Effects of oxidized glutathione, cysteine and taurine supplementations on motility charateristics of different goat spermatozoa types

This study aimed to determine the influences of antioxidants additives on motility characteristics of different goat spermatozoa types including frozen/thawed, fresh, and chilled samples. Ejaculates from five Shami bucks were collected during breeding and non-breeding seasons. Spermatozoa samples from the three types were incubated in media containing 2 and 4 mM oxidized glutathione (GSSG), 5 and 10 mM L-cysteine,10 and 25 mM taurine, and no additives (control). Motility characteristics were analyzed by a computer-aided sperm analyzer (CASA). Except for taurine, the addition of antioxidants resulted in a significant (p < 0.05) increase in the percentage of motile sperm (MOT %) after spermatozoa thawing. When fresh sperm samples were collected during the non-breeding season and treated with both GSSG and L-cysteine, the values of the velocity parameters VAP, VSL, and VCL increased significantly (p < 0.05). No significant effects were noted for the velocity parameters when 10 and 25 mM of taurine were added to the chilled spermatozoa, while GSSG and L-cysteine had principally affected MOT % of this spermatozoa type. The rapid spermatozoa subpopulation was the most influenced category by the three antioxidants compared to the slow and medium grades, especially in the case of fresh and frozen/thawed types. In conclusion, the effects of different antioxidants on goat spermatozoa motility largely depend on the used concentration and also on the type of spermatozoa pattern.