The influence of different trehalose concentrations on sperm parameters of frozen-thawed semen of different rams during preservation in the reproductive season

The sheep artificial insemination with frozen-thawed semen have a low fertility rate because cryopreservation of ram semen is difficult.
The aim of this study was to investigate the effect of supplementation of diluent with different trehalose concentrations on during of storage cryopreservation of different rams’ semen in reproductive season.
Ejaculate samples were collected from six adult rams. Samples immediately were transported to the laboratory. After a primary evaluation, semen samples were diluted, with a Tris-based extender complemented with 50, 75, 100 mM trehalose and an extender containing no sugar as a control group. Semen samples were aspirated into 0.25 ml straws, cooled to 5°C and after frozen finally stored in liquid nitrogen. The frozen straws were evaluated for motility, progressive motility, percentage of live sperm and morphology for 15 days.
Achieved results showed that the highest percentage of alive sperms belonged to 75 mM trehalose and control group had the lowest percantage of alive sperms. The highest percentage of motility and progressive motility were recorded in concentrations of 75 mM and 100 mM, while the control group had the lowest percentage of motile sperm and progressive motility, on the other hand, no significant differences were observed in the percentages of abnormality the extender containing of trehalose and control group.
The highest percentage of alive sperms recorded for the Ghezel rams. Percentage of motility, progressive motility and abnormality in Ghezel-Merinos rams were better than other groups. The results of this study showed trehalozse improved cryopreservation of ram semen.