GeneSTAR® Tenderness was the first multi-marker single trait test commercially available to the beef industry. In its current form, it combines three markers from two different and independent genes.
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. The impact of these two genes on tenderness has been well documented for quite some time. However, through the use of DNA tests first available from Bovigen, there is now an effective and efficient tool available to use this knowledge in making breeding and management decisions.
Tenderness is typically evaluated in research environments through the use of Warner-Bratzler shear force (WBSF) tests. Collection and evaluation of this type of data is time consuming and expensive, which makes it difficult to evaluate this trait in breeding animals at a young age or on a large scale. One of the key benefits of DNA technology is the ability to provide genetic information at a young age. This is especially true on traits relating to carcass merit.
The Tenderness Genes:
Calpain is a naturally occurring enzyme that weakens muscle fibers during the post mortem aging process and plays a major role in the overall tenderness equation.
Calpastatin is a naturally occurring enzyme that inhibits the normal tenderization process of meat during post mortem aging by acting as an antagonist to the effect of Calpain.
The combined effects of these markers account for about two and a half pounds of WBSF.
On average, the T1 marker for Calpastatin accounts for about one pound of shear force and is completely independent of the other two markers currently making up the GeneSTAR® Tenderness test. T2 and T3, both markers in the Calpain gene, also account for about one pound each, though they are not independent of each other. As a result they account for about one and a half pounds in total. So, on average, the entire Tenderness test accounts for about two and a half pounds of WBSF.
Various research studies have shown anywhere from a 1.86 lb difference to a 2.89 lb difference, including the table above which is an independent analysis by the National Beef Cattle Evaluation Consortium.
