Laparoscopic Oviductal Artificial Insemination Improves Pregnancy Success inExogenous Gonadotropin-Treated Domestic Cats as a Model for Endangered Felids

摘要

Artificial insemination (AI) in cats traditionally uses equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG) to induce follicular development and ovulation, with subsequent bilateral laparoscopic intrauterine insemination. However, long-acting hCG generates undesirable secondary ovulations in cats. Uterine AI also requires relatively high numbers of spermatozoa for fertilization (∼8 × 10⁶ sperm), and unfortunately, sperm recovery from felids is frequently poor. Using short-acting porcine luteinizing hormone (pLH) instead of hCG, and using the oviduct as the site of sperm deposition, could improve fertilization success while requiring fewer spermatozoa. Our objectives were to compare pregnancy and fertilization success between 1) uterine and oviductal inseminations and 2) eCG/hCG and eCG/pLH regimens in domestic cats. Sixteen females received either eCG (100 IU)/hCG (75 IU) or eCG (100 IU)/pLH (1000 IU). All females ovulated and were inseminated in one uterine horn and the contralateral oviduct using fresh semen (1 × 10⁶ motile sperm/site) from a different male for each site. Pregnant females (11/16; 69%) were spayed approximately 20 days post-AI, and fetal paternity was genetically determined. The number of corpora lutea (CL) at AI was similar between hormone regimens, but hCG increased the number of CL at 20 days post-AI. Numbers of pregnancies and normal fetuses were similar between regimens. Implantationabnormalities were observed in the hCG group only. Finally, oviductal AI produced morefetuses than uterine AI. In summary, laparoscopic oviductal AI with low sperm numbers ineCG/hCG- or eCG/pLH-treated females resulted in high pregnancy and fertilizationpercentages in domestic cats. Our subsequent successes with oviductal AI ineCG/pLH-treated nondomestic felids to produce healthy offspring supports cross-speciesapplicability.