Cattle producers not sold on genetic test for tenderness

VANCOUVER — Aging can improve a tough steak, but a genetic test that could determine which cattle produce tender meat in advance might save the beef industry a considerable sum in storage costs.

“As we age the beef for a different number of days, we get less and less beef in this tough category,” said Steve Miller of AgResearch in Invermay, New Zealand, and formerly an animal geneticist at the University of Guelph.

A 21 day aging period nearly eliminates the problem in all carcasses, but it can be expensive.

Aging from seven to 21 days results in variable quality for consumers.

“Steaks can be variable. Sometimes it’s not that great,” he told the World Congress on Genetics Applied to Livestock Production, which was held in Vancouver Aug. 17-22.

The Canadian beef quality audit in 2011 showed improvements had been made since the last assessment 10 years ago. Tenderness improved but there were tradeoffs. Cattle are fatter and red meat yield is less.

“I am not convinced our problem has gone totally away,” Miller said.

Commercial genomic predictions for tenderness have been available for some time, and breed associations such as Simmental and Angus provide that information for breeders. However, participation has been slow among producers and there is no reliable prediction tool for crossbreds, which make up most of the Canadian herd.

There is money to be made in offering tender beef.

VG Farms of Simcoe, Ont., has just launched a guaranteed tender program, which is paying off for the family owned operation. A Warner Bratzler shear force test is run on every carcass, but Miller said large packers would not likely be willing to go to such lengths because of cost.

The test determines how much force is required to cut through a piece of cooked meat.

A DNA test may be able to separate the tender from the chewy.

Genomics is the extraction and analysis of DNA to identify important genetic markers.

The Canadian genome project is looking at a number of economically valuable traits, including tenderness studies.

The U of G conducted a lengthy tenderness evaluation project on its research herd consisting of Simmental-Angus cows. It also added commercial cattle from unknown sources to the mix to compare results.

The university selected groups of 60 crossbred bulls from 2003-13, collected their semen and slaughtered them. The beef was tested for toughness, and semen from those that produced the most tender cuts was used to produce the next generation.

The correlation between the bulls’ shear force results and information based on progeny data from the university herd was moderate. Commercial animals of similar breeding to the research cattle were bought from elsewhere for comparison. Their results were less predictable.

Producers are less likely to use current tests if the predictability is low, but Miller said some value chains may consider them because they would know more about the animals involved.

However, he was not convinced most companies would be willing to DNA test all animals just to eliminate a few tough ones. The tests cost about $25 each.

Research also found that cattle carrying the double muscling gene were more tender, which could change how people think about continental cattle that carry the heavier development. Known as the myostatin gene, which is connected to muscle development, those animals appeared to produce more tender sirloins.

“If we could sell those sirloins at the same price as strip loins, that would add $50 to a carcass,” Miller said.

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