Vermont dairy farmers Tim Maikshilo and Kristen Dellert, mindful of shrinking their carbon footprint, have changed their cows’ diet to reduce the amount of gas the animals burp — dairy cows’ contribution to global warming.

Coventry Valley Farm is one of 15 Vermont farms working with Stonyfield Farm Inc., whose yogurt is made with their organic milk, to reduce the cows’ intestinal methane by feeding them flaxseed, alfalfa, and grasses high in Omega 3 fatty acids. The gas cows belch is the dairy industry’s biggest greenhouse gas contributor, research shows, most of it emitted from the front and not the back end of the cow.