Induced parturition in cattle. II. Plasma oestrogen and progesterone levels.

Plasma oestrogen and progesterone levels were determined in cattle at the time of dexamethasone induced parturition. Oestrogen levels were elevated from the day after dexamethasone administration as well as on the day of parturition but declined rapidly to low levels on the day following parturition. Progesterone levels showed a decrease from the day of dexamethasone administration until parturition with a rapid drop to very low levels on the day following calving. These results are similar to those reported by other workers.