Feeding seaweed supplement to cattle halved methane emissions in Australian feedlot, study finds

The trial at Kerwee Feedlot involved feeding a commercial Asparagopsis supplement in the form of an infused canola oil over 200 days Photograph: The Guardian

It takes a tasty treat to lure a cow’s head into the narrow channel of a solar-powered contraption mounted to the back of a trailer.

Once inside, and munching away at the sweet pellet, sensors measure the potency of the animal’s methane-laden burps. By the water trough, another device calculates the cow’s weight, and over the fence tubs of feed on scales record how much it eats.