Effect of Different Thawing Time and High Temperature on Frozen Thawed Bull Semen Traits

: In this study was to investigate the effect of high temperature thawing and post-thaw cold shock application on sperm motility as well as acrosomal and total abnormalities of frozen bull semen. Four Holstein bulls were used to frozen semen in 0.25 mL straws. Semen of each bulls were thawed in 45 sec at 37°C (Group A = Control group) in 15 sec at 50°C (Group B) and 5 sec at 70°C (Group C) and post-thawing cold shock (300 sec at 5°C) were applied to all groups. After spermatozoa motility and morphological examinations are performed sperm samples were incubated at 35°C for 120 min and spermatological traits were repeated. Semen samples from the control and treatment groups were placed in an incubator taking into consideration the medium conditions (Modified buffered Hepes medium) and the time needed for spermatozoa to reach the fertilization site. Motility and morphological defects rates were determined with phase contrast microscopy and motility rate and speed with sperm fertility analyser (SFA-500). The Hancock’s solution was used for morphologic examination of spermatozoa (acrosome, other and total). In computer aided sperm fertility analyser, motility and movement were performed in according to the technique. In conclusion, it has been found that the conventional thawing method and rapid thawing technique are successful methods where the thawing method applied to Group B damaged spermatozoon viability. The rate of thawing in Group B did not protect the spermatozoa from dissolving or from the harmful effects of cold shock.