Sperm HOS Test Score in Frieswal Bulls and its Relationship With Morphology, Viability and Cryo-Preservability

摘要

Seminal ejaculates of crossbred Frieswal bulls (55) were classified into 3 categories (viz. category 1, category 2 and category 3 having < 50%, 50-70% and > 70% HOS responsiveness, respectively) based on their spermatozoa! response to hypo-osmotic solution (HOS). Sperm abnormalities, viability and damaged acrosome varied significantly (P<0.01) with different levels of HOS responsiveness. Ejaculates having < 50% HOS responsive sperm (category 1) had significantly (P<0.01) lower sperm concentration, initial and post thaw motility than ejaculates with 50-70% HOS score. Similarly category 3 ejaculates had better attributes as compared to category 2. Total abnormal sperm per cent was highest in category 1, followed by category 2 and lowest in category 3.Dead and damaged acrosome per cent was highest in category 1 and lowest in category 3. Different levels of HOS score in the ejaculates showed significant differences in their cryo-preservability. In category 3, 54.96% ejaculates yielded >40% post thaw motility, whereas in category 2 and 1, it was only 25.80 and 7.27%, respectively. HOS score showed significant positive correlation with sperm concentration, motility and viability but negative correlation with cyto-morphological abnormalities and damagedacrosome. It was concluded that seminal ejaculates that had > 70% HOS score showed better sperm qualitative attributes in terms of motility, morphology, viability, acrosomal status and cryo-preservability as compared to ejaculates having <70% HOS score.Ejaculates having < 50% HOS score were mostly of inferior quality and unacceptable freezability, where as ejaculates having 50-70% HOS scores exhibit satisfactory sperm qualitative attributes but suffered from questionable freezability.