Cows burp throughout the day as they digest food. And it’s not just an affront to Miss Manners. Their burps contain methane, a greenhouse gas that’s more potent than carbon dioxide. So the perpetual belching contributes to global warming.

But new research suggests that an ingredient from the deep blue sea could help reduce these bovine emissions.

Ermias Kebreab of the University of California-Davis says certain varieties of seaweed contain a compound that inhibits methane production.

He led a recent experiment with 12 cows to see whether feeding cows seaweed, mixed in with normal feed, could reduce the animals’ methane emissions.

Kebreab: “Seaweed is a little bit salty, so what we do is we cut it with molasses and then we mix it very well by hand and with a pitchfork to make sure that they’re not able to pick it out.”

His team found that adding just a tiny amount of seaweed cut the methane content of the cows’ burps by about half.

He says more research is needed before seaweed becomes a staple ingredient on dairy farms. But these early results suggest that adding seaweed to cows’ diets could be a strategy for reducing methane pollution around the world.

Reporting credit: Sarah Kennedy/ChavoBart Digital Media.

Diana Madson

Diana Madson contributed regularly to Yale Climate Connections from 2014 to 2021. She enjoys exploring U.S.-based stories about unexpected and innovative solutions to climate change. In addition to her...