H. Y. Chung, M. E. Davis1, H. C. Hines, and D. M. Wulf
The Ohio State University Department of Animal Sciences
This study was designed to investigate the effects of calpastatin activity and myofibril fragmentation index on meat tenderness and the effects of calpastatin genotypes determined using PCR-SSCP (polymerase chain reaction-single strand conformation polymorphism) analysis on these variables. Forty-seven purebred Angus bulls were slaughtered at approximately 13 to 15 months of age. Longissimus muscles were prepared to determine myofibril fragmentation index (MFI), Warner-Bratzler Shear (WBS) Force, and calpastatin activity. The PCR primers for the calpastatin (CAST) segments were selected based on exons of the bovine calpastatin cDNA sequences as CAST1 (exon 1C and 1D), CAST5 (exon 5 and 6), and CAST10 (exon 10 and 11). Polymorphisms were detected in all of the calpastatin segments examined. Observed genotypes were AA, AB, and BB for CAST1 and CAST5, and AA, BB, CC, AB, AC, and BC for CAST10 segments. Statistical significance of CAST1, CAST5, and CAST10 genotypes was not detected for calpastatin activity, shear force, or myofibril fragmentation index. A weak positive residual correlation (r = 0.29, P = 0.52) between CAC and WBS was obtained. MFI and WBS were slightly related (r = -0.49, P = 0.26). There was a significant negative correlation between CAC and MFI with r = -0.74 (P = 0.05). PCR-SSCP analysis of the calpastatin locus was not useful for the prediction of calpastatin activity, myofibril fragmentation index, or meat tenderness.
1 For more information, contact at: The Ohio State University, Ohio Agricultural Research and Development Center, 221 Plumb Hall, 2027 Coffey Road, Columbus, OH 43210, 614-292-4984, Fax 614-292-7116, e-mail: davis.28@osu.edu