The high lactation performance or parity in dairy cows may affect intrauterine oxidative stress (OS) status. This study aimed to investigate the effects of milk yield, blood β-hydroxybutyrate (BHBA) concentrations, and parity on oxidative stress (diacron-reactive oxygen metabolites d-ROMs) or antioxidant activity (biological antioxidant potential BAP) in the uterine flush fluid of lactating Holstein Friesian dairy cows. Uterine flush fluid samples were collected at 4, 5, 6, and 8 weeks postpartum (n = 43), and d-ROMs and BAP were measured. d-ROMs, BAP, and oxidative stress index (OSI) were investigated in relation to the correlation between milk yield and BHBA concentrations. Cows were classified into primiparous cow groups (P group, n = 11), biparous cow group (B group, n = 5), and the third or more calving groups (M group, n = 27); d-ROMs, BAP, and OSI changes were evaluated across the groups. No significant correlations were noted between milk yield, blood BHBA concentrations, and d-ROMs, BAP, or OSI. The M group exhibited higher d-ROMs and OSI than the P group at 5 weeks, and the M group had a higher OSI than the B group at 6 weeks. Therefore, parity may influence uterine OS and antioxidant activity.
Hagita et al. (Thu,) studied this question.