Scientists in Scotland are investigating ways to cut the amount of methane emitted by cattle, paving the way for the breeding of low-emission livestock. Matthew Stock reports.
Cattle produce a lot of methane - a potent greenhouse gas and major contributor to global warming. The first of their four stomachs - called the rumen - holds gut microbes that dicate how much methane they produce. SOUNDBITE (English) RICHARD DEWHURST, PROFESSOR OF RUMINANT NUTRITION, SCOTLAND'S RURAL COLLEGE (SRUC), SAYING: "They have this sort of pre-fermentation vessel, it's what allows them to use low-quality forages - to convert grass and silage and straw into milk and meat. Things that we can't eat into things that we can eat. Now, the rumen fermentation does lots of good things, but one of the bad things that it does is produce methane.... And contrary to popular belief it comes out of the front end; 95 percent of the methane emissions from ruminance are from the front end of the animal, very little from the back-end." That means a lot of belching. Globally, livestock production emits half of the world's methane emissions. Researchers from Scotland say they've found the link between an animal's genetic background, diet, and the make-up of its gut microbes. In these respiration chambers, animals are monitored over three days and their various gaseous emissions analysed. SOUNDBITE (English) RAINER ROEHE PROFESSOR OF ANIMAL GENETICS AND MICROBIOME, SCOTLAND'S RURAL COLLEGE (SRUC), SAYING: "We're always looking at the impact of the feed on methane emissions and, in the second case, we are looking at the genetics on methane emissions....And if we are predicting those traits quite accurately based on the microbial community then we can use this information for breeding purposes." The demand for a Western-style diet rich in milk and beef - especially in Asia - is fuelling a surge in livestock-led greenhouse gases. Work is on-going in Scotland, developing a method to help farmers globally understand their livestock's gut biology, and breed more eco friendly animals.