In this June 8, 2018 image taken from video, cows are milked at a dairy farm at the University of California, Davis, in Davis, Calif., where researchers are feeding seaweed to dairy cows in a bid to make cattle more climate-friendly. UC Davis is studying whether adding small amounts of seaweed to cattle feed can help reduce their emissions of methane, a potent greenhouse gas that's released when cattle burp, pass gas or make manure.