Bilateral Symmetry of the Pork Carcass

Abstract

Twenty pigs of three breeds were selected to represent equally two sexes and two market weight groups. The pigs were slaughtered and after the carcasses were chilled they were carefully split into left and right sides. From each side the adductor, biceps femoris, gastrocnemius, quadriceps femoris, semimembranosus and semitendinosus of the pelvic limb; the longissimus of the back; the supraspinatus and triceps brachii of the thoracic limb and the femur were freed of external fat and tendons and individually weighed. Each muscle was analyzed for total fat by solvent extraction. Cross-sectional areas of the longissimus were measured between the 10th and 11th and between the 12th and 13th costae. Sex, live market weight and carcass side had no significant effect on differences of characteristics determined on right and left sides. Thus, bilateral asymmetry was not detected, and the difference from left to right sides (approximately 8%) may be wholly attributable to experimental error. The standard deviation of each side-to-side difference is reported as a percent of the single-side average value. Copyright © 1964. American Society of Animal Science . Copyright 1964 by American Society of Animal Science