Aim of the present study was to monitor pre-freeze and post-thaw semen quality of Sahiwal bulls after addition of different concentrations of alpha lipoic acid (ALA) to the extender. Semen of four Sahiwal bulls was collected two times per week for four weeks with an artificial vagina. Ejaculates collected on each collection day from four bulls were pooled, split into four equal parts and diluted with tris-egg yolk-citrate-glycerol extender containing 0.500, 0.250, 0.125 and 0.000 mM (control) ALA. Diluted samples were filled in 0.5 ml straws, frozen and stored for at least 24 hours in liquid nitrogen. Pre-freeze and post-thaw quality was assessed in terms of sperm motility, plasma membrane integrity, live sperm percentage and acrosome integrity. Results indicated higher (P<0.05) mean values for pre-freeze and post-thaw sperm motility, plasma membrane integrity, live sperm percentage and acrosome integrity for samples diluted in extender having 0.250 and 0.125 mM ALA compared to samples diluted in extender containing 0.500 mM ALA and control extender. Moreover, higher mean values (P<0.05) of these characteristics were observed in samples diluted in extender containing 0.250 mM ALA compared to those diluted in extender containing 0.125 mM ALA. However, samples diluted with 0.500 mM ALA showed lower (P<0.05) pre-freeze and post-thaw semen quality than control samples. It was concluded that ALA at a concentration of 0.250 mM significantly improved pre-freeze and post-thaw characteristics of Sahiwal bull semen. However, field trials regarding effects of adding different concentrations of ALA to semen extender on fertility of frozen-thawed semen are necessary before making any recommendations in this regard.

To Cite This Article: Ahmad SB, Ahmad I, Ahmad N, Qureshi ZI, Jamil H, Ali Q and Ashfaq K, 2018. Effect of addition of different concentrations of alpha lipoic acid to tris egg yolk citrate glycerol extender on cryopreservation of Sahiwal bull spermatozoa. Pak Vet J, 38(3): 301-305. http://dx.doi.org/10.29261/pakvetj/2018.060