Impact of mimicking natural dispersion on breeding success of captive North American Cheetahs (Acinonyx jubatus).

This paper examines the effects of transfer away from natal facility and littermate presence on cheetah breeding success in the AZA Species Survival Plan (SSP) population. Transfer and breeding history data for captive males and females were gathered from seven and four AZA SSP breeding facilities, respectively, to identify factors influencing breeding success. The results indicate that transfer history (p = 0.032), age at transfer (p = 0.013), and female littermate presence/absence (p = 0.04) was associated with breeding success, with females transferred away from their natal facility before sexual maturity and without littermates present accounting for the highest breeding success. Keeping males at their natal facility and/or removing them from their coalitions did not negatively affect their breeding success. Males appeared to demonstrate the same fecundity regardless of transfer history or coalition status, indicating that dispersal away from natal environment was not as critical for the breeding success of males compared with female cheetahs. These results highlight the significance of moving females away from their natal environment, as would occur in the wild, and separating them from their female littermates for optimization of breeding success in the ex situ population.

Enhancing captive Indian rhinoceros genetics via artificial insemination of cryopreserved sperm.

The objective of this study was to design an artificial insemination (AI) protocol using cryopreserved spermatozoa to obtain pregnancies in captive Indian rhinoceroses (Rhinoceros unicornis). Four methods developed varied by timing and approach, as follows; Method 1: females (n=2) were inseminated pre- and post-ovulation under general anesthesia, Method 2: females (n=2) were inseminated pre-ovulation without anesthetic via endoscopy, Method 3: females (n=1) were inseminated pre-ovulation without anesthetic via manual insertion of an insemination catheter, Method 4: females (n=2) were inseminated same as Method 3 with the addition of standing sedation. Semen deposition site varied as a result of changes in AI technology and experience. All females conceived following intrauterine AI using three methods. Four pregnancies (n=3 females) produced via Method 3 and 4 resulted in term births (n=2 male calves, n=2 female calves) at 481.8±12.8days post-AI. Unfortunately, two early pregnancy losses were documented in a fourth female conceiving via Method 2. Pregnancy rates were 0%, 22%, 17%, and 50% for Method 1-4, respectively. Method 3 and 4 rates improved to 29% and 67%, respectively when accounting for AI's conducted only on ovulatory estrous cycles. Spermatozoa (n=5 males) were cryopreserved 0.3-9.3 y prior to successful AI procedures. The lowest dose of frozen-thawed sperm resulting in conception was 500×10(6) motile sperm. Mean time from AI to ovulation in conceptive and non-conceptive cycles was 26±11.8h and 66±80.7h, respectively.