Journal or Book Title
Journal of Animal Science
The objective was to evaluate chemical, mechanical, and sensory attributes associated with tenderness in divergent cattle breeds—Wagyu (W; n = 12), Limousin (L; n = 12) and F1-cross (W×L; n = 12)—fed two dietary treatments (0 or 6% sunflower oil (DM basis)). A randomized complete block repeated measures design in a 3 × 2 factorial arrangement of treatments was used, and effects of breed, diet, block, and associated interactions were tested. Cattle were fed barley-based diets for an average of 259 d. Twenty-four hours postmortem (PM), steaks from the longissimus muscle (LM) were sliced, vacuum-packaged, aged (1, 3, 7, 14, 28, and 56 d PM) at 2°C, and frozen (−40°C) until analyzed. Wagyu steaks had lower (P < 0.05) Warner-Bratzler shear force (WBSF) values than L steaks across all aging times. At 1 d PM, W steaks required slightly more (P > 0.05) force to shear than W×L or L (0.30 and 0.11 kg, respectively); however, by d 14 PM, W steaks required 0.77 kg less (P < 0.05) force to shear than L. Wagyu steaks received higher (P < 0.05) sensory panel sustained tenderness scores at d 14 PM than L. The pH decline was slower (P < 0.05), and temperature decline more (P < 0.05) rapid, in W carcasses than L or W×L carcasses. Breed and diet did not affect (P > 0.10) free calcium levels (FCL) over time (0, 1, 3, 7, and 14 d PM), 0-h calpastatin activity (CA), d-1 percent collagen (OH-PRO), or d-1 collagen cross-linking (HP). Western blot analysis for the presence of the troponin-T (TNT) 30-kDa fragment, conducted only on samples from steers fed the 0% sunflower oil diet, demonstrated more proteolysis by d 3 PM in L than W or W×L. Overall, breed differences in mechanical and sensory measures of tenderness were not explained by FCL, CA, OH-Pro, and HP. Even though the initial appearance of the TNT 30-kDa fragment was greater in L, linear slopes for appearance of TNT degradation product across aging time were greater for W and W×L (P < 0.01 and P = 0.056, respectively) than for L, suggesting that tenderness differences due to breed may have been facilitated by more-rapid proteolytic degradation over time.
American Society of Animal Science
Kuber, P. S.; Busboom, J. R.; Huff-Lonergan, Elisabeth J.; Duckett, S. K.; Mir, P. S.; McCormick, R. J.; Dodson, M. V.; Gaskins, C. T.; Conrath, J. D.; Marks, D. J.; and Reeves, J. J., "Effects of biological type and dietary fat treatment on factors associated with tenderness: II. Measurements on beef semitendinosus muscle" (2004). Animal Science Publications. 45.