|Burdick, Nicole -|
|Willard, Scott -|
|Vann, Rhonda -|
|Welsh Jr, Tom -|
|Randel, Ron -|
Submitted to: Livestock Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 25, 2010
Publication Date: February 25, 2010
Citation: Burdick, N., Carroll, J.A., Hulbert, L.E., Dailey, J.W., Willard, S., Vann, R., Welsh Jr, T., Randel, R. 2010. Relationships between temperament and transportation with rectal temperature and serum concentrations of cortisol and epinephrine in bulls. Livestock Science. 129:166-172. Interpretive Summary: A collaborative study was conducted involving scientists from the Livestock Issues Research Unit, Texas AgriLife Research and Extension Center-Overton, Texas AgriLife Research-College Station, and Mississippi State University to elucidate the stress hormone profiles in cattle with various temperaments in response to being transported. While previous studies have indicated that transportation is stressful to cattle, limited information is available on the effect of transportation on changes in rectal temperature in cattle which do not have the influence of human presence during the data collection. Therefore, this study was designed to determine the influence of temperament on rectal temperature recorded without human presence and secretion of cortisol and epinephrine in bulls in response to transportation. Results indicate that maximum and minimum rectal temperature were positively correlated to the temperament of the animal, and that epinephrine tended to be positively correlated with maximum rectal temperature. Additionally, both stress hormones, cortisol and epinephrine, were positively correlated with the temperament of the cattle. Collectively, these data demonstrated that temperamental bulls had greater concentrations of cortisol and epinephrine and also had elevated rectal temperature compared to the calm bulls. Additionally, these data elucidate dynamic changes in rectal temperature to various stimuli including transportation and handling.
Technical Abstract: This study investigated whether temperament influences rectal temperature and the secretion of cortisol and epinephrine in response to transportation. Brahman bulls were selected based on temperament score (average of exit velocity, EV, and pen score, PS) measured 28 days prior to weaning with the 8 most Calm (0.89 ± 0.15 EV and 1.00 ± 0.00 PS), 8 most Temperamental (3.70 ± 0.29 EV and 4.88 ± 0.13 PS), and the 8 most Intermediate (1.59 ± 0.12 EV and 2.25 ± 0.16 PS) selected from a pool of 60 bulls. Whole blood was collected pre- and post-transport, and rectal temperature recording devices were inserted pre-transport for continual collection of rectal temperature during transport. Bulls were transported in a trailer 770 km from Overton, TX (32.27 N, -94.98 W, 153 m altitude) to New Deal, TX (33.74 N, -101.84 W, 1006 m altitude). Serum cortisol and plasma epinephrine concentrations were determined. Prior to transportation (0 min), Temperamental bulls had greater rectal temperature than Calm or Intermediate bulls (P < 0.05). Rectal temperature peaked within 30 min after the onset of transportation with Temperamental bulls having greater peak rectal temperatures than Calm or Intermediate bulls (P < 0.05). The lowest mean rectal temperature was reached 400 min after the onset of transportation with Calm bulls having lower mean rectal temperatures than Intermediate or Temperamental bulls (P < 0.05). Prior to transportation, Temperamental bulls had greater cortisol concentrations than Calm bulls (P < 0.05). Temperamental bulls had greater concentrations of epinephrine prior to transportation than Calm or Intermediate bulls (P < 0.05). Temperamental bulls also had greater concentrations of cortisol and epinephrine post-transportation than Calm bulls (P < 0.05). Maximum and minimum rectal temperature were positively correlated (r = 0.73; P < 0.01). There was a positive correlation between EV and maximum rectal temperature (r = 0.62; P = 0.01), and a trend for EV to be positively correlated with minimum rectal temperature (r = 0.43; P = 0.10). Epinephrine tended to be positively correlated with maximum rectal temperature (r = 0.46; P = 0.06). Both cortisol (pre-transportation r = 0.55; P = 0.02) and epinephrine (pre- and post-transportation, r = 0.64; P < 0.01 and r = 0.59; P < 0.01, respectively) were positively correlated with EV. In summary, temperament was predictive of 1) changes in rectal temperature due to transportation and 2) circulating concentrations of cortisol and epinephrine before and after transportation.