The tufted deer is a small deer, listed as near threatened on the IUCN Red List, and there is no information on the fundamental reproductive biology of this species. In this study, we report for the first-time, characterization of male reproductive traits and cryopreservation of semen in this species. Males were subjected to electroejaculation during each season (autumn, winter, spring, and summer), and ejaculates were assessed for motility and quality traits. Fecal samples were collected 3 - 5 times weekly for 2 years and analyzed for androgen metabolites using enzyme immunoassay. Ejaculates with >70% motility were cryopreserved using Beltsville extender (BF5F) or Triladyl®. Straws were thawed and assessed subjectively as well as swim-up processed to isolate motile spermatozoa for CASA analysis and acrosome integrity at hourly interval. Tufted deer male reproductive and semen traits peaked in autumn. Mean fecal androgen concentrations were highest in the summer compared to baseline values during rest of the year. Sperm motility and acrosome integrity were lower immediately after thawing in both cryodiluents compared with raw ejaculates. Motility characteristics following swim-up were higher in BF5F compared with Triladyl. Four hour after thawing, both percent sperm motility and progression declined further and were similar between BF5F and Triladyl. However, the proportion of spermatozoa with intact acrosomal membranes was higher in BF5F than Triladyl. Results indicate that tufted deer exhibit seasonal variations in reproductive traits and that BF5F better preserves sperm motility and acrosomal integrity after cryopreservation compared with Triladyl.
