Novel Low-Voltage Electro-Ejaculation Approach for Sperm Collection from Zoo Captive Lanyu Miniature Pigs (Sus barbatus sumatranus)

SIMPLE SUMMARY: Preservation of genetic materials from zoo animals is important to improve genetic diversity and to prolong the existence of endangered species for future retrieval. Methods to acquire sperm samples from the animals can be achieved by hand penile massage or by rectal stimulation with electric probe. Traditional electrical stimulation applies relatively high voltage to achieve sufficient stimulation; however, this method causes stress and discomfort to the animal. In the current study, we establish a low-voltage base electrical stimulation approach to obtain semen sample from zoo captive lanyu miniature pigs. We showed that, with our method, a sufficient amount of semen ejaculates with good sperm quality can be obtained. Future improvement on cryopreservation protocol will allow better preservation outcome for successful fertilization in this species. ABSTRACT: Semen collection can be achieved via hand penile massage or rectal stimulation using electro-ejaculation methods. Traditional electro-ejaculation procedure applied relatively high voltage of 3–15 volts with a maximum current of 900 mA. However, these manipulations often result in great stress and discomforts in animals. In this study, we showed low-voltage electro-ejaculation procedure using 2–3 volts with a maximum current of 500 mA can efficiently stimulated ejaculations in zoo captive lanyu miniature pigs with a high success rate of 81.3% (13/16). Besides normal semen properties (semen volume, pH, sperm concentration), we demonstrated that low-voltage electro-ejaculation caused less stress in the animals, and sperm cells obtained via low-voltage electro-ejaculation exhibit low abnormality (10.3%), high viability (84.3%), motility (75.7%), progressive motility (63.7%), and acrosome integrity (88%). However, cryopreservation protocol used in the current study requires further optimization, as sperm mitochondrial function was partially compromised during freezing procedures. Taken together, we demonstrated in this study that a low-voltage electro-ejaculation approach can be used to obtain quality sperm cells from zoo captive lanyu miniature pig with less physical stress during electro-ejaculation procedure.