In this study semen from Nili Ravi buffalo bulls (n=16) was divided into two groups (each with n=08) on the basis of age factor. Further sub division was done in such a way that every day six bulls were used in collection and evaluation and subjected to the different inclusion levels of BHT @ 0.5mM, I.0mM, 1.5Mm, 2.0mM, 2.5mM, 3.0mM One group (control) received zero inclusion level of BHT. Semen was evaluated, diluted, cooled, filled in 0.5ml straws, equilibrated at 4°C for 4 hours and frozen in liquid nitrogen. After storage, semen was thawed and evaluated for percentage motility of spermatozoa, plasma membrane integrity (HOS assay), acrosome integrity (NAR) and vitality (Live/Dead). Data collected were presented as mean ± SD, treatment groups were compared using one way ANOVA. Results were compared by using the Duncan Multiple Range Test. Results of this study revealed that addition of 2.0 mM BHT in semen extender is useful from the preservation point of view. In conclusion addition of 2.0 mM BHT in semen extender improved post thaw semen quality, which indicates that the importance of an antioxidant in semen extender cannot be neglected.

Dr.Abid Hussain SHAHZAD is working as lecturer in Theriogenology section at University of Veterinary and Animal Sciences, Lahore (Jhang Campus). He completed his M.Phil under the supervision of Prof.Dr.Ijaz Ahmad. Currently he is doing One year research training at Uludag University,Bursa with Prof.Dr.Deniz NAK under 2216 program offered by TUBITAK