The relationship between Bos Taurus feedlot cattle temperament and cannon bone measurements

Two groups of feedlot cattle on two different mineral supplement trials were used to assess the relationship between temperament and cannon bone measurements. The cannon bones of approximately fourteen month old crossbred Bos taurus European, Continental, and British steers (n = 135), primarily Angus, Charolais, and Hereford breeds, and 54 Charolais x Hereford heifers were measured postmortem. Postmortem measurements were taken on the left front 3rd and 4th fused metacarpal (cannon) bone. Length (middle peak of the base to the sagittal ridge) was measured with an Absolute Digimatic caliper (Mitutoyo Corp., Japan) CD12" CP, while width (lateral to medial), and thickness (cranial to caudal) measurements were taken with an Absolute Digimatic caliper model CD-8" CS. Steers were individually scored on speed of exit from the squeeze chute after physical restraint; 1 = walked, 2= trotted, and 3 = ran out of the chute. Heifers were scored on their reluctance to place their head in the head restraint: 1 = not reluctant and 2 = reluctant. Steer cannon bone thickness (P = 0.008) and width (P < 0.001) were related to the speed of exit from the chute. Steers with thicker and wider bones exited the chute at a slower pace than those with smaller cannon bones. Heifers with wider (P = 0.07) and thicker (P = 0.06) bones tended to be less likely to balk at the head restraint. Cattle with larger cannon bones were calmer than those with smaller bones. Use of physical indicators such as cannon bone size may assist producers in predicting individual cattle temperament.