The effect of seminal plasma on the quality of coated ram frozen-thawed spermatozoa

Two experiments were designed to examine the effects of crude seminal plasma (CSP) exposure of ejaculated and epididymal spermatozoa before freezing. Experiment 1، two consecutive ejaculates were collected (n=4) within 5 min، the second one was carried out in a tube containing Fiser extender (coated spermatozoa); by centrifugation، seminal plasma was removed from coated ejaculates. The pellets were split into three parts and 0، 50 and 100% CSP (v/v) was added and they were frozen. Samples were thawed and incubated at 37°C for 6 h. The highest progressive motility (10. 41%) and the highest hypo-osmotic responses (12. 62%) were found for the coated spermatozoa without CSP at 6 (P<0. 05). The maximum viability was found for coated spermatozoa without CSP at 0 (29. 4%) and 6 (17%، P<0. 05). Experiment 2، epididymal spermatozoa were recovered (n=6)، pooled and split into three fractions and 0، 50 and 100% CSP and the diluents were added، after that they were frozen. Thawed epididymal spermatozoa were incubated at 37°C for 6 h. The highest (33. 3%) and lowest (25%) progressive motility were found for the epididymal spermatozoa without CSP and the epididymal spermatozoa with 100% CSP at 0، respectively (P<0. 05). The highest (19. 37%) and the lowest (9. 38%) viability were related to the epididymal spermatozoa with 0 and 100% CSP at 6، respectively (P<0. 05). Under the conditions of the current study، the addition of CSP to the ram epididymal and coated spermatozoa strengthened the detrimental effect of the freezing procedure.