Case study - Science proves it's possible to breed green livestock

​Case study – Department of Agriculture, Fisheries and Forestry, Australia’s Farming Future: Climate Change Research Program (CCRP)

Science proves it’s possible to breed green livestock

Livestock producers are used to selecting the bulls or rams they wish to buy with particular traits.

Growth rate, calving or lambing ease, fertility rates, are all high on the list when looking for that perfect sire.

But one day it just might be possible to select sheep or cattle that also have a smaller environmental footprint with Australian scientists proving that it is possible to breed livestock that produce less methane.

The world-class research conducted in Armidale, New South Wales, was just one part of 39 research projects coordinated by Meat & Livestock Australia through the Reducing Emissions from Livestock Research Program (RELRP).

The RELRP was funded through the Australian Government’s $46.2 million Climate Change Research Program (CCRP). The RELRP national program co-ordinator, Dr Julian Hill, said the RELRP, has delivered new knowledge in five main areas: genetics and animal selection, nutrition, rumen microbiology, farming systems and waste management.

“The work provided to future selection and breeding options for low methane sheep and beef cattle,” he said.

“Scientists have also developed a range of nutritional and management strategies that can be adopted by the industry to reduce methane and nitrous oxide emissions; and identified key biochemical and metabolic pathways that can be manipulated in the future to reduce the overall production of methane in the rumen.”

Dr Robert Herd, Principal Research Scientist from the NSW Department of Primary Industries, Beef Industry Centre in Armidale said that given that methane is 25 times more potent than carbon dioxide in global warming potential, the aim of the project he was involved in was simple.

“Basically we wanted to determine whether there was a natural variation in the amount of methane animals produce,” he said.

“And if the answer was yes, was there a genetic basis for that, and if so, whether it was possible to breed animals that naturally produce less methane,” said Dr Herd.

The ability to individually measure methane in large numbers of cattle has been an important advance for researchers in the search for low methane emitting animals.

“We brought all the cattle from our research herds at Trangie in central west NSW and Glen Innes in northern NSW to our facilities at the University of New England (UNE) where we have large purpose-built perspex chambers,” he said.

“The chambers allowed us to capture all the methane gas the animals produce.”

Dr Herd said methane production is largely related to how much feed an animal eats.

“If we just measured how much methane each animal produced each day and then bred those animals that produce less, we could end up choosing animals which just eat less,” he said.

“Those animals aren’t necessarily the ones producers want to breed from because they could be less productive.”

“So we measure methaned in terms of how many litres of methane they emit per unit of feed intake because we wanted an animal which eats well, was just as productive but produced less methane,” said Dr Herd.

Dr Herd said by the end of the project they had multiple measurements on more than 700 animals.

He maintained there was a three-fold variation between the high methane-emitting animals and low methane-emitting animals.

“Usually each animal produces about 25 to 30 litres of methane per kilogram of feed intake,” he said.

“But our research found some animals that produced less than 20 litres of methane per kilogram of feed intake while some animals produced well over 40.”

He said because all of the animals were from pedigree research herds, they could easily determine which sires produced progeny that produced less methane.

“There was at least a 25 per cent difference between our best and worst sires in terms of methane their progeny produced,” said Dr Herd.

Dr Herd said while research was conducted in Angus herds, he expected the results to apply to other cattle breeds as well.

“If we look at a trait like feed efficiency, which is related to methane, we see variation in all the breeds we’ve tested including Shorthorns, Herefords, Angus, Brahman as well as a range of composites,” he said.

“So it is quite likely that there will be a natural variation in the amount of methane produced as well.”

But it’s not only cattle producers which may benefit from this research. Dr Hutton Oddy, NSW DPI Principle Research Scientist at Armidale analysed and interpreted genetics data from methane reduction research in sheep flocks.

Dr Oddy said results indicated that the trait of reduced methane was low to moderately heritable in sheep.

“It was somewhere in the order of 0.2, which meant the heritability was in about the same order of magnitude as worm egg count in sheep, but certainly higher than reproductive rate,” he said.

“So selecting for reduced methane can be done, in theory, in practice it poses some challenges.”

Dr Oddy said that the biggest stumbling block in sheep research to reduce methane is the fact that there isn’t yet a cheap, easy and accurate way to measure methane production in sheep.

Both researchers indicated that the research needs to look for more than just methane emission reduction.

“It’s extremely important to know that if we breed animals that naturally produce less methane then there are no adverse associations with things like growth rate, body composition or fertility,” said Dr Herd.

“In animals we measured for methane emission we also measured growth rate, used ultrasound technology to scan body composition, subcutaneous fat, eye muscle area and marbling and we saw no adverse associations.”

That’s reassuring for producers like Sam White, who runs a mixed grazing operation of stud and commercial Angus cattle ‘Bald Blair’ east of Guyra in northern NSW.

“This research definitely has a place just like every other trait we currently measure for,” said Mr White.

“In terms of the benefit to industry, that will come about when it can be shown that there is a cost effective way of including it as part of a producers’ selection decision.”

Mr White said if the research produces an Estimated Breeding Value (EBV) for methane production over time then he believes it will become part of the big equation.

“If they can prove there are no antagonisms between other traits, for example fertility, growth or carcass traits then selecting low methane emitting cattle really is a win-win.”

Dr Herd said ultimately that was the aim. To see the trait of reduced methane incorporated into current breeding tools like EBV’s.

“EBV’s tell producers a little bit about the genetic merit of the bull they are looking at purchasing,” he said.

“So they look at a bull sale catalogue and they can easily tell how the bull is going to perform in the traits they want to improve.”

“Our objective is to one day have an EBV or a breeding value for methane related traits.”

Dr Herd said producers may also be interested in breeding cattle that produce less methane because the market may demand it.

“We’ve already seen supermarkets in Australia promoting beef that is free from hormone growth promotants. Who’s to say in the future, they won’t aim to get an edge over their competitors by promoting meat which comes from livestock that produce less methane?”

And it’s the future that New England Superfine wool producer Gerard Stephens, ‘Waranne’ is focusing on.

Leading figures in the Australian wool industry, the Stephens family runs a 25,000 self-replacing superfine merino flock and 1st-cross lamb operation on 7,200 hectares north-west of Armidale.

Mr Stephens said producers are slowly beginning to realize how big an issue methane production is becoming.

“Whether we like it or not, the world is getting warmer and we all have to do our bit to reduce the greenhouse gases which contribute to a changing climate,” he said.

“But we also have to feed and clothe the billions of people that rely on us every day.”

He said even if no-one can predict exactly what the future holds, it’s important to undertake research like this.

“If for every 1000 projects we see just one initiative that can improve things for the future generations of farmers, then it’s worth investigating in my opinion,” said Mr Stephens.