Effect of oviduct and follicular fluids on ram sperm capacitation and acrosome reaction in vitro

The present study was designed to study the influence of different concentrations of oviduct fluid (OF) and follicular fluid (FF) on ram sperm capacitation and acrosome reaction in vitro. Forty semen samples were collected from three Barki rams throughout the period of study (10 weeks). Fresh semen was evaluated, layered under S-TALP (sperm Tyrode’s albumin lactate pyruvate) medium and subjected to swim up techniques. Split fractions of semen were incubated in media enriched with different levels of OF (10, 20, 40, 50 and 75 µL/mL) or FF (10, 20, 40, 50, 100, 150 and 200 µL/mL). Best concentrations were compared and used to evaluate the ram sperm functions including progressive motility, hyperactivity and acrosome reaction. The present findings showed a significant increase in individual motility percentage (IM %) when ram spermatozoa were treated with 10 and 50 µL of oviduct fluids as compared to the other treatments after 1 h of incubation. Addition of 50 µL/mL of OF or FF had beneficial effect on sperm hyperactivity after 2 and 1 h incubation respectively. Furthermore, addition of 50 µL/mL oviduct fluid to ram sperm maintained significantly (P < .05) higher total acrosome reaction (AR %) after 3 h of incubations than those observed in other groups. In conclusion, treatment of ram spermatozoa with 50 µL/mL of OF or 40 µL/mL of FF for 3–4 h incubation respectively was considered the best level of oviduct or follicular fluid to be used for IVF.