Increasing the fertility of Sapudi sheep semen at 5°C storage temperature with the addition of oxytocin in a diluent of skim milk, egg yolk, and citrate

Abstract

Background: Artificial insemination in sheep is one of the important reproductive technologies that accelerate the increase in the population of Sapudi sheep. The success of fertilization is higher with the addition of oxytocin in semen than with exogenous oxytocin administration. The semen diluents used were milk and egg yolk citrate. Aim: This study aimed to determine the effect of oxytocin inclusion in extender on viability, motility, plasma membrane integrity, malondialdehyde (MDA) levels, and catalase levels in Sapudi sheep semen stored at 5°C. Methods: Semen was collected with an artificial vagina and examined macroscopically and microscopically. Each ejaculate was divided into four parts according to the treatment group. The control group (T0) consisted of fresh semen diluted in a skim milk–egg yolk–citrate extender without oxytocin addition. The treatment groups received the same extender supplemented with oxytocin at different concentrations: T1 with 5 IU/100 ml, T2 with 10 IU/100 ml, and T3 with 15 IU/100 ml of extender. All treatments were stored at 5°C and evaluated daily for 5 days. Results: Group T2 had the highest viability, motility, intact plasma membrane, and catalase enzyme levels (p < 0.05) and the lowest MDA levels (p < 0.05). In group T3, the viability, motility, intact plasma membrane, and catalase enzyme levels decreased (p < 0.05), and the MDA levels increased (p < 0.05) compared with the dose in group T2. Conclusion: This study indicated that the inclusion of 10 IU/100 ml of oxytocin in skim milk–egg yolk–citrate extender can maintain the quality of Sapudi ram semen with a motility of more than 40% after 5 days of refrigerated storage.