Abstract
Abstract:
90 Friesian calves belonging to Alexandria governorates, Egypt, included in this study and classified into 3 groups, group A: Consist of 20 apparently clinically healthy calves kept as a control, group B: contains 35 calves shows respiratory manifestation, treated with traditional therapy, group C: includes 35 calves exhibit signs of respiratory affection, treated with the same traditional drugs in addition to green tea extract (GTE). Complete early rapid recovery observed in group C than traditionally treated calves. Significant changes in serum creatinine and activity of AST and ALT were observed in group B and C in comparison with healthy calves. There were a significant decreases in the mean values of total antioxidant capacity, catalase activity, reduced glutathione (GSH), glutathione peroxidase (GSH-Px) activity and super oxide dismutase (SOD) activity in group B in comparing with control animals and group (C), while the same previously mentioned values showed a significant increase in group C in comparing with group A and B. On the other hand there is a significant increase and significant decrease in the activity of lipid peroxidase in group B and C, respectively when comparing with control group and with each other. The investigation revealed a significant decreases in the mean values of sodium and chloride with significant increase in potassium level in group B when compared with both control calves and group (C), while the same previously mentioned elements showed non-significant changes in group C when compared with the other two groups.

Key words: Key words: green tea extract, oxidative stress, antioxidants, calves, respiratory disorders