Radioimmunoassay of androstenedione and testosterone in cow plasma at the time of luteolysis and oestrus

Abstract

Androstenedione and testosterone were measured by radioimmunoassay after chromatography on micro columns of Lipidex 5000 in jugular plasma samples taken every 2-3 h at the time of luteolysis and oestrus in 3 dairy cows. The concentrations of androstenedione and testosterone varied between 5 and 60 pg/ml and 5 and 80 pg/ml respectively and no consistent pattern in the fluctuations of either steroid was observed.