Determination of oxidative stress indicator in dairycattle with subclinical mastitis

The most important and common disease among dairy cows is mastitis and it is still a big challenge for the dairy industry all over the world.Oxidative stress induced by reactive oxygen species(ROS) is a major cause of different diseases especially mastitis in cattle.there are few studies on the role of ROS in occurrence of subclinical mastitis.the objective of the persent study was to evaluate the changes in plasma malondialdehyde concentrations as a marker of lipid peroxidation of red blood cells and its relationship with somatic cell count(SCC) in milk as the marker of mammary inflammation in cattle.Heparinized blood and milk samples were collected from 45 healthy cows and 45 cows with subclinical mastitis from dairy farms in Tehran province,Iran.No significant difference (p>0.05) was seen between concentrations of malondialdehyde in the studied groups.there was a significant difference (p<0.001) between SCCs in the healthy cows with subclinical mastitis.the concentration of plasma malondialdehyde was higher in cows with subclinical mastitis which indicates mild increase in production of ROS in response to invading pathogens.