Platelet activating factor improves the in vitro penetration of zona free hamster eggs by buffalo (Bubalus bubalis) spermatozoa

Twelve buffalo bulls of Murrah breed, selected on the basis of their conception rates, were classified into low-, moderate- and high-fertility groups. Frozen semen was thawed and treated with 200 μM platelet activating factor (PAF) for 15 min at 37 °C and 5% CO2. In both treated and control (no PAF) semen samples (five replicates per bull), the following were assessed: motility, acrosome reaction (AR) evaluation (for 10 replicates of each bull), and zona-free hamster oocyte penetration test-to determine aspects of fertilization in vitro, viz., sperm attached per ovum (SA/O), fertilization percent (FP), fertilization index (FI), and polyspermic ova (PO). There was an effect of group (P < 0.01) on all parameters; all except motility were increased by PAF treatment. However, the group X treatment interaction was not significant for any parameter. The overall mean values of motility, AR, SA/O, FP, FI, and PO, for controls, treated spermatozoa and (net change) were: 42.89 ± 0.85, 36.65 ± 0.85, (−6.24); 28.94 ± 0.46, 61.44 ± 0.58, (32.50); 126 ± 2, 145 ± 2, (19); 74.21 ± 1.59, 89.11 ± 1.18, (14.90); 0.79 ± 0.02, 1.10 ± 0.03, (0.31) and 5.22 ± 1.22, 21.69 ± 1.88, (16.47)%, respectively. In conclusion, PAF significantly increased the AR and other aspects of fertilization, despite a small reduction in motility.