Transcervical artificial insemination in sheep: effects of a new transcervical artificial insemination instrument and traversing the cervix on pregnancy and lambing rates

Cervical anatomy limits the use of transcervical intrauterine artificial insemination (TC AI) in sheep. We have developed an instrument to cope atraumatically with the cervix; although this instrument has not affected fertilization rate or pregnancy rate through Day 3, the effects on sperm transport and pregnancy after Day 3 are not known. The objective of the present study was to determine whether our TC AI instrument affected sperm transport, pregnancy rates, or lambing rate. In Experiment 1, ewes were assigned to two treatments: TC AI using the new TC AI instrument ( n=10) or AI via laparotomy using a laparoscopic AI instrument ( n=10). Twenty hours after artificial insemination, the uterine horns and oviducts were recovered and flushed to collect spermatozoa. Sperm transport did not differ ( P>0.05) between the two treatments. In Experiment 2, ewes were assigned to three treatments: TC AI using the new TC AI instrument+sham intrauterine AI via laparotomy ( n=29); sham TC AI+intrauterine AI via laparotomy using a laparoscopic AI instrument ( n=29); and sham TC AI+intrauterine AI via laparotomy using the new TC AI instrument ( n=30). On Day 14 after AI, uteri were collected and flushed to recover blastocysts. Transcervical deposition of semen reduced ( P