Ben & Jerry's Puts Cows on a Special Diet to Curb Methane Emissions

Adding a small amount of seaweed to their feed reduces cows' burps by 80%.

Ben & Jerry's cookie dough ice cream

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Ice cream maker Ben & Jerry's is putting its dairy cows on a special diet to curb greenhouse gas emissions. The company announced on May 9 that it plans to give cows a seaweed supplement that will make them less prone to burping—and emitting climate-warming methane into the atmosphere. Ben & Jerry's referred to it in a press release as "Project Mootopia."

The supplement, called Brominata, is a dehydrated form of farmed red seaweed (Asparagopsis taxiformis) that has been shown to reduce methane emissions from cows' burps by up to 80%. Various feed additives have been experimented with in recent years, including lemongrass, garlic, and synthetic ingredients, but none has proven as effective as seaweed, even in very small quantities (0.3%). 

Ben & Jerry's offered some background on how cows' digestive tracts work:

"All ruminants (like cattle, sheep, deer, and goats) have a four-chambered stomach. The rumen is the largest compartment and can hold up to 25 gallons of food! Microbes in the rumen work to break down that food, and this fermentation produces carbon dioxide and methane. Digestion can produce up to 50 quarts of gasses an hour in the rumen, and a cow releases most of that gas by belching."

Certain feed additives can reduce the amount of gas in the rumen by inhibiting the microorganisms that create it. Less gas in the cow means less gas leaving the cow—and fewer emissions. And the benefits don't stop there: Belched methane is lost energy, which means that if a cow can retain it, it actually needs less food to create the same amount of milk—a win-win situation for the climate and the farmer.

Project Mootopia will roll out initially to 15 farms across the U.S. and the Netherlands. The cows will be monitored and studied, and all findings will be made public to benefit the entire dairy industry. The company hopes that by 2024 these farms will emit half the industry average for greenhouse gas emissions.

dairy cows eating feed

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Jenna Evans, global sustainability manager for Ben & Jerry's, said, "We believe in using the power of our business to create positive change. The fact that Brominata is effective in small quantities and easy for farmers to use makes it both environmentally and economically sustainable. We couldn't be more excited to be an early adopter and to join other businesses in ushering in a new era of sustainable dairy."

Brominata, which was recently approved for commercial use by the California Department of Food and Agriculture, is grown in land-based tanks in Hawaii and San Diego by a company called Blue Ocean Barns. Two other dairy companies—Straus Family Creamery and Clover Sonoma—have also signed deals with Blue Ocean Barns to add Brominata to their cows' feed, both with the goal of reducing climate impact.

Since an estimated one-quarter of global methane emissions come from cows, this is a sector where improvements like this could make a real difference. Methane is a greenhouse gas 80 times more powerful than carbon dioxide in the two decades following its release, so we have to get serious about tackling it if we want, as Ben & Jerry's put it, "a habitable world, let alone one where people can still enjoy ice cream." 

We do want ice cream. We always want ice cream! So this is happy and heartwarming news.

View Article Sources
  1. Roque, Breanna M., et al. "Red Seaweed (Asparagopsis Taxiformis) Supplementation Reduces Enteric Methane By Over 80 Percent In Beef Steers." PLOS ONE, vol. 16, no. 3, 2021, p. e0247820., doi:10.1371/journal.pone.0247820

  2. Searchinger, Tim, et al. "Opportunities to Reduce Methane Emissions from Global Agriculture." Princeton University, 2021.

  3. "Food Production is Responsible for One-Quarter of the World’s Greenhouse Gas Emissions." Our World in Data.

  4. "Methane Management." United Nations Economic Commission for Europe.