Kangaroos produce relatively little methane, but study suggests transplanting gut micro-organisms into sheep or cattle would not help reduce emissions
Australian Associated Press
New analysis of kangaroo farts suggests their low methane levels could have implications for farmers in the fight against climate change.
It has long been known that kangaroos – unlike sheep and cattle – produce little of the potent greenhouse gas methane.
For some time, researchers intent on breeding less windy flocks and herds hypothesised kangaroos might have a unique mix of micro-organisms in their stomachs that produce less of the gas.
The hope was by transplanting these micro-organisms, cattle and sheep might produce less methane.
But new findings suggest otherwise, and should help refocus sheep and cattle research on alternatives that might yield results.
The experiment saw red and western grey kangaroos kept in comfy, sealed chambers, allowing researchers to analyse the mix of gases going in and coming out.
“We think that the methane is low because of the way food moves through the kangaroo stomach, and not because of a unique gut fauna,” study author Dr Adam Munn said.
The battle for less windy livestock is a serious issue when it comes to climate change.
In the year to March 2015, agriculture accounted for 15% of Australia’s greenhouse gas emissions. The agricultural sector is the nation’s dominant source for methane.
Munn says more research needs to be done to work out the contribution various species make to greenhouse gas emissions.
He says information will be valuable to Australian farmers in the future, under any carbon pricing or credit system.
“We need to understand where the ruminants sit compared to other wildlife that aren’t heavily domesticated for production systems,” he says.
“If we know that there may be, for example, some benefit for land managers to having a lower density of [methane] intensive animals, and having mixed species grazing, instead of single species grazing.”
The research is the work of Munn, from the University of Wollongong, Professor Marcus Clauss from the University of Zurich, and PhD student and vet Catharina Vendl.
It was carried out at UNSW Fowlers Gap Arid Zone research station in far western NSW, and the findings have been published in the Journal of Experimental Biology.