Great gas as Grange boffins uncover secrets of methane

For years, methane gas produced by grazing cows has been blamed by many, including former Beatle, Paul McCartney, for causing global warming. The knighted singer even wanted people to stop eating meat for that very reason. However, researchers at Teagasc Grange in Dunsany, along with scientists in the University of Bristol, could have a revolutionary new way of measuring how much of the potent greenhouse gas, methane, is produced by cows and other ruminants, thanks to a surprising discovery in their poo. Researchers from the university and the Teagasc Animal and Grassland Research Centre in Dunsany have found a link between methane production and levels of a compound called archaeol in the faeces of several fore-gut fermenting animals, including cows, sheep and deer. The compound could potentially be developed as a biomarker to estimate the methane production from domestic and wild animals, allowing scientists to more accurately assess the contribution that ruminants make to global greenhouse gas emissions. Principal investigator, Dr Ian Bull of Bristol's School of Chemistry, said: "We initially detected archaeol in the faeces of several foregut fermenters, including camels, cows, giraffes, sheep and llamas. We then expanded the study to evaluate the quantities of this compound in the faeces of cows with different diets. "Two groups of cows were fed on different diets and then their methane production and faecal archaeol concentration were measured. The animals that were allowed to graze on as much silage as they wanted emitted significantly more methane and produced faeces with higher concentrations of archaeol than those given a fixed amount of silage, supplemented by concentrate feed. This confirms that manipulating the diet of domestic livestock could also be an important way of controlling methane gas emissions." The research was funded by the Leverhulme Trust. The research is published in the journal, Animal Feed Science and Technology.