Pregnancy in the domestic cat after vaginal or transcervical insemination with fresh and frozen semen

The objective was to compare pregnancy rates in domestic cats using fresh semen for intravaginal artificial insemination (IVI), either at the time of hCG treatment for induction of ovulation, or 28 h later, and to compare pregnancy rates following IVI or transcervical intrauterine insemination (IUI) of frozen–thawed semen. Eighteen queens were inseminated during 39 estrus cycles. Fresh semen with 13.5 ± 5.4 × 106 sperm (range, 6.8–22 × 106) collected by electroejaculation from four male cats was used in Experiment 1, and cryopreserved semen (20 × 106 sperm, with 70 ± 5% post-thaw motility) from one male cat was used in Experiment 2. Serum concentrations of estradiol-17β and progesterone were determined in most queens on the day of AI and again 30–40 days later. Treatment with 100 IU of hCG 3 days after the onset of estrus induced ovulation in 95% of treated queens. Pregnancy rates to IVI with fresh semen at the time of hCG administration versus 28 h later were not different (P = 0.58); overall 33% (5/15) of the queens became pregnant. For frozen–thawed semen, AI was consistently done 28 h after hCG administration; IUI and IVI resulted in pregnancy rates of 41.7% (5/12), whereas no queen (0/12) became pregnant by IVI (P = 0.0083). In conclusion, an acceptable pregnancy rate was obtained with frozen–thawed semen in the domestic cat by non-surgical transcervical IUI; this method might also be useful in other small felids.