Submitted to: American Meat Science Association Conference Reciprocal Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: May 5, 2009
Publication Date: June 21, 2009
Citation: King, D.A., Shackelford, S.D., Kuehn, L.A., Wheeler, T.L., Thallman, R.M. 2009. Heritability Estimates of Beef Lean Color Stability. Proceedings Reciprocal Meat Conference 61:92. Interpretive Summary: Not required.
Technical Abstract: Anecdotal evidence suggests that some carcasses produce cuts with insufficient lean color stability to meet specifications for case-ready programs. The source of animal-to-animal variation in lean color stability has not been adequately characterized to determine a suitable solution to this issue. Our objective was to determine the genetic contribution to lean color stability of beef produced by a crossbred cattle population representing the most commonly used breeds in the industry. Sires were sampled from seven breeds (Angus, Charolais, Gelbvieh, Hereford, Limousin, Red Angus, and Simmental) to produce F1 bulls and heifers. These animals were multi-sire mated to create F1 x F1 (F1-squared) steer progeny (n = 464 over two years), which were fed a corn-based diet, serially slaughtered, and subsequently evaluated for lean color and lean color stability. Thirty-two sires produced progeny (average of 14.4 progeny per sire) used in this experiment. Parentage was verified using SNP-based markers. At 18 d postmortem, one longissimus thoracis steak obtained from each animal was packaged in PVC-overwrap and placed in simulated retail display for 6 d. Instrumental color measurements (L*, a*, b*, and spectral data) were collected on d 0 and d 6 of display. These data were also used to calculate the change in chroma, overall color change, and K/S 572:K/S 525 (surface metmyoglobin) during display. Initial L* (lightness), a* (redness), and b* (yellowness) values were 48.6 ± 0.14, 33.7 ± 0.07, 26.5 ± 0.09, respectively. Final values of L*, a*, and b* were 47.1 ± 0.15, 26.6 ± 0.12, 21.4 ± 0.09, respectively. At the initiation of display, 24% of the variation in L* values could be explained genetically. By day 6, 40% of L* variation could be explained by genetics. Neither a* nor b* values were heritable when measured on day 0; but genetic contributions to d 6 measurements could account for 14 and 13% of variation in a* and b*, respectively. Change in L* values was not heritable. The changes in a* and b* between d 0 and d 6 were more heritable than the values measured either before or after display. Changes in color intensity (chroma), redness (a*), overall color change (delta E), and the accumulation of surface metmyoglobin (K/S 572:K/S 525) were moderately heritable. Greater heritability estimates associated with the changes in these variables suggest that the genetic contribution to lean color is more related to the ability to maintain lean color rather than determining initial color. These heritability estimates suggest that genetic selection could potentially be used to increase the color stability of meat products.