The effect of different extenders and different levels of trehalose sugar on quality of Dalagh ram semen in frozen condition

In artificial insemination of farm animals, frozen sperm is usually used. Sperm cryopreservation is one of the important methods for maintain and preserve genetic resources, which as one of the methods of assisted reproductive, can maintain the quality of sperm. Since beginning the time of artificial insemination technique, different diluents have been used to maintain and preserve semen in liquid and frozen condition. Extender composition and nature are of great importance in the viability of sperm. To this end, the aim of this research was to evaluate effects of milk, Tris-chicken egg yolk and Tris-turkey egg yolk extenders and different levels of trehalose sugar (0, 80, 100 and 120 mM) on Dalagh ram semen quality after freezing-thawing process.
In this research semen samples were collected from four Dalagh rams in the age of 2-3 years using artificial vagina. Then samples were diluted in different extenders and received different trehalose sugar treatments. Semen samples were aspirated into 0.5 ml straws and cooled to 4°C within 150 min and then frozen in liquid nitrogen. Frozen straws were transferred to a tank containing liquid nitrogen. After thawing spermatozoa quality parameters including percentage of sperm motility, viability, membrane integrity and sperm normality were evaluated. This experiment was carried out in 4×3 factorial arrangement with the use of completely randomized design. Treatments were included different levels of trehalose sugar (0 , 80 , 100 , 120 mM) and different extenders (milk and Tris-chicken egg yolk and Tris-turkey egg yolk). The obtained data from this study were analyzed by ANOVA procedure of Statistical Analysis System SAS (version 9.1). Comparison of data means were performed by Tukey test at the level of %1 error.
The results of this research showed effects different levels of trehalose sugar, on the percentage of sperm motility, viability, membrane integrity and sperm normality were significant (P In general, considering all the indices evaluated for the dilution of Dalagh ram semen, the addition of 120 mM trehalose sugar in Tris-turkey egg yolk extender showed a better response than other treatments after freezing-thawing process.