Hysteroscopic observation of cervical response in the oestrous and anoestrous ewe

Extract

Due to the interlocking nature of the ovine cervix semen deposition during cervical insemination takes place at the external cervical os resulting in commercially unacceptable conception rates when using frozen/thawed semen. During natural mating it is not known whether the cervix plays a pro-active role in the transport of semen into the uterine lumen. Endogenous and seminal prostaglandins and coitally-released oxytocin may contribute to the stimulation of the cervix and enhance the capture and movement of semen through the cervical canal. Electromyographical studies showed spontaneous motility of the ovine cervix and uterus with the greatest activity recorded during the periovulatory period (Garcia-Villar et al., 1982). Recent advances in fibre-optics and video technology allowed us to make direct observations and time-sequence recordings of cervical activity in fully conscious ewes under minimal restraint. The aim of the study was to observe and record for the first time the response of the external os cervix before and immediately after ram stimulation both with and without intromission, during artificial deposition of semen and after administration of exogenous oxytocin.