Location: Livestock Issues ResearchTitle: Physiological and metabolic responses of gestating Brahaman cows to repeated transportation Author
|Price, Deborah - Texas A&M University|
|Lewis, Andrew - Texas A&M University|
|Neuendorff, Don - Texas A&M University|
|Carroll, Jeffery - Jeff Carroll|
|Welsh Jr., Thomas - Texas A&M University|
|Vann, Rhonda - Mississippi State University|
|Randel, Ronald - Texas A&M University|
Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/3/2014
Publication Date: 2/20/2015
Citation: Price, D.M., Lewis, A.W., Neuendorff, D.A., Carroll, J.A., Sanchez, N.C., Welsh Jr., T.H., Vann, R.C., Randel, R.D. 2015. Physiological and metabolic responses of gestating Brahaman cows to repeated transportation. Journal of Animal Science. 93:737-745.
Interpretive Summary: This research represents a collaborative effort of scientists from Texas A&M University, the Livestock Issues Research Unit, and Mississippi State University to determine the influence of repeated transportation on gestating Brahman cows. Domestic livestock are transported at least once and sometimes multiple times during their production cycle. The transportation event, including loading and unloading, can be stressful and results in losses for the livestock industry. Additionally, temperament is known to influence the stress response in cattle, with more temperamental cattle having greater circulating concentrations of the stress hormones cortisol and epinephrine. Therefore, this study was designed to observe the physiological and metabolic influences of repeated transportation on gestating Brahman cows, and if these responses were influenced by temperament of the cow. Results from this study demonstrate that vaginal temperature was greatest on the first transport day (d 60 of gestation) compared to subsequent transport events (days 80, 100, 120, and 140 of gestation). Temperamental cows had greater cortisol and tended to have greater vaginal temperature compared to Intermediate and Calm temperament cows. Additionally, Calm and Intermediate cows appeared to acclimate to the transportation events faster than Temperamental cows. These results reflect the partial acclimation of cows to a stressor over time, and demonstrate that both temperament and the transportation process influence physiological responses to stress in gestating Brahman cows. These data will be of interest to scientists in the field of stress physiology, as well as cattle producers, and can be used to modify management practices in order to improve the well-being of gestating cows.
Technical Abstract: The purpose of this study was to examine physiological and metabolic responses to repeated transportation of gestating Brahman cows, previously classified as mature cows into temperament groups of Calm, Intermediate, or Temperamental. Brahman cows (n = 48) were subjected to 2 hours of transport (TRANS) on days 60, 80, 100, 120, and 140 +/- 5 days of gestation. Indwelling vaginal temperature (VT) monitoring devices were inserted 24 hours prior to each TRANS with VT being recorded 2 hours prior to TRANS and every 5 minutes through 30 minutes after TRANS. Serum concentrations of cortisol, glucose and non-esterified fatty acid (NEFA) were determined in samples collected before and after each TRANS event. Data were analyzed by multivariate repeated measures analysis in SAS. Serum cortisol concentrations were affected by temperament (P < 0.001), with Temperamental cows having the greater concentrations of cortisol prior to each TRANS event. All cows regardless of temperament, exhibited variation in cortisol concentrations prior to each TRANS event (P = 0.013) as well as increased cortisol concentrations after each TRANS event (P > 0.1). Peak VT was greater (P < 0.001) on d 60 of gestation relative to all other TRANS days regardless of cow temperament. During TRANS, the Temperamental cows tended (P < 0.09) to have greater peak VT (39.86 +/- 0.15C) compared to Calm (39.41 +/- 0.16 C) and Intermediate cows (39.55 +/- 0.08 C). Area under the VT curve decreased (P = 0.002) from day 60 through day 140. Pre-TRANS serum glucose concentration on day 60 of gestation was greater (P < 0.03) for Temperamental (68.13 +/- 4.31microgram/deciliter) compared to Intermediate (53.42 +/- 2.78 microgram/deciliter) and Calm cows (52.76 +/- 4.60 microgram/deciliter). Calm and Intermediate cows had greater changes in NEFA concentration between pre- and post-TRANS, while Temperamental cows showed the least change (P < 0.001). Cow VT and serum glucose concentration decreased in all temperaments (P < 0.01) with repeated TRANS; however, serum NEFA concentration post-TRANS did not vary (P > 0.10) with repeated TRANS events. Serum glucose concentrations were affected (P < 0.02) by a time by temperament interaction with Temperamental cows taking more TRANS events to decrease their change in glucose concentration compared to Calm and Intermediate cows. These results reflect the partial acclimation of cows to a stressor over time, and demonstrate that both temperament and the TRANS process influence physiological responses to stress in gestating Brahman cows.