Deoxyribonucleic acid (DNA) is the genetic material carried by paternal and maternal lines that would be passed on to the offspring. The integrity of the spermatozoa cell DNA affects the success of embryo development. DNA damage carried by the paternal line has an impact on the syngamy process, in which a certain amount of male and female gamete chromosomes unite to continue the division process. This study aimed to determine the effect of storage periods in liquid nitrogen on DNA fragmentation of post-thawed semen of Bali bull. This research was conducted at the Laboratory of Animal Physiology and Reproduction, Faculty of Animal Science, Universitas Gadjah Mada. Seventy-five semen straws produced from one bull were divided into 3 groups; each group consisted of 25 semen straws as long as 3, 6, and 8 months of storage in liquid nitrogen. The quality of thawed semen included motility, viability, abnormality, plasma membrane integrity, and DNA fragmentation were observed. The result showed that the sperm DNA fragmentation (%) which was stored for 3 months (6.33±0.38), 6 months (6.84±0.61), and 8 months (6.97±0.36) still in good conditions. Sperm motility, viability, and DNA fragmentation remained unaffected in different storage periods (p<0.05). Based on the result above, it could be concluded that storage period affects the abnormality and integrity of the plasma membrane, however, it does not affect the motility, viability, and DNA fragmentation of spermatozoa. The best quality of thawed frozen semen is obtained at 3 months of storage.
Keywords | Bali bull, DNA fragmentation, Liquid nitrogen, Spermatozoa, Storage periods