Cryopreservation of goat spermatozoa in the Mekong Delta region of Vietnam: evaluating cryoprotectant effectiveness

Abstract

Conserving and improving the quality of breeds is crucial for enhancing small ruminant production in Vietnam. To support this purpose, cryopreservation was offered as a promising method for semen preservation and maintaining genetic diversity. Moreover, many small-scale farmers in Mekong Delta rely on goats for both income and nutrition, making them an important part of farming activities. This study aimed to develop a sperm cryopreservation protocol and identify the optimal cryoprotectant for goat sperm in the Mekong Delta region of Vietnam. Semen samples were diluted with TCG-EggYolk freezing medium containing cryoprotectant agent (CPA) in a 1:1 ratio. The samples were then placed in 0.5 mL French straws, cooled to 15 °C and 5 °C, and subjected to nitrogen vapor before being immersed in liquid nitrogen at -196 °C. Experiment 1 utilized Glycerol as the CPA in concentrations of 0 %, 5 %, 8 %, and 11 %. Experiment 2 employed dimethyl sulfoxide (DMSO) as the CPA with the same concentrations. Thawed samples were evaluated for sperm quality. Results indicated that in Experiment 1, increasing the Glycerol concentration improved the overall motility, viability, and membrane integrity of sperm. The best outcomes were achieved with 8 % Glycerol, resulting in progressive motility of 57.5 % (P<0.05). In Experiment 2, the extender containing 8 % DMSO demonstrated significantly better performance in terms of overall motility, viability, and membrane integrity compared to 5 % or 11 % DMSO. Progressive motility was 53.5 % (P<0.05). In conclusion, the study determined that using 8 % Glycerol or 8 % DMSO is the optimal choice for freezing goat sperm in the Mekong Delta region of Vietnam.