[Demonstration and evolution of chorionic gonadotropin in ewes].

Occurrence of ovine Chorionic Gonadotropin (oCG) is demonstrated in placenta and amniotic fluid with the use of a radioreceptor assay (corpus luteum membranes) in ewes. Identification of oCG is possible as early as 15th day of pregnancy. It should be secreted at a constant rate, and its maximum concentration is recorded on the 130th day. This hormonal factor might be one of the major components accountable for high progesteronemia observed during the 100 last days of pregnancy.