Quick Summary
- Adding seaweed to cattle feed may significantly reduce methane emissions from dairy cows
- Method could help dairy farmers meet new state methane-emissions standards
- The °”TV project is first in the world to test seaweed on live dairy cattle
Seaweed may be the super food dairy cattle need to reduce the amount of methane they burp into the atmosphere. Early results from research at the University of California, Davis, indicate that just a touch of the ocean algae in cattle feed could dramatically cut greenhouse gas emissions from Californiaâs 1.8 million dairy cows.
âThis is a very surprising and promising development,â said animal science professor and Sesnon Endowed Chair Ermias Kebreab inside the °”TV dairy barn where he is testing seaweed efficacy with 12 Holstein cows. âResults are not final, but so far we are seeing substantial emission reductions. This could help Californiaâs dairy farmers meet new methane-emission standards and sustainably produce the dairy products we need to feed the world.â
Kebreabâs project is the first to test seaweed on live dairy cattle anywhere in the world.
His team will publish preliminary findings in late June and begin further tests with additional cattle later this summer.
A question of digestion
Cows and other âruminantâ animals like goats and sheep burp continuously throughout the day as they digest food in their rumen, the first of four sections of their stomachs. The rumen is home to millions of microbes that help ferment and break down high-fiber food like grass and hay. This fermentation produces gases that combine to form methane, an especially potent heat-trapping gas.
So, as cattle perpetually burp and exhale, they emit methane. Cows also pass methane gas from the other end, but to a much lesser degree. Manure, too, is a source of methane emissions.
In an , California legislators recently adopted regulations requiring dairy farmers and other producers to cut methane emissions 40 percent by 2030.
âSince much of a dairyâs methane emissions come from the animal itself, nutrition can play a big role in finding solutions,â said Kebreab.
Molasses, please
Testing supplements in cattle feed is not new. Kebreab and his colleagues at °”TV and beyond are finding varying degrees of success with a wide range of feed additives. Some compounds work in the lab with simulated cattle digestive systems, but not with live animals. Researchers in England, for example, found success with curry supplements until they tested it with live cattle.
âThe cows didnât like the curry,â Kebreab said.
During lab tests last year, researchers in Australia found that just 2 percent seaweed in cattle feed could reduce methane emissions by 99 percent. The seaweed apparently inhibits an enzyme that contributes to methane production.
Judging from the reaction of the °”TV cows, the seaweed is so far, so good â especially when cut with a bit of molasses.
âThe molasses masks the smell,â Kebreab said, smiling as two Holsteins nudged a gate that opens when itâs time for their next meal. âThey enjoy their feed.â
To test seaweed efficacy, Kebreab and animal nutrition graduate student Breanne Roque have separated 12 cows into three groups. Two groups are fed with different doses of seaweed, and one groupâs feed has no seaweed at all. They rotate through the two-week feeding regimens with a weeklong seaweed fast in between.
Four times a day, cows get a snack from an open-air contraption that measures the methane in their breath as they eat the treat.
âThe numbers weâre seeing are amazing â well beyond the target that farmers will need to reach,â Kebreab said.
Throughout the seaweed diet, the cowsâ milk is tested for qualities like yield, flavor and nutritional content.
A love of milk
Sustainable dairy production is not just an academic endeavor for Kebreab. He has loved milk since he was a young boy growing up in Eritrea, a country in the Horn of Africa.
âI was always amazed at how an animal that eats grass can produce such a high-quality food,â Kebreab said. âAnd I loved the taste. We didnât get that much â maybe once or twice a week. I wondered, can we find a way to produce enough milk for everyone?â
Kebreab is trying. Among his many projects, Kebreab recently received a $500,000 grant to help improve sustainable livestock production in Ethiopia and Burkina Faso, where dairy cattle produce 5 to 10 liters of milk per day compared to the 45 liters that cows in California can produce. He is working with researchers and funding from the University of Florida with support from the Bill and Melinda Gates Foundation.
âBy improving the quality and quantity of dairy production in developing countries, we help families rise from poverty and malnutrition, and also reduce the carbon footprint of cattle worldwide,â Kebreab said.
If seaweed proves to be a climate-smart supplement, producing it could be environmentally friendly, too. As Kebreab notes, âGrowing seaweed doesnât require land, fresh water or fertilizer.â
But there is still a lot to learn before farmers should consider feeding cattle seaweed.
âWe have much more research to do to determine if seaweed supplements could provide a viable, long-term solution,â Kebreab said. âBut we are very encouraged by these early results.â
Media Resources
Kat Kerlin, °”TV News and Media Relations, 530-750-9195, kekerlin@ucdavis.edu
Diane Nelson, °”TV College of Agricultural and Environmental Sciences, 530-752-1969, denelson@ucdavis.edu