Backpacks measure cows' methane
Backpacks have been fitted to cows in Shropshire to help monitor how much methane they emit.
Tubes slowly suck in an air sample from the loop over the cows' nose and mouth into the backpacks which are changed every 24 hours.
Researchers at Harper Adams University College in Newport want to try to reduce the amount they produce and are changing their diets.
Climate experts have said methane accelerates global warming.