Effect of Date Palm Pollen Extract Supplementation on Ram Epididymal Sperm Quality during Chilled Storage

Post-mortem recovery of epididymal spermatozoa is a valuable technique for genetic conservation in sheep, but is limited by sperm vulnerability to oxidative damage during chilled storage. This study evaluated the protective effects of date palm pollen extract (DPPE) on ovine epididymal sperm quality stored in protein-free saline at 4°C.Epididymal sperm were collected from five mature rams (n=5).For each ram, samples were divided into three aliquots and diluted to a final concentration of 350 × 106 cells mL-1 with DPPE at 0 (control), 40, or 80 mg mL-1.Sperm total motility, progressive motility, and plasma membrane integrity were assessed at 0, 24, and 48 h using computer-assisted sperm analysis (CASA) and hypo-osmotic swelling (HOS) tests. Over 48 hours, all parameters declined significantly (p<0.05), but DPPE attenuated this decline in a dose-dependent manner. The 80 mg mL-1 concentration provided best protection, maintaining higher total motility (67.5% vs.58.3% control), progressive motility (54.7% vs.45.5% control), and membrane integrity (63.9% vs.55.1% control) at 48 hours (p<0.05). These protective effects likely reflect DPPE’s flavonoid and phenolic content, which scavenge reactive oxygen species. Validation in commercial, protein-containing extenders and assessment of in vivo fertility are required before field application.