Influence of storage period on motion characteristics of frozen-thawed Awassi ram spermatozoa

Abstract

The motion characteristics of Awassi ram semen, cryopreserved in 0.25 ml straws, Were studied after 8, 16 or 24 months of storage by computer-assisted semen analysis technique. Ejaculates of good quality were extended @ 1 000 million spermatozoa/ ml and frozen @ -250°C / min in a cell freezer. Frozen straws were plunged in liquid nitrogen and thawed at 50° C for 10 sec in a water bath. The mean post-thaw recovery of motile spermatozoa was >70% at the 3 storage periods varying from 72.0 to 74.7%. Storage had significant effect on per cent medium but had no significant effect on per cent motility, per cent rapid, per cent slow, per cent linearity, per cent straightness, curvilinear velocity, average path velocity, straight line velocity, beat frequency and amplitude of lateral head displacement of spermatozoa. Post-thaw viability of ram spermatozoa remained unaltered during long-term preservation in mini-straws.