Factors Affecting Beef Carcass Cutability: an Evaluation of the USDA Yield Grades for Beef

Abstract

Two-hundred and eighty beef carcasses were used to provide information on retail cut yields from beef carcasses varying widely in weight, fatness and muscling. In multiple regression equations, actual carcass measurements and commonly used subjective carcass evaluations usually accounted for over 80% of the variation of these yields. Adjusted fat thickness over the ribeye, percentage of kidney, pelvic and heart fat, and ribeye area, in that order, were the most important factors for predicting carcass yields of boneless, closely trimmed retail cuts. Carcass weight also contributed significantly (P<.05) in the equations in which it was used. These are the same four factors presently used in the official yield grade standards. On the average, the carcasses had higher yields than were predicted by the yield grades. A regression equation developed from this study and based on the same factors was only slightly more highly correlated with cutability than was the equation from which the present yield grades were derived. There also was little evidence that the equation from which the present yield grade equation was derived discriminated against certain types of carcasses more than the corresponding equation developed from this study. Therefore, there would be little advantage to revising the present USDA yield grade standards for the purpose of improving the cutability predictions of the present standards.