Cows have a unusual digestive system in that when they eat, they regurgitate some food for extra chewing. That regurgitation produces methane, a potent greenhouse gas.
Researchers at UC Davis have found that when beef cattle eat a little bit of seaweed every day, they produce 82% less methane. They published their findings in the peer-reviewed scientific journal PLOS ONE.
Cows’ digestive methane make up less than 4% of the total greenhouse gas emissions in the U.S. Even so, PhD student Breanna Roque says every bit counts.
“Every industry needs to do their part in reducing overall emissions and providing for more sustainable practices,” Roque says. “I think that feeding seaweed provides this to farmers: to find a way to reduce their overall carbon footprint.”
Roque and UC Davis professor Ermias Kebreab initially started their research in 2018, when they were able to reduce methane from dairy cows by about 50% over a two-week period. They fed the cows a small bit of seaweed called asparagopsis armata, a red algae that inhibits an enzyme in the cow’s digestive system that contributes to methane production.
Their more recent study looked at whether they could sustain this reduction over a five-month period. This time they fed beef cattle some seaweed called asparagopsis taxiformis, another type of red algae.
Roque says this seaweed can be found all around the world. This type of seaweed can be found all around the world. Still, it could take a bit of effort to harvest it for cattle ranchers — and to transport it to them in a sustainable way. Kebreab and Roque hope to address these challenges in future studies.
