Estimation of Amounts and Proportions of Muscle and Edible Meat in Beef Carcass by Carcass Measurements and Carcass Fat Scores

Abstract

Carcass measurements on carcass length, width, thickness and girth, and carcass fat scores valuated as a degree of subcutaneous fat deposition in three parts of carcass were used for an estimation of amounts and proportions of muscle and edible meat in carcasses by a stepwise regression analysis. Steer carcasses used were 107 and consisted of two strains of Japanese Black, Holestein, Japanese Shorthorn and Crossbred between Japanese Black (75%) and Holstein (25%). Carcasses were dissected and the amounts of edible meat were adjusted on the basis of the amount of fat and muscle in each wholesale cuts. Carcass fat scores correlated better to the proportion of carcass fat than to the weight of fat in carcass. Carcass weight explained 0.87 and 0.89% of the total variances of muscle and edible meat weights in carcass, respectively, and carcass measurements and carcass fat scores were not effective for an improvement of the determination coefficients of the regression equations. On the contrary, the proportions of muscle and edible meat in carcass were explained effectively by the carcass measurements and carcass fat scores, and the carcass weight was not so effective. Breed was an important factor for the improvement of the determination coefficients of the regression equations. But the independent variables entered into the equations differed greatly among breeds.