Meat photos below are courtesy of the USDA-MARC. Click on the pictures to open a larger image. Pictured below: 0-copy beef Meat from cattle having no copies of the inactive myostatin gene. This meat has a lower lean-to-fat ratio (it's fattier) and more marbling than meat from cattle having one or two copies of the gene. Pictured below: 1-copy beef (un-trimmed) Pictured below: 2-copy beef (un-trimmed) Effects of 0 -1 -and 2 alleles of Piedmontese Myostatin on Tenderness... The link above is a USDA Research Report comparing the tenderness levels of 0-copy, 1-copy and 2-copy beef. The USDA confirms that all of the effects on tenderness in the Piedmontese breed come from the Myostatin Gene .... and not from any other genetic influence. Read more on the Beef Attributes Page.

Dr. Koohmaraie of the USDA comments on Piedmontese-myostatin affects on tenderness: Quoted from this research report: "Heritabilities and Phenotypic and Genetic Correlations for Bovine Postrigor Calpastatin Activity, Intramuscular Fat Content, Warner- Bratzler Shear Force, Retail Product Yield, and Growth Rate" by S. D. Shackelfordts, M. Koohmaraie, L. V. Cundiff, K. E. Gregory*, G. A. Rohrer", and J. W. Savell *Roman L. Hruska U.S. Meat Animal Research Center, ARS, USDA, Clay Center, NE "Piedmontese crosses had the lowest WBS (Warner Bratzler Shear Force*) despite having the second-lowest amount of IMF. Additionally, Piedmontese crosses had the fourth most calpastatin activity. Thus, these data suggest that the extreme tenderness of muscle-hypertrophied [Piedmontese] cannot be explained by variation in CA [Calpastatin] or marbling [IMF]. Further studies to elucidate the mechanism responsible for the extreme tenderness of muscle-hypertrophied [Piedmontese] cattle must be conducted." *The lower the WBS, the more tender the meat. In this study, Piedmontese ranked as most tender, followed by Pinzgauer, then Hereford, out of 11 breeds compared in the USDA-MARC GermPlasm Evaluations. Further – Piedmontese crosses had the highest retail product percent, and the second lowest IMF in this comparison. Read the full report HERE (opens as a large PDF file - download will be slow on dial-up connections). A note on Calpastatin and Calpain: Calpain, a calcium-dependent protease, has been recognized as a key player in postmortem tenderization of skeletal muscle (Koohmaraie, 1996). Calpastatin is a widely distributed endogenous inhibitor protein that specifically acts on calpain. The calpain system, and  its inhibitor, calpastatin, is believed to be the primary proteolytic enzyme system involved in postmortem tenderization of aged beef (Koohmaraie et al., 1991). Koohmaraie (1996) indicated that the degradation of structural muscle proteins by calpain is responsible for meat tenderization during postmortem storage of meat. Calpastatin activity at 24 h postmortem is inversely proportional to postmortem tenderization and accounts for a greater proportion of the variation in beef tenderness than any other single variable (Koohmaraie, 1994).

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TENDER...LEAN....HEALTHFUL ....EFFICIENT to PRODUCE

 

The North American Piedmontese Cattle Association (NAPA)

PO Box 1915

Billings, Montana, USA 59103

Email NAPA@yourlink.ca

 

Visitors Since Feb, 2003