Sheep to wear greenhouse masks | NEWS.com.au

AUSTRALIAN researchers will not fit plastic trousers to sheep as a means of measuring rear-end greenhouse gas emissions.

But they will have to fit masks to thousands of sheep to see exactly what they are belching.

Stung by climate adviser Ross Garnaut's recent claim that sheep help cause climate change and people should eat kangaroo instead, the industry is responding with a large field trial.

Sheep Cooperative Research Centre chief executive James Rowe said staff would corral sheep at research stations and hold the masks in place for about a minute each, to collect their breath.

"It's just a mask over the nostril-mouth area, as the animal breathes out. That air is then captured into a bladder, not too different from a football bladder.

"The animal is not in any distress ... they don't really object to it."

Ruminant animals like sheep are in the climate sin-bin because they emit the potent greenhouse gas methane, both from the mouth and the rear.

Researchers, in the past, have fitted them with plastic trousers to measure rear-end emissions.

Professor Rowe said that would not be part of the trial because only about 2 per cent of sheep methane emissions came from their rear.

"Putting plastic trousers on sheep is much more difficult than holding a mask there for a minute or so," he said.