A test for tenderness

Delivering consumers a guaranteed tender beef product took a leap toward reality with the introduction of GeneSTAR Tenderness®, a DNA-based test that identifies variants of the calpastatin gene, a naturally occurring enzyme that inhibits normal meat tenderization during post-harvest aging.

In fact, research conducted ahead of launching the test the industry's first viable pre-harvest tenderness selection tool indicates that testing and selecting for differences in the calpastatin gene reduces the number of tough eating steaks by at least half.

Such improvement would provide the industry exponential benefit considering the fact that consumer taste panels continue to identify beef tenderness as the primary component of eating satisfaction.

"A major scientific effort has now delivered beef producers a simple live animal test that will help them meet customer expectations," explains Jay Hetzel, Chief Scientific Officer for Australia-based Genetic Solutions, which is marketing the test. "GeneSTAR Tenderness should have long-term benefits for beef quality around the world."

What It Is
Until now, measuring tenderness practically has been a vexing challenge because so many pre-harvest and post-harvest variables affect this important trait.

Realistically, the only reliable post harvest method so far requires the use of Warner Bratzler Shear Force (WBSF) instruments that measure the amount of force it takes to cut through a piece of meat. That means the only chance to select for tenderness genetically has been to collect WBSF data from a sire's progeny extremely difficult and costly. GeneSTAR Tenderness changes that.

Based upon gene marker research conducted by Australia's Cattle and Beef Quality Cooperative Research Center, CSIRO Livestock Industries and Meat and Livestock Australia, the GeneSTAR Tenderness test identifies two variations of the calpastatin gene one associated with increased tenderness and the other associated with increased toughness.

In independent studies carried out by the research consortium and encompassing 5,016 carcasses, only 8 percent of the carcasses from cattle with two copies of the tender-friendly calpastatin yielded Warner Bratzler Shear Force (WBSF) values regarded as tough (12.5 pounds or greater), compared to 21 percent of the carcasses that were devoid of the tender-friendly gene. In between, 13 percent of the carcasses with a single copy of the tender-friendly gene were measured as tough. All told, carcasses with two copies of the tender gene were almost a full pound of WBSF more tender than those with two copies of the tough gene.

What's more, the study underscores the fact that there are differences in frequency of the tender gene between breeds as well as within a breed. On average, 80 percent of the British breeds in the study contained two copies of the tender gene, compared to approximately 30 percent for the Brahman cattle evaluated; and 55-60 percent for the Bos Indicus composites that were genotyped. Researchers emphasize, however, all breeds in the study included animals that carried the tough gene.

Hetzel points out the gene involved in the GeneSTAR Tenderness test is only one gene impacting tenderness, but he adds, "The effects of selection using this test are permanent and cumulative within the herd."

In addition, because the relationship between marbling and tenderness is known to be positive though weak, any tenderness gains should not be at the expense of increased marbling. Incidentally, Genetic Solutions introduced the world's first commercial DNA test for a beef production trait two years ago with the GeneSTAR Marbling evaluation. This test, which identifies the presence of the thyroglobulin gene indicating increased levels of marbling is being used by cattle producers around the world today.

How It's Used
While GeneSTAR Tenderness can be used to evaluate tenderness at the carcass stage, Genetic Solutions expects most initial use to come from seedstock producers who use the test to construct genetic tenderness profiles of their herds and to use in selecting sires. As well, commercial producers may begin asking their seedstock suppliers for a tenderness evaluation of prospective purchases.

"From a genetic point of view, the critical control point for herd tenderness is at each mating," explains Hetzel. "By selectively breeding to animal with two copies of the tender gene, breeders could ultimately eliminate animals from their herds that carry the tough form of the gene."

For producers, conducting the test is as simple as submitting tail hair follicles or thawed semen to Genetic Solutions" laboratories.

 "The commercial release of this test heralds a new era for beef consistency and consumer satisfaction capable of sustaining and growing demand."

Genetic Solutions has offices in Australia and the United States. In addition to GeneSTAR® Tenderness, and GeneSTAR® Marbling, Genetic Solutions also offers SireTRACETM, DNA-based cattle parentage identification and SureTRAK®, a DNA-based traceability system currently being used by beef processors in Australia and the United States.  Contact can be made through the US Colorado office at 720-890-2832 or by visiting www.geneticsolutions.com.au

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