Scientists Trying a Cow Trick: Adding Seaweed to Feed

University of California researchers are feeding seaweed to dairy cows in an attempt to make cattle more climate-friendly, per the AP. UC Davis is studying whether adding small amounts of seaweed to cattle feed can help reduce their emissions of methane, a potent greenhouse gas that's released when cattle burp, pass gas, or make manure. Livestock operations are a major source of methane emissions. In a study this past spring, researchers found methane emissions were reduced by more than 30% in a dozen Holstein cows that ate the ocean algae, which was mixed into their feed and sweetened with molasses to disguise the salty taste.

"I was extremely surprised when I saw the results," said Ermias Kebreab, the UC Davis animal scientist who led the study. "I wasn't expecting it to be that dramatic with a small amount of seaweed." Kebreab says his team plans to conduct a six-month study of a seaweed-infused diet in beef cattle starting in October. Researchers worldwide have searched for ways to reduce cattle emissions with various food additives such as garlic, oregano, cinnamon, and even curry—with mixed results. If successful, adding seaweed to cattle feed could help California dairy farms comply with a state law requiring livestock operators to cut emissions by 40% from 2013 levels by 2030.

(More methane stories.)