Conservation of ram semen at 5 ºC using medium supplemented with 0.5, 1.0 and 5.0 mM of reduced glutathione
The experiment was carried out to determine the most recommendable concentration of reduced glutathione (GSH) to be used during refrigeration of ram semen at 5 °C. Each of a total of 12 ejaculates from two Pelibuey rams was divided into four aliquots corresponding to the GSH concentrations evaluated (0.0, 0.5, 1.0 and 5 mM), which were stored under refrigeration (5 °C) for 24 h. Evaluation of motility and viability was performed at 0, 1, 2 and 24 h of storage. At 24 h, sperm motility was also evaluated at 37 °C (reactivation). At 0, 1 and 2 h of storage there were no significant differences in sperm motility among the different concentrations of GSH. At 24 h, the concentration of 5 mM resulted in the highest (p <0.05) sperm motility (29.22%) and the highest (p <0.05) percentage of mobility during the reactivation (80.29%). As for viability, at 24 h of storage, the samples diluted with 5 mM GSH had 81.44% live spermatozoa. It is concluded that the activity of GSH as an antioxidant and protector during storage at 5 °C is dependent on concentration and storage time.