The Heritability of Factors that Influence Tenderness in Beef Cattle

The heritability, phenotypic correlations and genetic correlations of 63 factors were determined in this study. The traits studied (with their heritabilities and standard errors in parenthesis) included: days on feed (1.00 ± 0.116), longissimus muscle area (0.85 ± 0.183), marbling (0.83 ± 0.170), adjusted preliminary yield grade (0.61 ± 0.156), quality grade (0.59 ± 0.148), yield grade (0.56 ± 0.150), preliminary yield grade (0.48 ± 0.143), muscle score (0.44 ± 0.140), 21-day Warner-Bratzler Shear force (0.42 ± 0.148), 3-day initial juiciness (0.42 ± 0.148), hump height (0.40 ± 0.141), 7-day Warner-Bratzler Shear force (0.37 ± 0.147), 7-day initial tenderness (0.37 ± 0.140), 48-hour temperature (0.35 ± 0.121), lean color (0.34 ± 0.122), 14-day sustained tenderness (0.33 ± 0.135), 3-day initial tenderness (0.32 ± 0.131), 3-day sustained tenderness (0. 31 ± 0.129), 7-day sustained tenderness (0.31 ± 0.129), a* (0.29 ± 0.115), 3-hour temperature (0.29 ± 0.114), 14-day initial tenderness (0.28 ± 0.126), 14-day Warner-Bratzler Shear force (0.28 ± 0.121), b* (0.28 ± 0.120), final weight (0.26 ± 0.113), m-calpain (0.24 ± 0.195), 3-day overall mouthfeel (0.24 ± 0.119), 3-day Warner-Bratzler Shear force (0.23 ± 0.114), kidney, pelvic and heart fat (0.23 ± 0.107), temperament (0.23 ± 0.094), 3-day flavor intensity (0.22 ± 0.114), average daily gain (0.22 ± 0.105), 21-day initial tenderness (0.19 ± 0.110), frame score (0.19 ± .097), 21-day beef flavor (0.18 ± 0.110), 14-day overall mouthfeel (0.18 ± 0.107),14-day sustained juiciness (0.18 ± 0.105), μ-calpain (0.17 ± 0.197), 14-day initial juiciness (0.17 ± 0.104), lean firmness (0.17 ± 0.094), 21-day sustained tenderness (0.16 ± 0.108), 48-hour pH (0.16 ± 0.097), hot carcass weight (0.15 ± 0.091), 7-day overall mouthfeel (0.14 ± 0.097), 14-day beef flavor (0.12 ± 0.097), calpastatin (0.11 ± 0.095), 14-day flavor intensity (0.11 ± 0.094), 21-day flavor intensity (0.10 ± 0.087), lean texture (0.10 ± 0.086), initial weight (0.10 ± 0.078), L* (0.09 ± 0.087), 7-day flavor intensity (0.06 ± 0.081), 3-hour pH (0.06 ± 0.073), 3-day sustained juiciness (0.05 ± 0.081), heat ring (0.05 ± 0.061), 21-day overall mouthfeel (0.02 ± 0.076), 3-day beef flavor (0.01 ± 0.072), 7-day sustained juiciness (0.01 ± 0.062), 21-day sustained juiciness (0.00 ± 0.089), 7-day beef flavor (0.00 ± 0.080), sarcomere length (0.00 ± 0.075), 21-day initial juiciness (0.00 ± 0.072) and 7-day initial juiciness (0.00 ± 0.062). Phenotypic correlations and their respective p-values were determined and reported for all 3,969 relationships. Genetic correlations (n = 276) were determined for traits that were heritable including correlations for tenderness traits such as m-calpain activity, calpastatin activity, 48-hour pH, 48-hour carcass temperature, and marbling. Other genetic correlations studied included extensive sensory taste panel traits including 3-, 7- ,14- and 21-day initial tenderness, sustained tenderness, initial juiciness, sustained juiciness, flavor intensity, beef flavor and overall mouthfeel. The genetic correlations of color traits were also determined including Hunter colorimeter readings for a* and b*, as well as, subjective lean color scores. Other carcass traits studied using genetic correlations included lean texture, lean firmness, yield grade, hot carcass weight, and longissimus muscle area. Genetic correlations for 21-day Warner-Bratzler shear force, temperament, breed type and hump height were also determined.