Fewstudies havebeendoneontheeffectsoftrehalose supplementation in the cryopreser
vation of Angora buck semen. The objective of present study was to investigate the effects of the addition of trehalose at different doses in semen extenders, on invitro semen quality parameters, anti-oxidant enzymes activities and DNA damage after the freeze–thaw process in Angora buck semen. Semen samples from 5 mature Angora bucks (3 and 4 years of age) were used in thi sstudy. The bucks ,belonging to the Livestock Central Research Institute were maintained under uniform breeding condition. A total number of 40 ejaculates were collected twice a week from the bucks using an artificial vagina, during the breeding season and the semen pooled to minimize individual variation. Each pooled ejaculate was split into 7 equal aliquots and diluted (37◦C) with base extenders supplemented with the trehalose
(12.5, 25, 50, 75, 100and150mM),andabaseextenderwithnoadditives(control).Diluted
samples were aspirated into 0.25ml French straws, and equilibrated at 5◦C for 4h and
then were frozen at a digital freezing machine. The freezing extender supplemented with 50mM trehalose led to the greatest percentages of CASA motility (53.6±4.69), in comparison to the other group safter the freeze–thawing process (P<0.05). The additiono fdifferent doses of trehalose did not provide any significant effect on the percentages of post-thaw sperm motion characteristics (VAP, VSL and LIN), compared to the control (P>0.05). The freezing extender with 150mM trehalose group led to the highest percentages of acrosome abnormalities (P<0.05) and 50mM trehalose group had the lowest percentages of total abnormalities (P<0.001), in comparison to the others. There were no significance dif ferences in the DNA integrity among treatment groups (P>0.05). The different doses of trehalose did not show any effectiveness on the maintenance GPx, LPO, GSH, CAT and total antioxidant activities, when compared to the control (P>0.05). Therefore, the additions of 50mM and 75mM doses of trehalose will be useful in increasing post thaw motility on Angora buck semen.