Establishment of semen collection technique using electroejaculator and semen cryopreservation of Javan leopard (Panthera pardus melas Cuvier, 1809)

Background and Aim: The Javan leopard (Panthera pardus melas Cuvier, 1809) is a subspecies of Panthera pardus spp.,
spread across the African and Asian regions. Information on reproductive aspects is crucial for wild animals, including the Javan leopard. In this study, we aimed to develop electroejaculator (EE) techniques and evaluate cryopreservation success in Javan leopard semen.

Materials and Methods: The semen of four adult Javan leopards was collected once a week using EE. Placement of
the EE probe in the rectum was performed after ultrasound imaging (ultrasonography) to determine the prostate body
location. The semen obtained was then evaluated macroscopically and microscopically. Three Javan leopards were used for cryopreservation. The ejaculate was divided into two parts [i.e., one part diluted with AndroMed® (Minitüb, Tiefenbach, Germany) and the other part with Steridyl® (Minitüb)] at a 1:1 ratio immediately after collection and evaluation. The semen was then packed in a 0.25 mL MiniStraw® (Minitüb) then equilibrated at 4°C for 2 h. After equilibration, the straw was then frozen in liquid nitrogen vapor. Frozen semen was then stored in containers until further evaluation.

Results: The results showed that ejaculation response occurred at all levels of stimulation, while erections did not always occur. The fastest ejaculation and erection occurred at the fourth voltage. The macroscopic evaluation showed that the semen volume was 0.80±0.26 mL, cloudy white, pH 7.44±0.14, and with watery semen consistency. The microscopic evaluation showed that the sperm motility was 66.98±0.39%, with sperm viability of 75.6±1.79%. Sperm concentration was 62.17±46.95×106 mL−1 with a total concentration of 42.14±23.51×106 cells. Normal sperm morphology is only 40.72±6.26%.

Conclusion: This study concluded that the development of a semen collection technique using an EE preceded by imaging
of the EE probe location using ultrasound was effective for the ejaculation of Javan leopards. The characteristics of the semen of the Javan leopard showed moderate semen volume, sperm motility, and viability. Javan leopard showed low sperm concentration and normal sperm morphology.