Effect of Olive Tree Extract on Growth, Survival and Activity Indices of Antioxidant Enzymes in Grass carp (Ctenopharyngodon idella)

The present study was performed to determine the effect of olive leaf extract on growth and antioxidant enzymes activity of Grass carp (Ctenopharyngodon idella). For this purpose, 3 diets containing extracts of different levels of olive leaf extract with concentrations (1, 2 and 3%) in the form of (T2, T3 and T4) and control diet (without extract (T1)) determination of the requirements of Grass carp was used for the extract of olive tree and the fish were fed the mentioned diets for 8 weeks. Results showed that daily growth rate, specific growth rate, condition factor, final weight, final length, weight gain and feed conversion efficiency were significantly higher in fish fed diets containing olive leaf extract compared to control (P<0.05). The highest feed conversion ratio was observed in control treatment. According to the results of the present study, the lowest levels of superoxide dismutase and glutathione peroxidase were observed in fish fed the control diet (p<0.05). Fish fed the T3 diet had the highest levels of malondialdehyde and the least amount of catalase (p <0.05). The results suggest that the use of different levels of olive tree leaf extract in Grass carp diets is appropriate and has a significant effect on all of these factors and when used in fish diets, the treatments were better than the control group.