BOS-INDICUS CROSS FEEDLOT CATTLE WITH EXCITABLE TEMPERAMENTS HAVE TOUGHER MEAT AND A HIGHER INCIDENCE OF BORDERLINE DARK CUTTERS

Temperament ratings based on a numerical scale (chute score) were asse ssed during weighing and handling of cattle at a feedlot. Breeds studi ed included Braford, Red Brangus and Simbrah. Cattle were fed to a con stant fat thickness of 9 to 13 mm (target = II mm) over the 12th rib a s determined by periodic ultrasound measurements. Cattle were slaughte red in a commercial slaughter plant and stunned by captive bolt. Tempe rament rating had a significant effect on the incidence of borderline dark cutters which were downgraded by a USDA grader (P=0.01). Temperam ent score also had a significant effect on tenderness (P<0.001) as eva luated by Warner-Bratzler Shear (WBS) force at day 14 post mortem. The calmest animals which stood still when restrained in a hydraulic sque eze chute had a mean WBS force of 2.86+/-11 kg and cattle which became highly agitated and struggled violently during restraint averaged 3.6 3+/-19 kg. Forty percent of these cattle had WBS force values which we re over 3.9 kg which is a threshold value for acceptability in food se rvice establishments. These data show that cattle with the most excita ble temperament ratings produce carcasses with tougher meat and a high er incidence of borderline dark cutters than cattle with calm temperam ent ratings. (C) 1997 Elsevier Science Ltd.