Cryopreservation and evaluation of Akkaraman ram semen with 7-dehydrocholesterol

The experiment was conducted to determine the in vitro results of 7-dehydrocholesterol loaded cyclodextrin compound (7-DCLC) addition to tris extenders for freezing ram semen. Three Akkaraman rams, local species in Turkey, were used. Semen samples were extended with tris containing 0 mg (control), 1.5 mg, 2.5 mg and 3.5 mg/120x10(6) 7-DCLC and they were equilibrated to 4 degrees C and frozen in mini straws then stored in liquid nitrogen. Straws were thawed at 37 degrees C for 30 s in water bath for spermatological examination. Statistically significant differences were observed between 7-DCLC and control groups in terms of acrosome integrity, CASA motility, HOS test and viability after thawing (P<0.001). In all these parameters, control group had the lowest percentages. There was no statistically significant difference between groups in terms of DNA fragmentation, abnormal spermatozoa ratio, mitochondrial activation, lipid peroxidation and apoptosis level (P>0.05). In conclusion, it can be said that adding 7-DCLC to Akkaraman ram semen improved cell membrane cryosurvival. Besides, 7-DCLC can be used in tris extender instead of cholesterol loaded cyclodextrin (CLC) compounds for sperm cryopreservation.