Re-establishment of the stress response in Gallus domesticus after hatching.
Cold caused a hypercorticosteronaemia and hypothermia in the 2-day-old chick. Heat did not affect plasma corticosterone concentrations, despite the birds becoming hyperthermic. The 2-day-old chick has a lower resting concentration of corticosterone than the 1-day-old. The minimum effective dose of corticotrophin in stimulating a hypercorticosteronaemia was 0.5 IU/kg in the former, 1.0 IU/kg in the latter. It is concluded that stress non-responsiveness persists for about 48 hr after hatching and that it is due to a temporary inhibition of hypothalamic function.
D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D001831:Body Temperature; D002645:Chickens / Q000502:physiology*; D003080:Cold Temperature; D003345:Corticosterone / Q000097:blood; D006358:Hot Temperature; D013312:Stress, Physiological / Q000503:physiopathology*
D000324:Adrenocorticotropic Hormone; D003345:Corticosterone