Assessment of oxidative stress indexes and BCS in clinical mastitis cows in comparison with healthy cows

Mastitis, as one of the most important diseases in cattle, is the cause of the greatest economic loss in the dairy industry. The occurrence of mastitis is associated with the development of immune responses and an increase in the level of reactive oxygen species (ROS). The production of high amounts of ROS and the lack of optimal amounts of antioxidant compounds are associated with oxidative stress. The aim of this study was to evaluate the status of oxidative stress indices in cows with clinical mastitis. In this study, two groups of cows were studied: healthy cows and cows with clinical mastitis. The body condition score (BCS) of the cows was assessed at the time of blood sampling. Total antioxidant capacity and selenium concentration were significantly higher in healthy cows than sick cows. Healthy cows had lower malondialdehyde concentrations than sick cows, although this difference was not statistically significant. When the cows were divided into three groups according to body score, the amount of glutathione peroxidase in cows with high body scores was significantly lower than the other two groups. The amount of malondialdehyde and the number of milk somatic cells in cows with high and moderate body scores were significantly higher than the other group. The results show that there are changes in the antioxidant defense of cows with mastitis that lead to oxidative damage, so the use of antioxidants is necessary to control mastitis. Obese cows are also more sensitive to oxidative stress.