USING DNA MARKERS

You’ve no doubt been bombarded with new information about using DNA markers to select cattle for several carcass traits, including tenderness. We at Effertz Key Ranch welcome this exciting and accurate new technology. We’re testing much of our seedstock for tenderness because Effertz Key Ranch believes that providing consumers with a satisfying eating experience is the one thing more important than producing beef efficiently and profitably.

That said, if you have “stars” in your eyes trying to figure out what’s real and what’s hype about this new DNA technology, you’re not alone. Because of the vast amount of confusing and misleading information out there, we at Effertz Key Ranch decided to try to corral the facts. Here’s both the long and short on the subject. If you’re in a rush (and who isn’t), feel free to hit just the highlights on this page. If and when you’re ready to dig deeper, click on the READ MORE at the end of every question for a more in-depth answer. You can also click on any of the attached files listed in the READ MORE sections for additional information about that subject. You’ll need the Adobe reader program to read the attached articles.
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TEN TENDER HIGHLIGHTS

1. Why worry about tenderness?

It’s crucial for customer acceptance and consumers are willing to pay more for tender beef.
Chemically or mechanically enhancing beef doesn’t fix the problem if you start with tough product to begin with. And consumers don’t like us tampering with it.
Because of instrument grading and new testing technology, tenderness is going to soon be a part of grid premiums and discounts. What you do now will determine whether there are “tender” premiums or “tough” discounts in your future. (READ MORE).

2. Doesn’t marbling or quality grade get at the same thing?

No. Marbling accounts for no more than 10% of the variation in tenderness. What’s more, a significant amount of Select beef tests tender and a significant amount of Choice beef, even the top two-thirds of Choice, tests tough. (READ MORE).

Also (click here) to read an excerpt from USDA Meat Animal Research Center report on Marbling Effect on Beef Cattle Palatability.

3. How do I shop for genetically tender seedstock?

Effertz Key Ranch has several sons and daughters of DNA-verified tender sires as well as semen available. For more information: [Salers], [Charolais] (click on one).

There are two commercially available DNA tests for tenderness: Merial’s Igenity® (formerly called TenderGENE™) www.igenity.com

and Bovigen’s GeneSTAR® test. http://www.bovigen.com/tenderness.htm

Both tests have been independently evaluated by the National Beef Cattle Evaluation Consortium (NBCEC) to have a “highly” significant effect on beef tenderness and both are similar. But Igenity® reports its results in a scoring system from 1 to 10 and in the U.S., GeneSTAR® has a possible 6 stars for tenderness and another two possible stars for marbling. (READ MORE).

A 5 STAR BULL IN AUSTRALIA MIGHT BE NO MORE THAN A 3 STAR BULL IN THE U.S. GENESTAR® AUSTRALIA REPORTS AS MANY AS 8 STARS FOR TENDERNESS BUT THE ADDITIONAL TWO STARS COME FROM A MARKER THAT HAS NOT YET BEEN PROVEN TO BE STATISTICALLY SIGNIFICANT FOR TENDERNESS AND IS THEREFORE NOT CURRENTLY MARKETED IN THE U.S.

THERE IS ALSO AN ADDITIONAL MARBLING MARKER USED IN AUSTRALIA THAT CAN EARN A BULL ANOTHER TWO STARS MAKING A TOTAL OF 14 STARS (8 FOR TENDERNESS AND 6 FOR MARBLING) POSSIBLE IN THAT COUNTRY. BUT THIS ADDITIONAL MARBLING MARKER HAS ALSO NOT BEEN SHOWN TO BE STATISTICALLY SIGNIFICANT AND IS NOT MARKETED IN THE U.S.

4. Why aren’t all stars created equal?

GeneSTAR®’s marbling stars (there are two possible) shouldn’t be added to or confused with its tenderness stars. While the tenderness test was independently evaluated to be highly significant, the marbling test didn’t meet normal statistical significance. What’s more adding them together tells you nothing about tenderness or marbling. (READ MORE).

5. Do Igenity®’s score and GeneSTAR®’s stars mean the same thing?

To a point. Two of the three markers that each company is using in their tenderness test are identical. The third marker, although a different SNP, has been verified to have a similar effect and is likely measuring the same gene. But the two companies report the test results so differently that an animal with a score less than 10 or having less than six stars can not be compared to each other without more specific information about the actual genotype of each marker (READ MORE).

6. Why does 6 equal 10 but 5 doesn’t equal 5?

Because only an animal that tops the scale in both tests (such as Keys McTender 279P—who is a 10 on Igenity®’s tests and has 6 stars on GeneSTAR®’s test) can be compared. That’s because he has the most favorable genotype for all the tenderness markers available. But these animals are rare in any breed. Under the GeneSTAR® system, it’s possible for animals to earn the same number of stars and yet have very different genotypes for tenderness or marbling. (READ MORE).

7. What’s a marker and other smart questions?

Sorry, no short cuts here. (READ MORE) for the answers. This section also includes a table of the favorable and unfavorable tenderness markers for both the Igenity® and GeneSTAR® tests.

8. When is a one pound difference a big deal?

When it’s a shear force difference. Warner Bratzler shear force is the gold standard for objectively measuring tenderness because it measures the force or pressure needed to slice beef cooked to a standard medium doneness. Generally beef needing over 11 lb. of shear force is considered tough. A 1 lb. difference in shear force is highly significant and could easily be enough to more an animal from slightly tough to tender. Based on research results, Igenity® assigned shear force value differences to each of its 10 scores. (READ MORE) . This section shows those values and demonstrates the similarities and important differences between the Igenity® and GeneSTAR® rating systems.

9. Why does it make a difference where the “stars” come from?

Because a five star bull on the GeneSTAR® system could actually have only one favorable allele for each of the three tenderness markers and the two marbling markers. You’ve not only been misled about the tenderness status of this bull, but his “starry” total was obtained by adding the highly significant stars for tenderness to the statistically “shaky” stars for marbling. (READ MORE).

10. Think your cattle are tender enough?

Regardless of breed, animals that score 7 or above for tenderness aren’t all that prevalent. As this chart in this section shows, we’ve got plenty of room for improvement. (READ MORE). This section also contains links to independent research on breed shear force differences as well as the relationship between tenderness, marbling and eating satisfaction.

Effertz Key Ranch has several sons and daughters of DNA-verified tender sires as well as semen available. For more information: [Salers], [Charolais] (click on one).