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Functional characteristics of the bovine hypothalamic-pituitary-adrenal axis vary with temperament.
- Source :
-
Hormones and behavior [Horm Behav] 2008 Jan; Vol. 53 (1), pp. 20-7. Date of Electronic Publication: 2007 Aug 24. - Publication Year :
- 2008
-
Abstract
- Hypothalamic-pituitary-adrenal (HPA) axis function, in Brahman heifers of differing temperament, was evaluated using separate challenges with CRH and ACTH. Exit velocity (EV) measurement was used to classify heifer temperament as calm [C; consisted of 6 slowest heifers (EV=1.05+/-0.05 m/s)] or temperamental [T; 6 fastest heifers (EV=3.14+/-0.22 m/s)]. During the 6 h prior to CRH challenge, areas under the ACTH (P=0.025) and cortisol (P<0.001) curves were greater in the temperamental heifers. Baseline cortisol (P<0.001) but not ACTH (P=0.10) differed between temperament groups. Following CRH challenge, areas under the ACTH (P=0.057) and cortisol (P<0.01) response curves were greater in the calm animals. The same animals were subjected to an ACTH challenge 14 d following their utilization in the CRH stimulation experiment. Prior to ACTH challenge, baseline cortisol concentrations were higher (P<0.001) in the temperamental heifers (T=18+/-2.6, C=4.3+/-0.6 ng/mL). Following ACTH administration, area under the cortisol response curve was greater (P=0.07) in the calm heifers. After declining below baseline concentrations during the post-challenge recovery period, cortisol in temperamental animals was again greater (P=0.02) than in the calm heifers. These data demonstrate that cattle with an excitable temperament exhibit increased stress responsiveness to handling, increased baseline adrenal function but not increased basal pituitary function, and a muted responsiveness to pharmacological stimulus. Thus, functional characteristics of the HPA axis vary with animal temperament.
- Subjects :
- Analysis of Variance
Animals
Area Under Curve
Cattle
Corticotropin-Releasing Hormone physiology
Emotions physiology
Female
Stimulation, Chemical
Time Factors
Adrenocorticotropic Hormone blood
Hydrocortisone blood
Hypothalamo-Hypophyseal System physiology
Pituitary-Adrenal System physiology
Temperament physiology
Subjects
Details
- Language :
- English
- ISSN :
- 0018-506X
- Volume :
- 53
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Hormones and behavior
- Publication Type :
- Academic Journal
- Accession number :
- 17916358
- Full Text :
- https://doi.org/10.1016/j.yhbeh.2007.08.005