Comparison of fertility data from vaginal vs intrauterine insemination of frozen-thawed dog semen: a retrospective study

摘要

274 bitches were inseminated directly into the uterus using transcervical catheterization with the Norwegian catheter (NIU, 167 AI), a fiberoptic endoscope (EIU, 19 AI), or in the cranial vagina (VAG, 141 AI), during 1993-95 at the Cryogenetic Laboratories, Pennsylvania, USA and at the Department of Obstetrics and Gynaecology, Swedish University of Agricultural Sciences, Uppsala, Sweden. Semen from 185 males of 76 breeds were used. Whelping rates >70% were obtained when post-thaw sperm motility was>=40%. Whelping rates were 84.4, 58.9 and 57.9% (P<0.001) for NIU, VAG and EIU respectively. Increasing the number of VAG to 2 increased (P<0.05) the whelping rate. The mean interval from the first AI to whelping was 61.8±2.4 days, and was longer (P<0.001) for VAG (62.7±2.7 days) than for NIU (61.2±2.1 days). The mean interval from the last AI to whelping was 60.1±1.9 days, and was similar in VAG (60.2 ±2.2 days) and NIU (60.0±1.6 days). Pregnancy duration was not affected by breed or litter size. 1158pups were born from 327 inseminations. The litter size was 5.4±3.0, 4.0±2.7 and 6.0±2.1 (P<0.001) for NIU, VAG and EIU respectively. Litter size was also affected by breed (P = 0.006), and for VAG, by the number of inseminations per cycle (P = 0.009). Itis concluded that good cryopreservation and non-surgical intrauterine AI with the Norwegian catheter can result in whelping rates and litter sizes similar to those from natural mating. This is thought to be the first study to show that intrauterine deposition of frozen-thawed dog semen results in a significantly higher whelping rate and larger litter size than vaginal deposition.