Fish Oils Reduce Greenhouse Gas Emissions From Flatulent Cows


NGS photo by George F. Mobley

By including two percent fish oil in the diet of cattle, the amount of methane released by the animals can be reduced, experiments in Ireland have demonstrated.

“The fish oil affects the methane-producing bacteria in the rumen part of the cow’s gut, leading to reduced emissions,” says Lorraine Lillis, one of the University College Dublin researchers, in a news release issued today by the Society for General Microbiology. “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.”

More than a third of all methane emissions, around 900 billion tonnes every year, are produced by methanogen bacteria that live in the digestive systems of ruminants such as cattle, sheep and goats, according to the release. “By volume, methane is 20 times more powerful at trapping solar energy than carbon dioxide, making it a potent greenhouse gas.”

Approximately half of Irish agricultural methane emissions result from farm animals. There have been suggestions that, to help combat global warming, a cap be placed on the number of animals in animal production due to their methane production, the release added. “But with a reduction in methane levels through diet this may not be as necessary.”

Other benefits to animals of omega 3 fatty acids in fish oils have been well documented: helping the heart and circulatory system, and improving meat quality.

Related National Geographic News stories:

California Cows Fail Latest Emissions Test

New Zealand Tries to Cap Gaseous Sheep Burps

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