AUSTRALIAN scientists are hoping to breed burp-less sheep in a bid to reduce greenhouse gas emissions.

The agriculture sector is the nation's second biggest source of greenhouse gas emissions behind the energy sector, producing about 16 per cent of Australia's total emissions, the Courier-Mail reports.

Two-thirds of that figure is produced by livestock, and 66 per cent of those emissions are released as methane from the guts of grazing livestock such as sheep and cattle.

The Sheep Co-operative Research Centre is conducting a world-first study into about 700 sheep with 20 different genetic lines – each is fed, then shepherded into a booth where scientists measure their burp outputs.

One study leader, Dr Roger Hegarty, said sheep burped large amounts of methane and there was environmental pressure to see whether that could be minimised.

"We're looking into how to reduce emissions from sheep – all over Australia teams are testing different approaches: changing the microbes in the gut, changing their diet, or changing the genetics of the animal," he said.

"Our sheep studies are (primarily) aiming to find out if there is genetic control over methane production and, if so, is that a good thing to pursue?"

Dr Hegarty said researchers were wary not to produce other problems in their bid to reduce the animal's carbon footprint.

"Methane is the exhaust from livestock, and – just as you can't put your hand over the exhaust pipe of a car and expect it to keep running – we're treading carefully to reduce emissions without causing other problems.

"There really is a global effort on this – it will take a lot of hard yakka and time."

Other study leader, Dr John Goopy of the NSW Department of Industry and Innovation, said if a 10 per cent reduction could be achieved per animal it would be a good thing.

"Once we work out how to reduce methane emissions, and if our strategies prove to be valid, we will keep gaining advantage and over time there will be larger decreases in methane emissions," he said.

Dr Hegarty said scientists were also looking to do a similar thing with beef cattle.

Originally published as Boffins aim to shear sheep gas emissions