Date of Award
Master of Science
Robert R. Shrode
Robert L. Murohree, J. B. McLaren
Two hundred and eight Angus calves and 140 Hereford calves were subjectively scored on a discrete scale from one to five for resistance to restraint in a squeeze chute. Calves of the 1970 crop were scored at an average age of 375 days (postweaning). The 1971 calves were scored at average ages of 142 (preweaning) and 241 (weaning) days. Location and breed effects on score for restraint resistance (or chute behavior) were completely confounded since the Angus were at one branch experiment station and the Herefords at another. The Angus calves had the highest average score at all observation times with the smallest difference between the two groups occurring at postweaning. Least-squares means for heifer behavior scores were higher than those for bulls at each observation time. There appeared to be a trend for behavior score to increase with age in the preweaning calves. The opposite trend was found in the older age groups. Partial correlations of behavior with weight, type, condition and average daily gain were mostly negative. However, none of the corre-lations calculated were significantly different from zero. Estimates of heritability of behavior score in the two groups averaged together were 0.091, 0.298 and 0.384 for preweaning, weaning and postweaning, respectively. These estimates appear to be in the same range as those reported for reproductive traits which are, as is the trait studied here, hormonally influenced.
Stricklin, William Ray, "An analysis of the responses of young beef cattle to restraint in a squeeze chute. " Master's Thesis, University of Tennessee, 1972.