THE INFLUENCES OF BREED OF SIRE AND SEX ON BOVINE INTRAMUSCULAR COLLAGEN CONTENT AND SOLUBILITY AFTER VARIOUS INTERVALS OF POSTMORTEM AGING

Abstract

Longissimus dorsi muscles (LD) from 104 beef carcasses of three sexes (32 bulls, 36 heifers and 36 steers) and three breeds of sire (37 Charolais, 33 Simmental and 34 Chianina) ranging in chronological age from 11 to 15 mo and with carcass weights approximating 270 kg were sampled at various postmortem intervals (1, 24, 144, 312 and 480 h) to evaluate the influences of sex and breed of sire upon intramuscular collagen content and solubility. Although statistically significant differences were observed in LD intramuscular collagen content among breed of sire groups at different postmortem sampling periods, they did not appear to be of practical significance. Significant differences were observed among sex groups in LD intramuscular collagen content and solbility. Carcasses from intact males consistently had more LD intramuscular collagen than carcasses from females, and the LD intramuscular collagen of bull carcasses was most heat soluble during the early postmortem period, while the heat solubility of LD intramuscular collagen in steer and heifer carcasses increased during postmortem aging. Key words: Beef, collagen, breed, sex, aging