worldwide, more than one-third of all methane emissions come from the digestive processes of ruminant (cud-chewing) livestock, namely cows, sheep and goats. The U.S. Environmental Protection Agency estimates that 24 percent of U.S. methane emissions can be attributed directly to livestock flatulence.
Ruminants are able to digest fibrous material such as grasses and leaves largely due to the fermentation process that takes place in their guts. A byproduct of this fermentation is methane, which the animals then release as belches or flatulence. Growing concern over animal agriculture's global warming impacts has already led to suggestions that caps be placed on the number of ruminants that can be raised at any given time.
In the current study, researchers added 2 percent fish oil by weight to the regular feed of three cows, then measured the bacterial composition of their guts. They found that the number of methane-producing bacteria was significantly reduced on a fish oil diet, and predicted a 21 percent reduction in methane emissions from those animals.
Fish oils are high in omega-3 fatty acids, which have been linked to a number of health benefits including a reduced risk of cancer, cardiovascular disease and cognitive decline.