|Chase, Chadwick - Chad|
Submitted to: Journal of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 4/10/2004
Publication Date: 6/1/2004
Citation: Riley, D.G., Chase, C.C., Coleman, S.W., Randel, R.D., Olson, T.A. Assessment of temperament at weaning in calves produced from diallel matings of angus, brahman, and romosinuano. Journal of Animal Science: Vol. 82(suppl. 1) p.6.
Technical Abstract: Objectives were to assess breed differences and estimate genetic effects for measures associated with temperament in cattle: exit velocity, speed (m/s; higher values may indicate more excitable temperament) of calves when released from a squeeze chute; chute score and pen temperament score, the subjective evaluations of calf behavior when constrained in a chute or when approached in an open pen. Scores were rated from 1 to 5; higher scores indicated increasing degrees of nervous or aggressive behavior. Calves (n = 657) were from diallel matings of Angus (A), Brahman (B), and Romosinuano (R; tropically adapted Colombian breed). Fixed effects included breed (n = 9), calf sex, year (n = 2), farm (n = 3), day of record (n = 3; 0, 24, or 72 h post-weaning). Order through the chute and calf age at weaning were covariates. Random effects were calf and sire. BB (sire and dam breed, respectively) calves had the highest values for exit velocity, chute score, and pen score (2.41 ± 0.1 m/s, 2.42 ± 0.06, 3.31 ± 0.09); all were higher (P < 0.05) than all other breed groups for chute and pen score, and had higher (P < 0.05) exit velocity than all but BA and AB. RR calves had the lowest exit velocity (1.66 ± 0.07 m/s), lower (P < 0.05) than all but AA, RA, and AR. AA calves had the lowest values for chute and pen score, lower (P < 0.05) chute score than all but RR, and lower (P < 0.05) pen score than all but RR and RA. Estimates of direct breed effects for exit velocity (P < 0.001) were 0.68 ± 0.16 m/s for Brahman and '0.49 ± 0.14 m/s for Romosinuano. Estimates of direct effects for chute and pen score were highly significant for Brahman (0.91 ± 0.1 and 1.13 ± 0.15), Angus ('0.5 ± 0.1, '0.6 ± 0.14), and Romosinuano ('0.41 ± 0.09, '0.52 ± 0.13). Estimates of heterosis (P < 0.05) were 0.21 ± 0.09 m/s (7.4%) for exit velocity for B with A, 0.12 ± 0.05 (3.1%) for chute score for A with R, and '0.18 ± 0.08 (3.2%) for pen score for R with B. Results suggest that R may be included in similar breeding programs without detrimental temperament changes. Key Words: Brahman, Romosinuano, Temperament