RECENT ATTEMPTS TO IMPROVE THE FERTILITY OF FROZEN RAM SEMEN INSEMINATED INTO THE CERVIX

Methods for the frozen storage of ram semen were first developed in th e 1960s and 1970s, but low levels of fertility were achieved when froz en-thawed semen was deposited into the cervix. High fertility can, how ever, be obtained after deposition of frozen semen directly into the u terus, and the development of the laparoscopic method of uterine insem ination led to an increase in the use of frozen semen during the 1980s . The cost and complexity of laparoscopy creates a need for improvemen ts in the fertility of frozen semen using simpler insemination methods . Progress in recent research aimed at improvement of both the surviva l of frozen spermatozoa and the method of cervical insemination are pr esented. The potential of a recently developed method of transcervical insemination is also discussed.