Effects of storage duration on mitochondrial activity and dna fragmentation of post-thawed spermatozoa from several ongole grade bull in Indonesia

Several recent studies theoretically assumed that storage of frozen doses of semen in liquid nitrogen guarantees unlimited sperm functionality. However, several studies concluded that long-term storage causes decreased sperm quality. The purpose of this study was to evaluate the storage duration effect on mitochondrial activity and DNA integrity of Ongole Grade Bull post-Thawed spermatozoa from several Artificial Insemination Centre (AIC) in Indonesia. In this study, Ongole Grade Bull frozen semen that has been stored up to three years were investigated. According to the duration of storage, semen samples were divided into 7 groups (one month, three months, six months, nine months, one year, two years, and three years).This study used 42 straws, with 6 straws for each group were used. Samples were evaluated for sperm motility, viability, membrane integrity, mitochondria activity, and DNA fragmenta-tion. The results showed that one-month group sperm motility was (53.80), viability (72.75) membrane integrity (76.35), mitochondria activity (64.24), and DNA fragmentation (3.82). After 3 years of storage, the corresponding values were 39.52, 41.56, 48.25, 49.12, and 4.62. Sperm motility and viability remained unaffected up to 6^th months of storage, while membrane integrity started decreasing at 3^rd month (P<0.05). Mitochondria activity decreased during the 9^th months (P<0.05). In contrast to the previous results, DNA fragmentation did not increase significantly after 3 years of storage (P>0.05). Thus, post-thawed motility, viability, and membrane integrity of spermatozoa from Ongole Grade Bulls started decreasing at 6^th months of storage, mitochondria activity started decreasing after 9^th months, while sperm DNA integrity remained unaffected for up to three years of storage. © 2021 Elsevier B.V., All rights reserved.