Semen from 4 Holstein bulls was diluted in 4 different extenders, filt
ered with Sephadex ion-exchange column, and frozen in liquid nitrogen.
Sperm motility, progressive motility, path velocity, progressive velo
city and the percentage of normal acrosomes of filtered and nonfiltere
d semen were recorded before and after freezing. Semen characteristics
were significantly influenced by extender, filtration and freezing. B
efore and after freezing, motility measurements and the percentage of
normal acrosomes were higher (P<0.001) in filtered than in nonfiltered
spermatozoa. Post-thaw recovery rate of:motile spermatozoa was higher
in filtered semen than nonfiltered (68 vs 39%, P<0.0001). The reducti
on in motility, progressive motility and the percentage of normal acro
somes during freezing and thawing processes were significantly lower (
P<0.0001) in filtered semen (34, 34 and 4%, respectively) than nonfilt
ered (59, 54 and 15%, respectively). Post-thaw viability of spermatozo
a was significantly affected by extender, filtration and time (P<0.000
1). Immediate (0 h) post-thaw motility of nonfiltered semen (29%) was
similar to 4-h post-thaw motility of filtered semen (25%; P>0.05). In
conclusion, bull spermatozoa recovered by Sephadex ion-exchange filtra
tion showed better post-thaw viability.