Cryopreservation and ensuing in vitro fertilization ability of boar spermatozoa from epididymides stored at 4degree C.

摘要

The effect of storing boar epididymides at 4鳦 for a few days on post-thaw motility and in vitro fertilization (IVF) potential of spermatozoa recovered from these epididymides was studied. 20 pairs of epididymides were recovered from Large White boars at slaughter, and spermatozoa were immediately collected from one of each pair and frozen (controls). The remaining epididymides were cooled to 4?and stored for 1, 2 or 4 days after which spermatozoa were collected and frozen (experimental groups). In control samples, sperm motility was well maintained during the dilution procedure, but declined after freezing and thawing, while in the experimental groups sperm motility decreased immediately after collection (P<0.01). IVF experiments showed that penetration rates of spermatozoa from epididymides stored for 1, 2 or 4 days (12, 13 and 2% respectively) were lower (P<0.05) than those of control samples (40%). Oocyte penetration rate ability seemed to be reflected by acrosome integrity. The motility ofspermatozoa with the ability to penetrate oocytes from the 1- and 2-day stored groups did not differ from that of controls. The motility of spermatozoa lacking penetration ability gradually decreased as storage period increased. Control and experimentalgroups had high rates of monospermic penetration (64-90%) and male pronuclear formation (67-71%).