Evaluation of quality of grass carp (Ctenopharyngodon idella) sperm during short-term storage

Short-term storage allows for the safe transportation and handling of gametes for short periods, ranging from hours to weeks. This method facilitates gamete storage, enables sperm selection for breeding programs, and contributes to creating gene banks. In this study, we evaluated the motility time and percentage of motile spermatozoa in grass carp (Ctenopharyngodon idella) at intervals of 0, 24, 48, 72, and 96 hours after storage at a chilled temperature of 4 °C. Semen from eight mature males, with a mean weight of 7837.5 ± 1132.5 g, was used for this purpose. For the sampling process, the fish were anesthetized using clove powder extract. Semen was then collected by applying gentle pressure to the abdominal region. Half a mL of each semen sample was placed in plastic tubes and stored under chilled conditions without dilution in a storage medium. The examination of these samples was conducted at various times after storage. The results indicate that 48 hours after chilled storage, there was a significant difference in the percentage of motile spermatozoa compared to the initial time (P < 0.05). Furthermore, there were significant differences in motility time from 72 hours after chilled storage compared to the initial time (P < 0.05). All semen samples remained active for up to 48 hours after being chilled. After 96 hours of storage, the mean activity in the three remaining samples was 20.0 ± 10.0%. According to the results, the best quality of the samples was observed within 24 hours of chilled storage. Therefore, storing grass carp semen in chilled conditions for up to 24 hours can facilitate the artificial insemination process in hatchery centers.