Effect of Marbling on Variation and Change in Beef Tenderness In \u3ci\u3eBos Taurus\u3c/i\u3e and \u3ci\u3eBos Indicus\u3c/i\u3e Crosses

Today\u27s diet conscious consumers continue to desire flavorful, tender meat, but increasingly avoid excess fat. Differences in USDA quality grades within similar aged cattle are determined primarily by differences in marbling scores which tend to be associated with overall fatness in beef carcasses. Previous studies (Cundiff et al., 1988) demonstrated an antagonism between lean yield in carcasses and degree of marbling associated with higher quality grades. Breeds that rank highest for retail product percentage rank lowest for marbling. High negative genetic correlations have been found within breeds between marbling and retail product percentage. Thus, only limited opportunity exists for genetically increasing marbling without increasing fat trim and reducing retail product percentage. Nevertheless, there is a large amount of variation in palatability characteristics among animals with the same degree of marbling, suggesting the importance of factors other than marbling have a large impact on eating qualities. Concern with the antagonism between marbling and retail product percentage is justified to the extent that a certain amount of marbling is required to ensure papatability of the retail product. This report summarizes the sensory tenderness evaluations associated with marbling scores from steer carcasses produced in the Germplasm Evaluation Program at the U.S. Meat Animal Research Cente