EFFECTS OF CASTRATION AND ELECTRICAL STIMULATION ON BEEF CARCASS QUALITY AND PALATABILITY CHARACTERISTICS

Authors

S. Kalstrup, Danish Meat Research Institute
H. R. Cross, Texas A & M University - College Station
B. D. Schanbacher, USDA-ARS
R. W. Mandigo, USDA-ARSFollow

Date of this Version

1984

Comments

Published in Journal of Animal Science (1984) 58:1, 75-84

Abstract

Thirty bull and 30 heifer Hereford x Simmental calves were weaned at approximately 5 mo of age and assigned randomly to one of the following treatments: intact, conventionally castrated or luteinizing hormone-releasing hormone-immunized (LHRH). All animals were slaughtered at 16 mo of age and the right side of each carcass was electrically stimulated (ES) or restimulated (RES). Yield and quality grades were determined on both right and left sides after 24 h chilling. Longissimus muscles (LD) were obtained at 7 d postmortem for objective color measurements, chemical analysis, shear force and trained sensory panel evaluation. Semitendinosus muscles (ST) were also obtained at 7 d postmortem for shear evaluation. Differences among the three male groups in quality grade scores and lean color were nonsignificant, but bull and LHRH-bull carcasses were leaner with a higher percentage protein when compared with steer carcasses. Shear values for both LD and ST muscles indicated that steers had more tender meat than bulls and LHRH-treated males. Collagen content and sensory panel scores for tenderness were only slightly in favor of the steers. Ovariectomized heifers had less subcutaneous fat and were rated more tender by the sensory panel than intact and LHRH-treated females. The LHRH-treated females had higher shear values for the LD muscle. These were the only differences in carcass and meat characteristics among the three female groups. Females had slightly higher yield grades, higher USDA quality grades and were fatter than steers. Electrical stimulation resulted in less severe 'heat ring' formation, more youthful lean maturity scores, brighter lean color and improved shear values of ST meat. Electrical stimulation had no effect on tenderness of LD meat, Sex × stimulation interactions were due to a better response of steers to ES than in the other groups.