Viability longevity and quality of epididymal sperm stored in the liquid state of European red deer (Cervus elaphus elaphus).

The aim of the study was to evaluate viability longevity and quality of liquid-stored epididymal sperm of European red deer (Cervus elaphus elaphus). Sperm samples were recovered from epididymides of 15 mature stags. Samples were diluted to 100 × 10 sperm⁄mL in modified Salomon's extender and stored at 5 °C for 25 days. Sperm were analyzed to determine total motility (TMOT), progressive motility (PMOT) and motion variables [CASA system], acrosomes with normal apical ridges (NAR), viability and acrosomal status (FITC-PNA/PI), plasma membrane integrity (PMI) and mitochondrial membrane potential (MMP) on the first day (D1) and every other day of storage (D3-D25). Data were analyzed using a one-way analysis of variance (ANOVA). Spermatozoa remained motile until D25, whereas TMOT exceeded 60%, NAR and PMI exceeded 80%, FITC-PNA/PI exceeded 75%, and MMP approximated 70% until D11. There was a lesser (P < 0.05) value for these variables on D5 (relative to D1). Furthermore, there was a decrease in values for motility variables as duration of storage increased, excluding amplitude of lateral head displacement, on D3. The results indicate that liquid-stored epididymal sperm of European red deer are characterized as having a long viability (25 days) with a retention of sperm quality for as long as 11 days in the liquid storage state. In vitro or in vivo studies, however, are required to confirm the findings in the present study.