Effect of diets containing aqueous-alcoholic extract of olive leaf (Olea eurcpaea L.) on growth performance and some blood and immune parameters in common carp (Cyprinus carpio) fingerlings

This study evaluated the effects of different concentrations of olive leaf aqueous-alcoholic extract on growth performance and some blood and immune parameters in common carp (Cyprinus carpio) fingerlings. A total of 135 Common carp fingerlings with an average weight of 15 ± 3.4 g were fed with two diets containing 1 and 5 g/kg of aqueous-alcoholic extract of olive leaf randomly allotted to triplicate groups with 15 fish in each group for 8 weeks. After 8 weeks, growth parameters and some hematological and immunological parameters were assessed. The results showed that there was no significant difference in final weight, final length, weight rate, specific growth rate in two treatment groups (p>0.05). In both treated with olive leaf extract, there was a significant increase in the number of white blood cells and lymphocytes and a significant decrease in food conversion rate (p