GeneSTAR Tenderness and Quality Grade Tests
GeneSTAR® Tenderness identifies animals that are more likely to produce tender cuts of beef. GeneSTAR Tenderness is a DNA marker test for two important genes, Calpastatin & Calpain, involved in the post-mortem tenderization process of beef. Animals carrying the favorable forms of the genes have been found to significantly reduce the proportion of "tough" eating experiences. Click here to learn more about the GeneSTAR® Tenderness tests.
GeneSTAR® Quality Grade is a DNA genetic marker panel test which identifies the presence of four major genes associated with Quality Grade and marbling. The third and fourth markers in this panel were released as of February 15, 2007. This Panel Test includes TG5, which was the first gene marker test available to the beef industry. Each of the four gene markers in this panel have been found to be highly associated with quality grade in multiple evaluations across multiple breeds of cattle. Click here to learn more about the GeneStar Quality Grade testing.
GPDs™ are a logical, simple calculation used to describe the actual genetic makeup of animals. GPDs are designed to accommodate an infinite number of genetic combinations, interactions, and genes yet to be discovered.
The numerical value for GeneSTAR Tenderness, for example, is reported in pounds of shear force (WBSF) and is derived from independent third party validation results, including the NBCEC (National Beef Cattle Evaluation Consortium). An animal with one Star for T1, one Star for T2, and two Stars for T3 shows a difference in shear force of -1.5 pounds, as compared to an animal with no markers for Tenderness.
For Quality Grade markers, a GPD is reported as the increased likelihood that a carcass will grade Choice or better, and is also derived from independent third party validation results including the NBCEC. An animal with two Stars for QG1, and one Star for QG2 would be 20% more likely to have a Choice or better Quality Grade over an animal with no Quality Grade markers. For this animal the Quality Grade GPD would be +20.0.
GPDs should always be used in conjunction with respective Breed Association EPDs for a complete picture of all known and predicted genetic merit. For instance, when comparing two bulls with similar EPDs, GPDs can be used to distinguish between the two bulls by comparing the identified genetic differences in each bull (GPDs), beyond their statistically calculated Expected Progeny Differences (EPDs).
November 3, 2007 issue
by Alison Van Eeneennaam, Coop Ext Specialist, UC, Davis
"The National Beef Cattle Evaluation Consortium (NBCEC) Advisory
Council, made up of ten representatives from industry stakeholder
organizations, including Beef Improvement Federation, the National
Cattlemen's Beef Association (NCBA) and the U.S. Beef Breeds Council,
were concerned about the reliability of DNA tests being marketed to
beef cattle producers and asked the NBCEC to develop a process to
verify that commercial DNA tests worked in accordance with company
"This resulted in the development of the NBCEC commercial test
validation process. This independent validation process was designed
to evaluate the associations between genetic tests and traits as
claimed by commercial genotyping companies. Most of the initial DNA
tests being commercialized for use in beef cattle were for carcass
characteristics, and DNA and phenotypes from the NCBA Carcass Merit
Project (CMP) reference cattle populations were used for the
validation. These populations represent a cross-section of commercial
cattle sired by prominent bulls from various breeds raised under
different management practices and environmental conditions. Such
diversity of breeds and environments is likely to be typical of
commercial applications of DNA testing.
"Three commercially available DNA marker tests for carcass quality
traits have been independently validated by the NBCEC as of 8/31/07.
Results are available at: www.nbcec.org
"GeneSTAR Quality Grade is a DNA genetic marker panel test comprised
of four markers associated with an increase in marbling score and
quality grade (% Choice and Prime) in company trials. Favorable forms
of these markers were associated with improved quality grade in an
NBCEC validation study.
"GeneSTAR Tenderness is a DNA genetic marker panel test comprised of
three markers associated with tenderness. Favorable forms of these
markers have been associated with increased tenderness in company
trials, and this finding was validated by NBCEC."
FLAVOR AND JUICINESS
"...Like tenderness, both juiciness and flavor are closely aligned with marbling. In fact, marbling scores alone explain 12% of the variation in beef palatability, according to the University of Illinois Extension Service... While the scientists do the research, what can producers do? They can produce well-marbled beef." - Drovers
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