Relationship between total antioxidant/oxidant status, and oxidative stress index and superovulation response in donor cows

Abstract

• TAS, TOS, and OSI affect superovulation response in donor cows. • Positive correlation was determined between TAS and transferable embryo count, and embryo quality. • TOS and OSI were negatively correlated with the count of transferable embryo. • Positive correlation was found between unfertilized oocyte count and TOS, and OSI. The aim of the present study was to determine the effects of serum total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) on counts of corpus luteum, transferable embryo, and embryo quality in cows treated with superovulation protocol. A total of 60 Simmental cows (postpartum 90 to 120 days) were used. The donors were treated with a 9 day-progesterone based estrus synchronization protocol. On the 7th day of the progesterone treatment, donors were treated with FSH twice daily as decreasing doses for 4 days. On day 9, PGF 2α injection was performed in the morning and progesterone source was removed in the evening. The cows were inseminated twice artificially on day 11 at 12 hours interval. On the day of artificial insemination, blood samples were collected to determine serum TAS, TOS and OSI concentrations. Uterine flushing was performed on day 7 after artificial insemination. Serum TAS, TOS and OSI concentrations of cows were 1.62 μmol/L, 5.44 μmol/L and 0.45 AU, respectively. There was a positive correlation between TAS concentration and the counts of transferable embryo, Code I and II quality embryo ( P <0.05). TOS and OSI concentrations were negatively correlated with the counts of transferable embryo and Code I embryo, and positively correlated with unfertilized oocyte counts ( P <0.05). As a result, it was concluded that TAS, TOS, and OSI affected the counts of transferable embryo, embryo quality, and unfertilized oocyte in donor cows.