Cryopreservation of alpaca epididymal sperm using commercial equine semen extenders: preliminary investigation

Abstract

Cryopreservation of epididymal sperm enables saving genetic material in cases of unexpected death or castration. Objective of this
preliminary study was to evaluate alpaca epididymal sperm viability and motility following cryopreservation using 3 commercially
available equine semen extenders. We hypothesized that equine semen extenders yield postthaw results comparable to those reported
for alpaca epididymal sperm cryopreservation. Epididymal sperm samples were collected from 4 adult intact male alpacas at castration.
Sperm samples were extended at a 1:1 ratio with 3 commercial equine semen extenders. Extended semen was loaded into 0.5-ml
straws and frozen in liquid nitrogen vapor. Straws were immediately thawed in a circulating 38°C water bath. Following thawing,
viability and total and progressive motility were evaluated. Postthaw viability and motility was less than what has been reported for
alpaca epididymal sperm cryopreservation. Additional research is needed to determine if poor results observed are related to the semen
extender or the freezing/thawing method used.