H. Y. Chung1, M. E. Davis, H. C. Hines, and D. M. Wulf
The Ohio State University Department of Animal Sciences
Relationships of the calpain system with meat tenderness and carcass traits were examined in 47 purebred Angus bulls from two lines divergently selected for blood serum IGF-I concentration. Genotyping was performed by PCR-SSCP (single strand conformation polymorphism) and RFLP (restriction fragment length polymorphism) analysis. The primers were selected from the calpain I large subunit (CANP1L4) and calpain IV small subunit (CANP4S). Bulls from 13 to 15 months of age were slaughtered, and carcass traits, including fat thickness (FAT); longissimus muscle area (LMA); percentage of kidney, pelvic, and heart fat (KPH); hot carcass weight (HCW); marbling score (MAR); and quality grade (QUL), were measured. Activities of calpastatin (CAC), u-calpain (UCL), and m-calpain (MCL) were measured, and Warner-Bratzler Shear Force (WBS) and myofibril fragmentation index (MFI) were determined. Differences in CANP4S genotypes (BB > AB > AA) were found for KPH (P < 0.05), and IGF-I selection line influenced MFI and CAC (P < 0.05). CAC was higher in the low line than in the high line, but MFI was higher in the high line. Strong positive residual correlations were detected between CAC and UCL, MCL and MAR, MCL and QUL, and MAR and QUL (P < 0.05). Negative relationships were detected between CAC and FAT with r = -0.56 (P < 0.05), and between UCL and MFI with r = -0.99 (P < 0.05). It may be possible to use calpain genotypes classified by PCR-SSCP and RFLP procedures in marker-assisted selection programs to improve meat tenderness and carcass traits of beef cattle.
1 For more information, contact at: The Ohio State University, 221 Plumb Hall, 2027 Coffey Road, Columbus, OH 43210, 614-292-4984, Fax 614-292-7116, e-mail: davis.28@osu.edu