CORVALLIS, ORE. — Oregon State University received a $1 million grant from the US Department of Agriculture National Institute of Food and Agriculture (NIFA) to research the impact of adding seaweed to cattle’s diets to reduce greenhouse gas (GHG) emissions.

The five-year study will focus on one seaweed species — Pacific dulse, which is grown commercially on the Oregon Coast. Researchers will analyze the effects of including this seaweed in the diets of cattle that typically graze sagebrush steppe landscapes — those common in the western United States.

“Most of the research on seaweed feed supplementation for cattle has taken place in feedlots,” said Rory O’Connor, a rangeland ecologist with the USDA’s Agricultural Research Service in Burns, Ore., and co-director of the project. “Our work is novel because we are focused on cattle that graze in the sagebrush-steppe ecosystem.”

The study will be a continuation of recent research that has found that seaweed diets can reduce methane emissions from cattle, most of which originate from enteric fermentation.

“At a time of heightened public concern about greenhouse gas emissions, this project has the potential to help ranchers more sustainably and efficiently produce beef while also providing an economic benefit to seaweed producers,” said Juliana Ranches, project director and an assistant professor at Oregon State’s Eastern Oregon Agricultural Research Center.

According to the US Environmental Protection Agency (EPA), the agricultural sector is responsible for 9.4% of GHG emissions in the United States, with cattle accounting for more than a quarter of that percentage.

For the project, around 20 cows will graze each year in a 100-acre pasture at the Northern Great Basin Experimental Range in Riley, Ore. The cattle will wear GPS collars and be confined to the area through a virtual fence.

Researchers will supplement the cattle feed with Pacific dulse, supplied by the company Oregon Seaweed. The cattle will receive different amounts of dried dulse to access the supplementation level that most suppresses enteric methane.

“We will also be looking at the way the seaweed is grown and how that impacts the compounds of interest that contribute to methane reduction,” said James Fox, an algal physiologist in the Oregon State Department of Microbiology and co-investigator of the project.

Fox will also work with colleagues at OSU-Cascades to study the impact seaweed supplementation has on bacteria in the cattle stomachs and how the bacteria may contribute to methane reduction.

Additionally, the researchers will use an atmospheric measurement tool called an Eddy Covariance Flux Tower to measure changes in carbon dioxide and methane levels in the pasture.