Finally
-- A Test for Tenderness
Delivering
beef consumers a guaranteed tender product took a light-years leap
toward reality recently with the introduction of GeneSTAR Tenderness(R),
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 % 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 lb. or
greater), compared to 21% of the carcasses that were devoid of the
tender-friendly gene. In between, 13% 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 (Figure 1). On average, 80% of the British breeds in the study
contained two copies of the tender gene, compared to approximately
30% for the Brahman cattle evaluated; and 55-60% 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(R) Tenderness, and GeneSTAR(R) Marbling, Genetic
Solutions also offers SireTRACETM, DNA-based cattle parentage identification
and SureTRAK(R), 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