Cryopreservation of aseel cock sperm using different ratios of glycerol and iodixanol

The cryopreservation of sperm in mammals and birds is crucial for preserving genetic material, transmitting superior breeding traits to future generations, and preventing the extinction of endangered species. In ornamental poultry, preserving individuals with rare phenotypic and genotypic traits is critical for maintaining biodiversity and improving breeding programs. This study investigates the effects of glycerol and iodixanol, used in different concentrations during the freezing process of poultry sperm, on post-thaw sperm quality. Aseel roosters are highly valued in ornamental poultry due to their robust build, longevity, resilience, and distinctive phenotypic traits. In this study, semen samples were collected from ten Aseel roosters using the abdominal massage method, and pooling was performed. Six different diluent groups were prepared with varying concentrations of glycerol and iodixanol; these groups included 2.5% and 5% glycerol combined with iodixanol. Semen samples were loaded into mini straws and gradually frozen using an automatic freezing device. Post-thaw analyses revealed that groups containing 5% glycerol showed higher motility rates. In groups containing 2.5% glycerol, motility was lower, but the addition of iodixanol improved motility. No significant effect of iodixanol on progressive motility was observed. Flow cytometry results indicated that groups with 5% glycerol had a higher proportion of live spermatozoa, with the highest mitochondrial activity found in the group combining 5% glycerol and 2.5% iodixanol. Overall, groups containing 5% glycerol yielded better cryopreservation results. However, the addition of iodixanol to low glycerol concentrations had positive effects on total motility and mitochondrial activity. Future research is recommended to explore the use of different cryoprotectants and concentrations in poultry sperm cryopreservation.