Comparison of efficiency between two artificial insemination methods using frozen-thawed semen in domestic cat (Felis catus) : Artificial insemination in domestic cats

The aim of this study was to compare the efficiency of the intravaginal (IVAI) vs. intrauterine artificial insemination (IUAI) using frozen-thawed sperm in the domestic cat. Semen was collected from two tom cats using an artificial vagina and samples were assessed for motility (computer-assisted sperm analysis (CASA)), sperm morphology and plasma membrane integrity. After dilution with TRIS/OEP/YOLK (4% of glycerol), sperm samples were loaded into 0.25mL straws (25x10⁶ motile sperm/straw), incubated at 5°C for 20min and cryopreserved over liquid nitrogen (LN₂) vapor for 15min and then immersed in LN₂. For each AI, four straws from the same male were thawed (12s at 46°C) and centrifuged at 250x g for 8min to pellet the sperm. The supernatant was discarded and sperm pellet resuspended with the remaining liquid, approximately 100μL, and analyzed as described above. Queens were treated with a single im injection of 100IU eCG to induce ovarian follicular development. Final oocyte maturation and ovulation was induced with 100IU hCG given im at 82-84h after eCG administration. Thirty hours after hCG administration, females were inseminated either intrauterine (n =8 queens) or intravaginally (n =8 queens), using thawed sperm from a single male. Although a pronounced decrease in sperm motility, acrosome and plasma membrane integrity was observed in sperm samples from both cats, a pregnancy rate of 75% was achieved when using the intrauterine AI method compared with 0% pregnancy when inseminated intravaginally.