Preservation of semen from Kintamani Bali dogs by freezing method

OBJECTIVE: To explore the effect of glycerol at different concentrations using different extenders on DNA fragmentation and motility of frozen-thawed Kintamani Bali dog spermatozoa. MATERIALS AND METHODS: Sample was collected from four mature Kintamani Bali dogs. Each ejaculate was prepared for cryopreservation with two different semen extenders; egg yolk Tris extender and coconut water-based extender. For each extender, three different glycerol concentrations were used; 4%, 6%, and 8%. Each of the six aliquots was loaded into 0.5 ml cryotube, placed on a styrofoam box 5 cm over liquid nitrogen for 10 min, and immersed in liquid nitrogen up to 8 min. Then, the frozen cryotubes were transferred into liquid nitrogen container. The cryotubes were thawed in a water bath at 38.5°C for 120 sec. After equilibration and thawing, each sample was assessed for motility parameters and for DNA fragmentation. RESULTS: The addition of 6% glycerol to extenders revealed the most effective addition of glycerol on motility and sperm DNA fragmentation after equilibrium and post-thawing. CONCLUSION: It is concluded that both extenders with the addition of 6% glycerol are safe to be used as an extender in Kintamani Bali dog semen preservation, and DNA fragmentation of Kintamani Bali dog spermatozoa was not influenced by the freezing procedure.