Progeny of Trangie bulls identified as being high or low methane emitters are to be tested for feed efficiency and methane production, to demonstrate whether direct breeding for low methane production might be possible.

"Funny as it may sound, between 28 and 60 per cent of people in western societies produce methane, while the others do not, and methane from humans has been shown to be moderately heritable," NSW Department of Primary Industries (DPI) principal research scientist, Robert Herd, said.

So too is feed efficiency in cattle moderately heritable, Dr Herd says, and the accompanying reduction in feed intake has been shown to reduce methane emission.

NSW DPI scientists have already shown that breeding for improved feed efficiency is possible.

"Economic modelling has already shown that just modest adoption of breeding for improved efficiency is an effective strategy for reducing methane emissions by cattle.

"Something like 95pc of methane from cattle is burped up from their bellies rather than from behind but either way it’s odourless.

"The energy in feed consumed by cattle over a year and burped out as methane represents the equivalent of one month of feed energy simply lost to the earth’s atmosphere."

Dr Herd and Dr Roger Hegarty and their team have been working at the Beef Industry Centre in Armidale to find easier methods to measure methane production, to investigate genetic variation, and to find a lot of low methane-emitting bulls.

"We measure methane from research cattle using the bovine backpacks, but some new methods will be required, before large numbers of breeding bulls can be monitored."

In conjunction with the CRC for Beef Genetic Technologies, the NSW DPI scientists are working to deliver DNA markers to help find feed efficient bulls for cattle breeding and develop strategies to manage the methane-producing microbes in the rumen.

"Together these advances promise to greatly reduce methane emission without compromising livestock production," Dr Herd said.

"Production systems in which cows have a calf every year, with well-managed pastures to ensure progeny are turned off at a young age, will have lower emissions per tonne of beef produced."

Meeting the targets

There is a compelling case for beef producers and their representatives to be informed about, and to contribute to, national policy on meeting greenhouse-gas emission targets, says NSW DPI’s Dr Robert Herd.

Livestock, mainly beef cattle and sheep on pasture, with smaller contributions from dairy and feedlot cattle, contribute 70 per cent of agricultural greenhouse-gas emissions, and agriculture contributes around 16pc of Australia’s total emissions.

Contact Robert Herd, Armidale, (02) 6770 1808, robert.herd@dpi.nsw.gov.au