Bovine plasma corticoids during parturition.
Concentrations of adrenal corticoids in plasma were determined by a competitive protein-binding technique using jugular blood samples taken three times daily and more frequently during labor from 21 cows before and after parturition. The prepartum value was 6 ng/ml with a sharp rise during the last 16 h before calving. The average value at the time of calving was 19.2 ng/ml with a significant drop 1 h after calving to 11.2 ng/ml and a return to basal concentrations by 3 days postpartum. Evidence that labor is responsible for the increased corticoid is given. Maternal cortisol at calving was correlated with the time taken to calve .23, calf cortisol .04, cow:calf weight ratio -.07, and calf weight .14.
D000818:Animals; D002417:Cattle / Q000502:physiology*; D005260:Female; D006854:Hydrocortisone / Q000097:blood*; D007774:Lactation; D011247:Pregnancy; D011270:Pregnancy, Animal; D013997:Time Factors
D006854:Hydrocortisone