Feeding cattle seaweed could reduce methane emissions

A research team led by the Bigelow Laboratory for Ocean Sciences has just received a $10 million grant from the U.S. Department of Agriculture to continue their study of how methane emissions by cattle could be reduced. During the course of the investigations, which was initiated in 2019, the scientists found that replacing cattle’s usual grain diet with seaweed could decrease by 20 percent the amount of methane released in the atmosphere.

Methane is one of the most potent greenhouse gases, trapping 30 times more heat than carbon dioxide and thus contributing significantly to global warming. Cows are notorious for releasing large amounts of methane into the atmosphere (approximately 25 percent of the total methane emissions) by passing gas or burping. 

“Despite the best efforts to try to find ways to reduce that carbon ‘hoofprint,’ there’s lots more that can be improved in terms of changing cow’s diets. We think that seaweed can be part of that solution,” said project lead Nichole Price, a senior research scientist and director of the Center for Seafood Solutions at Bigelow Laboratory.

The Bigelow Laboratory has spent the last two years developing tools to evaluate how changing the cattle’s diet to seaweed could potentially help reducing methane emissions. The scientists tested how a variety of nutrient-rich Maine seaweeds could help not only reduce cows’ methane emissions, but also improve their health and even the quality of the soil where they pasture.

“This is some of the most exciting research I’ve been a part of,” Price said. “It has the potential to curb global methane emissions, and our approach can also directly support the region’s dairy and seaweed farmers.”

According to Price, creating new seaweed products could bolster Maine’s seaweed aquaculture industry, help recycling crucial nutrients, remediate a variety of ocean conditions, and empower the dairy industry to improve the health of cattle and of the planet in general.

The scientists screened several types of seaweeds for important compounds that could make them good candidates for a feed additive.

“Different types of seaweeds have different impacts on the complex microbial environment inside a cow’s rumen,” explained Sabrina Greenwood, an associate professor of Animal Nutrition at the University of Vermont. 

“The approach taken by this project provides an incredible opportunity to really push ahead with identification and refinement of natural nutritional supplements that could be great for both the cow and the environment.”

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By Andrei Ionescu, Earth.com Staff Writer