Effects of in vitro copper sulphate supplementation on the ejaculated sperm characteristics in water buff aloes ( Bubalus bubalis )

This study was carried out to investigate effects of copper sulphate (CuSO4) additive tosemen extenders on sperm parameters:progressive motility, viability, membrane integrityand DNA damage, after semen dilution and cryopreservation. Semen samples of 5 buffalobulls of 3-5 years old were collected at 5 different occasions during the autumn 2011. A totalnumber of 25 samples were used in each examination. Sperm progressive motility andviability were measured at 0 (T0), 60 (T1) and 120 (T2) min after diluting semen in tris-citricacid extender containing 0 (control), 0.004, 0.008, 0.016, 0.032 and 0.064 mg L-1CuSO4. Later,semen was diluted in a tris-citric acid-egg yolk-glycerol extender containing the sameamounts ofCuSO4, cooled to 4 C and kept refrigerated for 4 hr to equilibrate, spermprogressive motility, viability, membrane integrity and DNA damage were estimated. Then,semen was packed in 0.5 mL French straws and frozen in liquid nitrogen. Later, the frozensemen was thawed in 37 C water bath for 30 sec, and the same parameters as well as totalantioxidant capacity (TAC) of the frozen-thawed semen were estimated. The results showedthat copper additive at the rate of 0.032 mg L-1gives a better protection of sperms throughthe process of dilution, equilibration and freeze-thawing than that in control and other Cuconcentrations, while 0.064 mg L-1CuSO4had deleterious effect on the sperm.