Abstract

Good quality frozen semen is a prerequisite for successful artificial insemination. Changes in the quality of sperm structure incur during semen processing of cryo-production. The current study, is, therefore, designed to evaluate the Muzaffarnagari cross-breed ram sperm at the fresh diluted stage, pre-freeze, and after freezing stages of frozen production. The semen collected was enlarged to include the A-part of 37°C egg yolk media. After cooling to 5ºC for 2h, B-part of tris-citric acid egg yolk glycerol media added with Apart and equilibrated at 5ºC for further 2h, transferred to 0.25 mL straws, placed in nitrogen vapor, frozen and thawed and then analyzed. Sperm samples were assessed in fresh, pre-freezing, and post Thawing phases for sperm motility, live sperm, ordinary sperm morphology, and intact sperm membrane. The mean percentage of sperm motility at fresh diluted stage (81.67±0.93%) was decreased significantly (p<0.05) pre-freezing stage (77.33±0.83%) because of refreshment and balance, and after freezing and thawing (44±2.45 percent) decreased further (p<0.05). The Mean percentage of live sperm was higher (p<0.05) at fresh diluted stage (91.27±0.57%) compared to pre-freeze (73.67±0.86%) and freezing stage (48.1±0.76%). The morphology normal sperm reduced significantly (p<0.05) from fresh diluted stage (85.27±0.64%) to pre-freezing stage (83.13±0.74). Their difference between the pre-freezing and the freezing stage is not significant (p>0.05) (80.2±1.28 percent). The mean intact sperm membrane percentage decreased significantly (p<0.05) from freshly diluted (82.4±0.77%) to pre-freezing (69.73±92%) and post-freezing (56.47±1.15%), respectively. The percentage of intact acrosomes of spermatozoa also significantly (p<0.05) decreased from fresh stage (95.8±0.39%) to pre-freeze (91.27±0.37%) and freezing stage (77.4±0.81%). In conclusion, during cryo- freezing periods the sperm showed the highest motility, live and membrane damage.