THE INFLUENCE OF ADDING GLUTATHIONE ON SEMEN CHARACTERISTICS OF SOHAGI RAMS

ABSTRACT
The present study was conducted to investigate the influence of adding glutathione (GSH) at levels of 0.4, 0.8 and 1.2 mM to egg yolk-tris extender (EYTE) used for preservation of semen at a temperature of 25oC for 0, 1, 2, 3, 4, 12 and 24 hours. A total of 10 Sohagi rams having 60-65 kg live body weight and aged 3-4 years were used for semen collection in this study. Semen was collected by artificial vagina set up at optimal conditions to induce a good ejaculatory thrust. Semen was collected twice a week in the morning (8 am) for 10 weeks. Each time semen was collected, all ejaculates (10 ejaculates) were pooled and divided into 4 parts and extended on egg yolk-Tris buffered extenders containing three levels of glutathione, 0.4, 0.8, 1.2 and control group of 0.0 mM. 
Semen of each treatment was diluted at a rate of one part of semen to 10 parts of egg yolk-Tris buffered extender at 30oC. Semen was evaluated after 0, 1, 2, 3, 4, 12 and 24 h at 25oC using the following in vitro fertility tests; sperm motility (%); livability (%); sperm abnormality (%) and spermatozoa with intact acrosome (%).
The addition of GSH to egg yolk-Tris buffer extender at levels 0.4, 0.8 and 1.2 mM improved semen quality. All GSH levels significantly (P<0.05) increased the percentages of sperm motility, sperm livability and intact acrosome while significantly (P<0.05) decrease sperm cells abnormalities. All sperm characteristics were significantly (P<0.05) affected by storage time, as motility, livability and intact acrosome showed significant (P<0.05) gradual reduction, while sperm abnormality showed significant (P<0.05) increase by progress of storage time up to 24 hours. The highest reduction rate was after 4 hours storage period. In conclusion, this study demonstrate that supplementation of GSH, at various concentrations, to diluted semen kept at 25oC exert beneficial effects on semen quality in term of sperm motility, livability and membrane stabilization of sperm cells. The best result was obtained with 0.4 mM GSH level in egg yolk extender when stored up to 12 h.