3 APPLICATION OF LAPAROSCOPIC OVIDUCTAL ARTIFICIAL INSEMINATION FOR CONSERVATION MANAGEMENT OF BRAZILIAN OCELOTS AND AMUR TIGERS

Abstract

The Brazilian ocelot (Leopardus pardalis mitis) and Amur tiger (Panthera tigris altaica) are 2 iconic cat species that are becoming increasingly imperiled in the wild. Although both felids are managed in North American zoos by species survival plans (SSP), their long-term sustainability has proven difficult through captive breeding alone, necessitating the development and application of assisted reproductive techniques. Our recent progress using laparoscopic oviducal artificial insemination (LO-AI) in domestic cats (Conforti et al. 2013 Biol. Reprod. 89, 1–9) suggested that this approach could help improve reproductive management of nondomestic felids. In this study, our objectives were to (1) assess ovarian and endocrine responses to 2 exogenous gonadotropin regimens in ocelots and Amur tigers, and (2) investigate fertility and offspring production following LO-AI with freshly collected and/or frozen–thawed semen in both felid species. Female ocelots (n = 13) and Amur tigers (n = 10), housed at 16 North American zoos and recommended for breeding by the Ocelot and Tiger SSP, were treated with 2 different eCG/porcine LH (pLH) regimens (400 or 600 IU of eCG, 3000 IU of pLH, ocelots; 750 or 1000 IU of eCG, 10 000 IU of pLH, tigers). Ovarian responses were evaluated laparoscopically at 39 to 45 h post-pLH, and ovulatory females were inseminated using low numbers of freshly collected or frozen–thawed spermatozoa (≤5 million motile sperm/oviduct). Serially collected fecal samples from each female were lyophilized, extracted, and assessed via enzyme immunoassay for oestrogen and progesterone metabolite profiles. Most ocelots (11/13, 85%) and tigers (7/10, 70%) ovulated following gonadotropin treatment, with no difference (P > 0.05) between eCG dosages in mean (± s.e.m.) follicle or corpus luteum (CL) number in ocelots (11.5 ± 4.2 follicles, 2.8 ± 1.0 CL, 400 IU of eCG; 9.9 ± 5.2 follicles, 3.1 ± 1.3 CL, 600 IU of eCG) or tigers (9.0 ± 4.6 follicles, 4.0 ± 2.8 CL, 750 IU of eCG; 12.7 ± 4.4 follicles, 6.0 ± 1.7 CL, 1000 IU of eCG). Similarly, peak fecal hormone concentrations did not differ (P > 0.05) between regimens, except for slightly greater (P ≤ 0.05) progesterone levels for 10 days post-treatment with the higher eCG dose in tigers. Independent t-tests were used for all statistical calculations. One Brazilian ocelot and 1 Amur tiger conceived following LO-AI with freshly collected semen (10 × 10⁶ motile sperm, ocelot; 0.15 × 10⁶ motile sperm, tiger), with each producing 1 viable offspring after an 83-day and 103-day gestation, respectively. These births represent the second ocelot and first tiger produced by LO-AI. Our findings indicate that high and low eCG dosages may be equivalent and that viable offspring can be produced following LO-AI with relatively low sperm numbers in both species. Further refinement of ovarian synchronization and semen cryopreservation methods may be necessary for LO-AI to be applied routinely for ocelot and tiger conservation efforts.

Funded by the Institute of Museum and Library Services, Riverbanks Zoo & Garden and Minnesota Zoo; with thanks to Ocelot & Tiger SSP, and participating zoos).