Comparison of Ovine Spermatozoal Morphological Features After Staining of Fixation and Assessment of Morphological Abnormalities in Dead/Live Spermatozoa

The objectives of this study were to (i) compare the effects of two staining techniques and one fixative solution on the morphological features of ram spermatozoa and (ii) evaluate the morphological features of dead/live spermatozoa by using EosinNigrosin staining. The morphological features of raw spermatozoa were evaluated (by Phase Contrast microscopy) after staining with Eosin-Nigrosin mixture or Nigrosin (alone), or after fixation with Hancock’s buffered formol saline solution. 42 raw pooled semen samples from 6 K›v›rc›k rams were used. The percentages of spermatozoa with abnormal acrosomes and total morphological abnormalities averaged 3.97% and 14.78% in Hancock’s solution, compared with averages of 10.07% and 18.54%; 7.97% and 18.45% for smears stained with Eosin-Nigrosin or Nigrosin (alone), respectively (P<0.05). The percentages of the same features for dead spermatozoa averaged 15.38% and 24.42%, compared with averages of 4.21% and 10.80% for live spermatozoa, respectively (P<0.05). These results suggest that staining procedures were detrimental to the acrosomes and total morphological features, thus increasing the total morphological and acrosomal abnormalities in dead ram spermatozoa.