Post-thawing effects of three cryopreservation diluents on Rusa deer (Rusa timorensis) spermatozoa

The aim of this study was to evaluate home-made and commercial extenders for the cryopreservation of Rusa deer semen. After collection by electroejaculation, six ejaculates were diluted and frozen in TES-based, Tris-based and Triladyl® extenders. Subjective motility, viability, morphology, acrosome integrity and membrane functionality were assessed post-thawing and after 1-hr incubation at 37°C (Thermal stress test). Total and progressive motility, and kinematic parameters were also assessed through CASA system. Post-thawing sperm progressive motility (PM), velocity according to the straight path (VSL) and linearity (LIN) showed significant differences, and higher values were detected for spermatozoa diluted with Triladyl® and TES (p < 0.05) as compared with Tris (PM of Triladyl® 14.7% vs. 3.2% TES and 2.5% Tris; VSL 56 for Triladyl® , 59.2 for TES and 41.7 for Tris; LIN 45.6 for Triladyl® , 52 for TES and 36.5 for Tris). Triladyl® and TES extender led to better post-thawing sperm parameters, but these preliminary results need to be verified through artificial insemination trials.