Scientists Feed Seaweed to Cows to Try to Reduce Methane Emissions

September 1, 2018 Updated: September 1, 2018

DAVIS, California—University of California researchers are feeding seaweed to dairy cows in an attempt to reduce the cattle’s effect on climate change.

UC Davis is studying whether adding small amounts of seaweed to cattle feed can help reduce their emissions of methane, a greenhouse gas that’s released when cattle burp, pass gas or make manure.

In a study this past spring, researchers found methane emissions were reduced by more than 30 percent 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.

More studies will be needed to determine its safety and efficacy, and seaweed growers would have to ramp up production to make it an economical option for farmers.

Dairy Cows Milked at UC Davis Farm
In this image taken from video, cows are milked at a dairy farm at the University of California, Davis on June 8, 2018. (AP Photo/Terry Chea)

Dairy farms and other livestock operations are major sources of methane, a heat-trapping gas many times more potent than carbon dioxide.

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 percent from 2013 levels by 2030.

By Terence Chea

RECOMMENDED