Cattle and other ruminant animals are thought to be responsible for around one-fifth of the world’s greenhouse methane gas production but the precise amount has proved difficult to quantify.
With the new discovery, scientists could now be able to measure the potent greenhouse methane gas that is produced by cattle and other ruminants.
Researchers from the University of Bristol and the Teagasc Animal and Grassland Research Centre in Ireland, have found a link between methane production and levels of a compound called archaeol in the feces 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.
Archaeol is thought to come from organisms called archaea, which are symbiotic or ‘friendly’ microbes that live in the foregut of ruminant animals. These microbes produce methane as a by-product of their metabolism and this is then released by the animal as burping and flatulence.
Principal investigator, Dr Ian Bull of Bristol’s School of Chemistry said: “We initially detected archaeol in the feces 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 feces of cows with different diets.
“Two groups of cows were fed on different diets and then their methane production and fecal archaeol concentration were measured. The animals that were allowed to graze on as much silage as they wanted emitted significantly more methane and produced feces 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 is published in the journal Animal Feed Science and Technology.