Save the planet – stop cows burping. Unlikely as that sounds, it's a serious scientific mission. Cattle around the world produce huge amounts of methane, a powerful gas, which accounts for about a fifth of the greenhouse effect. The methane cows belch out every day floats into the stratosphere to join carbon dioxide and other gases holding in the Sun's reflected heat and causing the Earth's temperature to soar, with potentially disastrous effects. But researchers at the Rowett Research Institute in Aberdeen say they are close to producing a bovine belch-inhibitor. It is a combination of sugars and a novel...