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

The motion characteristics of Awassi ram semen, cryopreserved in 0.25 mi st raws, 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 @ -25 degrees C / min in a cell freeze r, Frozen straws were plunged in liquid nitrogen and thawed at 50 degrees C for 10 sec in a water bath. The mean post-thaw recovery of motile spermato zoa was >70% at the 3 storage periods varying from 72.0 to 74.7%. Storage h ad significant effect on per cent medium but had no significant effect on p er cent motility, per cent rapid, per cent slow, per cent linearity, per ce nt straightness, curvilinear velocity, average path velocity, straight line velocity, beat frequency and amplitude of lateral head displacement of spe rmatozoa. Post-thaw viability of ram spermatozoa remained unaltered during long-term preservation in mini-straws.