Hilda the calf looks like any other cow, but she has been genetically modified to pass less gas. The methane gas cows produce isn't just smelly...it has a real impact on the environment. In fact, cattle produce 5% of the world's greenhouse gasses. The Cool Cows project in the UK involves breeding cows to be less flatulent. "Genetic improvement in methane efficiency is going to be key to continuing to provide nutritious food to the public, while controlling the impact of methane emissions on the environment," Rob Simmons from the Paragon Veterinary Group said. (dailymail.co.uk)