Responsiveness of ovaries to exogenous gonadotrophins and laparoscopic artificial insemination with frozen-thawed spermatozoa in ocelots (Felis pardalis).

Abstract

Adult female ocelots (Felis pardalis) were treated with one of four dosages of equine chorionic gonadotrophin (eCG) and human chorionic gonadotrophin (hCG) (100 iu eCG/75 iu hCG, n = 3; 200 iu eCG/150 iu hCG, n = 4; 400 iu eCG/150 iu hCG, n = 5; 500 iu eCG/225 iu hCG, n = 5); hCG was administered 80 h after eCG. Ovaries of each animal were evaluated by laparoscopy 39-43 h after hCG, and blood was collected for progesterone and oestradiol analysis. With progressive increases in gonadotrophin dosage, female ocelots produced more (P < 0.05) unovulated follicles (> or = 2 mm in diameter), ranging from 1.3 +/- 0.7 (mean +/- SEM) follicles per female at the lowest dosage to 8.8 +/- 2.8 follicles per female at the highest dosage. Similarly, ocelots produced more (P < 0.05) corpora lutea with increasing gonadotrophin dosages, with mean values ranging from 0-5.0 +/- 1.2 corpora lutea. However, across treatment groups, a similar proportion (P > 0.05) of females ovulated in response to each dosage. At laparoscopy, serum concentrations of oestradiol (overall mean, 330.2 +/- 62.2 pg ml-1) and serum concentrations of progesterone (overall mean, 18.5 +/- 6.4 ng ml-1) in ovulating females did not differ (P > 0.05) across treatment groups. Ten ovulating ocelots were laparoscopically inseminated with fresh (4.7 +/- 0.2 x 10(6); n = 2 females) or frozen-thawed (10.7 +/- 1.8 x 10(6); n = 8 females), motile spermatozoa. One female treated with 500 iu eCG/225 iu hCG and inseminated with 7.5 x 10(6) motile, frozen-thawed spermatozoa conceived and gave birth to a healthy male kitten after a gestation of 78 days. We conclude that ocelots are relatively insensitive to exogenous gonadotrophins, requiring much higher dosages (on a per body mass basis) to elicit an appropriate ovarian response than do any other felid species studied to date. Nonetheless, the gonadotrophin-treated female can become pregnant and carry offspring to term after laparoscopic intrauterine insemination with frozen-thawed spermatozoa.