EFFECTS OF EQUINE CHORIONIC-GONADOTROPIN, HUMAN CHORIONIC-GONADOTROPIN, AND LAPAROSCOPIC ARTIFICIAL-INSEMINATION ON EMBRYO, ENDOCRINE, AND LUTEAL CHARACTERISTICS IN THE DOMESTIC CAT

The effects of gonadotropin treatment and laparoscopic artificial inse mination (Al) on embryo quality, serum progesterone and estradiol conc entrations, and luteal progesterone content were examined in the domes tic cat. These data were compared to similar historical data reported for naturally estrual, mated queens. All queens in this study (n = 32) were treated with eCG followed by 1) natural breeding (eCG-NB), 2) NE and hCG (eCG-NB-hCG), 3) NE and a sham Al procedure (eCG-NB-sham Al), or 4) hCG and actual Al (eCG-hCG-AI). Queens ovulating in response to treatment were ovariohysterectomized, and oviducts and uteri were flu shed to collect embryos. Ovarian structures were recorded, corpora lut ea (CL) were excised and evaluated for progesterone content, and serum was analyzed for estradiol-17 beta and progesterone. Follicle and CL numbers ranged from 0 to 28 and 2 to 42 per cat, respectively, and tre atment means did not differ (p greater than or equal to 0.05) among gr oups. Embryos were recovered from oviducts and uterine horns in all tr eatment groups, and recovery ranged from 60-96%. Mean embryo number pe r queen ranged from 8.2 +/- 2.6 to 23.2 +/- 3.8 and did not differ (p greater than or equal to 0.05) among groups. However, the proportions of unfertilized oocytes were greater (p < 0.05) for groups treated wit h hCG and/or artificially inseminated, and the proportion of blastocys ts produced (31 of 107, 29.0%) was lower (p < 0.05) in the eCG-hCG-AI group than for any other treatment (range, 59 of 116 [50.9%] to 67 of 116 [57.8%]). Not all queens in each group produced good-quality embry os (eCG-NB, 5 of 5; eCG-NB-hCG, 5 of 8; eCG-NB-sham Al, 2 of 5; and eC G-hCG-AI, 3 of 6). Serum progesterone and estradiol-17 beta, and total luteal progesterone per ovary did not differ (p greater than or equal to 0.05) among treatments. Compared to historical controls (naturally estrual, mated queens), eCG-NB queens produced > 4 times as many good -quality embryos and blastocysts. Similarly, eCG-hCG-AI-treated queens produced > 4 times the number of oocytes and embryos, although a high proportion of these were poor quality and did not develop to blastocy sts. Together, these results indicate that queens treated with eCG are capable of consistently producing many good-quality embryos, at least half of which develop to blastocysts in culture. These data support t he use of eCG in felids and suggest that other factors are responsible for reduced pregnancy success and small litter sizes following assist ed reproduction.