Research shows no need to sacrifice growth for intramuscular fat in lambs

Brothers Angus and Alistair Kelly of Marocara Dorsets, Wongarbon, include IMF values in their sale catalogue, although they find only a small number of their clients are actively seeking the trait.

Angus said their focus had always been on growth and muscle.

"Now they've created these couple of indexes that contain the IMF and the shear force - which is an industry-driven index - we've had to take notice of that and we've selected for those traits as well," he said.

"It's really hard to try and identify those genetics - the gene pool is getting pretty small to be able to try and identify those animals within the one breed."

Gundagai Meat Processors began paying a premium for IMF a couple of years ago but generally the trait is not rewarded by other processors.

"Commercial people aren't going to pay for it in a catalogue until they can see a market - that's the biggest challenge we've got," Alistair said.

"For that education to flow through as dollars per kilo, is that still five years away? We don't know."

Marocara has clients based around the state. The brothers found their eastern clients would pay for figures and eating quality traits, whereas western clients tended to chase numbers and growth.

Angus said achieving high IMF initially had an impact on growth but those animals had since been weeded out.

"I think there's plenty of sheep now that's been identified with high growth and also high IMF. They'll come through in the next few years," he said.

The eating quality research would benefit the whole industry and drive further improvements, he said.

"You're seeing that with other studs that aren't involved with Sheep Genetics, they're getting all the gains from all the information," he said.

"Ultimately you want a high-growth animal, a high meat animal with a high IMF and low shear force.

"You want all these traits, and also fertile, and all these other things.

"But you've got to be careful to balance it out. If you chase one, you're going to probably give away something else."

Some of the research into eating quality was discussed at a recent Dubbo field day hosted by the Tooraweenah Prime Lamb Marketing Co-operative.

Peta Bradley, from Meat and Livestock Australia, pointed to long-term data that demonstrated a decline in eating quality traits for several years, before that trend plateaued and reversed in 2016 when standard breeding values for IMF and shear force were introduced.

"For a long time, because of the price signals we had - breed them big, and breed them lean - we had this declining trend in intramuscular fat," she said.

"Our ram breeder flocks, despite there being absolutely no market signals at the time, began to use those breeding values and turn that trend around."

"They had the foresight that 'this is where the industry is going to go, we need to start to breed sheep that are going to help meet market specs for the future'."

Ms Bradley said about 50 per cent of an animal's IMF score came from its genetics.

She encouraged commercial producers to consider using breeding values to select for eating quality even if those traits were not driving profit for their operation at the moment.

"The rams you're going to be be buying this year - chances are they're still going to be in your sire team in four year's time and having progeny in five year's time," she said.

"These rams are going to be around for a while, and if you keep their daughters its going to be even more important - they'll be around potentially 10 years down the track.

"Where is our market going to be in that time? Eating quality may well be very important."

There was as much variation with IMF across breeds as there was between breeds, she said.

Lachlan Jeffers, Meat Standards Australia business development officer for MLA, said a cuts-based model for sheepmeat had been hindered by a lack of approved devices to measure eating quality.

"We need more of those technologies approved by AusMeat - competition is good," he said.

"If we get more of them they get tighter in their readings and more accurate readings and more consistent readings."

Once reliability improved and prices came down, it was more likely processors would use the technology, he said.

"Our major issue currently is computer systems talking to each all and all syncing up," he said.