Adrenocortical function testing in dairy cows and its effect on milk yield.
Administration of 6IU synthetic ACTH1-24 intravenously to six Holstein-Friesian cows resulted in a cortisol peak concentration after 1 hour of 148 +/- 34.2 ng/ml. Basal plasma cortisol concentration (4.84 +/- 0.83 ng/ml) was reached 5 hours after ACTH injection. Until 7 days after ACTH administration no effect on milk yield was recorded. So it is concluded that a dose of 6 IU ACTH1-24 is sufficient for a conspicuous release of cortisol without any alteration in milk production. This dose can be used as a standard test for the evaluation of adrenocortical function in lactating cows when administered intravenously at 9 a.m. and when plasma samples for cortisol assay are collected just prior to administration and at 10 a.m.
van der Kolk
J H
JH
Department for Large Animal Medicine and Nutrition, Veterinary Faculty, University of Utrecht, The Netherlands.
Breukink
H J
HJ
Wensing
T
T
Mol
J A
JA
D000302:Adrenal Cortex / Q000502:physiology*; D000304:Adrenal Cortex Function Tests / Q000662:veterinary*; D000324:Adrenocorticotropic Hormone / Q000009:adverse effects / Q000138:chemical synthesis; D000818:Animals; D002417:Cattle / Q000502:physiology*; D005260:Female; D006854:Hydrocortisone / Q000097:blood; D007774:Lactation; D008321:Mammary Glands, Animal / Q000187:drug effects / Q000378:metabolism; D008892:Milk / Q000378:metabolism*
D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone