EATING QUALITY OF BEEF FROM YOUNG HEREFORD BULLS AS INFLUENCED BY SLAUGHTER WEIGHT

Abstract

Objective measurements and subjective evaluations of the eating quality of semitendinosus (ST) and longissimus dorsi (LD) roasts were determined for 32 young (12 to 22-mo) purebred Hereford bulls (four groups of eight) fed a high concentrate ration free choice and slaughtered at average weight of 377 kg for group I, 565 kg for group II, 624 kg for group III, 682 kg for group IV. Intramuscular fat as determined by ether extract increased with increasing slaughter weight. Slaughter weight had no effect on most eating quality characteristics evaluated. Although some differences in palatability were determined they were not large enough to be of practical significance. There was a tendency for panelists to rate the texture (grain) of both types of roasts from slaughter weight groups I and II as superior to the texture of comparable roasts from slaughter weight groups III and IV. In addition, panelists frequently noted the presence of fat in the heaviest (group IV) samples. For ST roasts, residual connective tissue differed significantly between group I and the other weight groups which were similar. There was a slight trend toward increased percent cooking losses with increased slaughter weight but differences were only statistically significant for drip loss of ST roasts. Objective measurements of juiciness (water-holding capacity) and tenderness (Warner Bratzler Shear, Kramer Shear) supported the findings from sensory evaluation. These studies provide evidence that slaughter weight of young Hereford bulls over the range of 377 to 682 kg and 12 to 22 mo of age had only minor effects on cooking and eating quality characteristics, with all the beef samples tested rating moderately desirable to desirable.