Abstract:
The purpose of the research was the comparative assessment of the antioxidant status in blood plasma in cows, according to age (lactation) and milk production. Two groups (I and II) of cows in 1st and 3rd lactation and two other lots (III and IV) with an average daily milk production of 16 and 23 kg/day, respectively, were investigated. Total Antioxidant Activity (TAA) and Total Oxidative Activity (TOA); superoxide dismutase (SOD) and catalase (CAT) activity; the lipid hydroperoxide (LHP) and malondialdehyde (MDA) content were determined in order to assess the antioxidant plasma status. There is a tendency to maintain a lower level of TAA activity, while maintaining a higher level of CAT activity and plasma LHP content in cows of group II (3rd lactation) and those with higher milk levels (lot III). There is a tendency to maintain an increased MDA content in cows in the third lactation. 137 Thus, high productivity and age can be considered as potential factors for soliciting antioxidant status and initiating oxidative stress in dairy cows in the third lactation. 137 Thus, high productivity and age can be considered as potential factors for soliciting antioxidant status and initiating oxidative stress in dairy cows.