Reuters: Canadian scientists are breeding a special type of cow designed to burp less, a breakthrough that could reduce a big source of greenhouse gases responsible for global warming. Cows are responsible for nearly three-quarters of total methane emissions, according to Environment Canada. Most of the gas comes from bovine burps, which are 20 times more potent than carbon dioxide as a greenhouse gas. Stephen Moore, a professor at the University of Alberta in Edmonton, is examining the …