According to the Food and Agriculture Organization of the United Nations, livestock accounts for approximately 12 percent of all greenhouse gas emissions, most of which is produced when cattle burp. Grazing bovines belch a greater amount of methane than feedlot or dairy cows because they consume more fiber from grass.

In a study published in Proceedings of the National Academy of Sciences, researchers at the University of California, Davis, found that feeding grazing cattle a seaweed supplement reduced methane emissions by almost 38 percent without affecting the animals’ health or weight. The 10-week experiment on a ranch in Montana involved 24 steers divided into two groups—one was given a seaweed supplement in pellet form, and the other was not. The findings offer a way to make cattle grazing more environmentally friendly.