PLASMA LEVELS OF ANDROSTENEDIONE, EPITESTOSTERONE, TESTOSTERONE AND OESTROGENS IN COWS AT PARTURITION

Abstract

The concentration of total unconjugated oestrogens in the peripheral plasma of cows increased from 2·00±0·20 (s.e.m.) ng/ml 7 days before to 3·87±0·50 ng/ml 1 day before parturition and declined to values below 0·30 ng/ml on day 2 post partum. The concentrations of androstenedione, epitestosterone and testosterone remained approximately constant at 0·90±0·10,0·92±0·08 and 0·40±0·20 ng/ml respectively during the last week of pregnancy. After parturition the concentration of the three androgens declined rapidly. Similar to data obtained in goats we did not find a marked increase in androgen levels in the peripheral blood of cows before parturition.