PRESLAUGHTER MANAGEMENT AND DARK-CUTTING IN THE CARCASSES OF YOUNG BULLS

Abstract

One hundred-and-twelve yearling bulls were penned together for at least 3 mo in groups of 7 or 21. They were then shipped 150 km to an abattoir in groups of either 7 or 21, and were either regrouped or not regrouped before shipment. They were held overnight at the abattoir before slaughter. A further seven yearling bulls were shipped and held individually before slaughter. After slaughter, muscle color was appraised by Federal graders. Load size had no significant effect on the incidence of dark-cutting, but regrouping had a dramatic effect (73 vs. 2% dark cutters, P < 0.01). There were no dark cutters among the bulls shipped individually. It is concluded that agonistic encounters among regrouped bulls was a far more important cause of dark-cutting than either load size or exposure to an alien environment.