THE ADRENOCORTICOTROPIC HORMONE STIMULATION TEST - ITS POTENTIAL USE AND LIMITATIONS IN RED DEER (CERVUS-ELAPHUS)

The adrenocorticotrophic hormone (ACTH) stimulation test was assessed in red deer (Cervus elaphus). Following injection (i.v.) of 0, 100, 250, or 500 mu g synthetic ACTH in farmed hinds (5 per group; mean live mass 78 kg), peak plasma cortisol concentrations occurred 30 min later. There was no dose effect on the peak levels attained, but the duration of the response increased with dose. The response of wild hinds (mean live mass 64 kg) to 500 pg ACTH administered at the time of capture was studied. Plasma cortisol concentrations were high prior to ACTH administration (238 +/- 17.6 nmol/L; mean +/- SE). Eighty minutes later, although concentrations were lower overall, they were significantly higher in ACTH-treated than in control animals (21 per group). Twenty farmed male red deer calves (aged 5 months at the outset; mean live mass 44 kg) were permanently housed after weaning. One hundred micrograms of ACTH was injected at weeks 0 (just after weaning) and 12. At week 12 mean cortisol concentrations were lower both before and after ACTH injection, although ACTH significantly increased plasma cortisol concentration on both occasions. Together these experiments suggest that the ACTH stimulation test can be employed in some classes of red deer but that it is not appropriate when animals have a high initial plasma cortisol concentration.