Technical note: Exit velocity as a measure of cattle temperament is repeatable and associated with serum concentration of cortisol in Brahman bulls1

Abstract

The objectives of this study were 1) to compare temperament assessments, using multiple techniques and over repeated observations, to gauge temperament over the long-term and 2) to evaluate the relationship of the temperament appraisals with serum concentrations of cortisol (CS). Measures of temperament were gathered over 3 repeated observations (60-d interval) of yearling, fall-born Brahman bulls (initial BW = 320 +/- 4 kg; n = 66). Temperament assessments included exit velocity (EV), which was the rate at which the bulls exited the squeeze chute and traversed a fixed distance (1.83 m); pen scores (PEN; 1 = quiet to 5 = excited), ascertained from animal behavior while penned in small groups (n = 5); and chute scores (CHUTE; 1 = quiet to 5 = excited), determined from behavioral responses to restraint on the weigh scale. Temperament measures obtained during the initial data collection (d 0) were all positively correlated (r > or = 0.35, P < 0.005) with one another. Additionally, PEN (r = 0.29, P < 0.05) and EV (r = 0.26, P < 0.05) were positively correlated with CS, whereas CHUTE was not (r = 0.09, P = 0.46). All serial EV measures were positively correlated (r > 0.31, P < 0.02). All PEN were positively correlated (r > 0.31, P < 0.01), whereas serial measures of CHUTE were not (P > 0.3). Exit velocity was positively correlated with CS within d 0 (r = 0.26, P = 0.04) and 120 (r = 0.44, P < 0.01). The EV data obtained at d 0 were transformed into a discrete variable, EV ranking (EV RANK; 1 to 3 scale), in which 1 equated to <1 SD below the mean and 3 equated to >1 SD above the mean. Mean EV (P < 0.01) decreased from d 0 (2.82 +/- 0.07 m/sec) to 120 (2.11 +/- 0.10 m/sec). Time also influenced (P < 0.01) CS; mean CS decreased between d 0 (14.6 +/- 0.7 ng/mL) and 120 (11.1 +/- 0.8 ng/mL). Measures of EV can be a valuable tool for the assessment of cattle temperament and a possible predictor of temperament and stress responsiveness to future animal handling events.

Reactivity of Nellore steers in two feedlot housing systems and its relationship with plasmatic cortisol

“…These results are similar to the findings of Crookshank et al (1979) and Curley et al (2006)-the more acquainted to the procedure the animal is, the less reaction they present. On the other hand, using flight speed (FS) as another tool to measure temperament, some authors found that FS increased slightly over time in both B. indicus and B. taurus cattle (Müller and von Keyserlingk, 2006;Petherick et al, 2002).…”

“…Temperament and stress have been closely associated, and the behavior of cattle has become a method for indicating or selecting cattle that could be more stress responsive cattle or less adaptive (Curley et al, 2006).…”

Phenotypic relationships between docility and reproduction in Angus heifers1

“…Physiological responses associated with temperament can influence the probability of cows becoming pregnant because stress hormones in the bloodstream can negatively affect the release of reproductive hormones (Cooke et al, 2009). Differences in concentrations of circulating stress hormones have been associated with differences in cattle temperament (Curley et al, 2006). Cattle with "calm" temperaments had lower serum cortisol and epinephrine concentrations than animals classified as "temperamental" at a commercial feed yard (Curley et al, 2006).…”

“…Differences in concentrations of circulating stress hormones have been associated with differences in cattle temperament (Curley et al, 2006). Cattle with "calm" temperaments had lower serum cortisol and epinephrine concentrations than animals classified as "temperamental" at a commercial feed yard (Curley et al, 2006).…”

“…Blood serum collection can provide insight into acute stressors (Curley et al, 2006). Fecal sampling can be reflective of chronic stress experienced 2 to 3 d before sampling (Huber et al, 2003).…”