Bull buyers should be selecting sires with above breed average marbling and adequate fat to breed higher eating quality carcases, according to University of Adelaide School of Animal and Veterinary Sciences’ animal breeding and genetics professor Wayne Pitchford.
But he encouraged them to start with a balanced breeding index, reflecting their target market.
“A lot (of producers) make sure they get the best looking animal possible and then look at a few key traits and then hopefully they end up with a good index – that is completely the wrong way around,” he said.
Speaking at Teys Australia’s Naracoorte producer day last week, Prof Pitchford said producers also needed to look at the individual Breedplan estimated breeding value for key traits.
“Extreme numbers (within EBVs) should be treated like structural faults,” he said.
“Given the emphasis on 36 degres south (Teys brand) and if you want to be part of that exciting process – if you are choosing below average marbling bulls that is not going to be happening,” he said.
He said structural soundness should be the final consideration but those not selecting bulls using Breedplan as a tool were missing out.
“Some people think that they can assess the value of an animal just by looking at it – but quite frankly they are wrong,” he said.
“They cannot tell the marbling of the progeny of a bull just by looking at it, they cannot tell the reproductive performance of a bull’s daughters by looking at a bull.”
Prof Pitchford gave an example of the economic value of buying bulls in the top 10pc of 2016-drop bulls from SA herds on the Angus Breeding Index compared to breed average.
Those in the top 10pc were worth $27 more for every cow joined, with 7kg more carcase weight, 0.6 square centimetres more eye muscle, 0.3pc higher intramuscular fat and 0.4pc better calving ease.
The only trait in the index heading in the wrong direction was mature cow weight at +13kg but Prof Pitchford said breeders should accept their cows will become larger framed.
“You can be really, really concerned about that and focus on that and make sure your cows are genetically no bigger but actually you will be limiting progress in traits that affect profit,” he said.
“We are lucky we are not just selecting on lean meat yield.
“A focus on higher carcase weight, high muscle and high intramuscular fat is going to prevent us going too extreme in our cows.”
Prof Pitchford said the accuracy of EBVs would grow with the use of genomics, especially coupled with emerging objective carcase measurements.
He is working with several commercial breeding programs and breed societies on genotyping carcases to feed into genetic evaluation systems.
Many other contributors to a high MSA index were management-related and he reminded producers to ensure their cattle were on good nutrition and not put under stress pre-slaughter.
“Don’t rely on genetics to solve poor management,” he said.
