by Megan Winslow, University of Florida

Cows produce methane, a greenhouse gas, as they digest grass and hay. In the quest to identify an alternative livestock feed to reduce the amount of methane cows produce, seaweed has emerged as a promising contender.

“There has been a steady rise in concerns among consumers over environmental sustainability. Using seaweed to reduce potent greenhouse gas emissions can be an avenue toward meeting consumer preferences for the foods they purchase,” says John Lai, assistant professor of agribusiness in the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) food and resource economics department.

But are consumers willing to pay extra for low-emission milk and low-emission beef?

Building on existing UF/IFAS research into seaweed’s environmental benefits, Lai and his colleagues are conducting research to test its economic viability. A recently published data illustration provides an early peek at their ongoing study of Asparagopsis armata, a species of red seaweed. The illustration, published in the Agricultural & Applied Economics Association’s Choices magazine, is a product of collaboration between Lai; his colleague Andrew Ropicki; and students Emerson Searl, an undergraduate, and Meri Hambaryan, a doctoral candidate. It describes the associated pros and cons of cultivating seaweed to feed dairy cows and cattle.

Red seaweed reduces methane emissions because it contains high levels of bromoform, a compound that inhibits enzymes involved in the creation of methane gas, according to the illustration. Rich in protein, carbohydrates and dietary fibers, seaweed meets the dietary needs of livestock without negatively affecting the taste, smell or texture of beef or milk.

Additionally, the environmental benefits associated with seaweed cultivation extend beyond methane-emission reduction, says Ropicki, an assistant professor specializing in marine resource economics.

“Relative to other methane-reducing cattle feeds, seaweed is notable for its ability to absorb nitrogen and phosphorus, which feed harmful algal blooms.” — Andrew Ropicki

“Relative to other methane-reducing cattle feeds, seaweed is notable for its ability to absorb nitrogen and phosphorus, which feed harmful algal blooms,” Ropicki said. “By capturing carbon dioxide from oceans, seaweed can counteract ocean acidification and improve water quality.”

Challenges

There are some downsides, however.

Red seaweed can contain heavy metals, iodine and minerals that may pose health risks to animals, so continuous monitoring is required during cultivation to prevent toxicity.

Other obstacles include the logistical hurdles of hauling large quantities of seaweed, energy-demanding processing requirements and high prices associated with potential seaweed shortages.

“There are challenges, but we believe they can be overcome, and there is a potential market for seaweed cow feed.” — Andrew Ropicki

“There are challenges, but we believe they can be overcome, and there is a potential market for seaweed cow feed,” Ropicki says.