Effects of ribwort plantain (Plantago lanceolata L.) extract on growth performance, blood parameters, immune system and antioxidant enzyme activity of rainbow trout (Oncorhynchus mykiss W.)

In this thesis study, different doses of ribwort plantain extract (Plantago lanceolata) were added to rainbow trout (Oncorhynchus mykiss) feed and changes in growth performance, hematologic parameters, immune system and antioxidant enzyme activities of fish were investigated. For this purpose, aqueous methanolic extraction of ribwort plantain (D) were performed and obtained extracts were mixed with feed in proportion of 1%, 2% and 3%. Fish, 3 experimental groups and 1 control group (3 replicates of each group), were placed in 12 tanks (100-liter) and fed with prepared feed for 90 days. On the 30th, 60th and 90th days liver, muscle and blood samples were taken from fish for analyses. In the study; erythrocyte, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, oxidative radical production, myeloperoxidase activity, lysozyme activity, superoxide dismutase (SOD) activity, catalase (CAT) activity, glutathione peroxidase (GPx) activity, glucose-6-phosphate dehydrogenase (G6PDH) activity, lipid peroxidation, weight gain, specific growth rate and feed conversion ratio values of fish were determined. According to the results, when the hematological values were investigated, there was no significant difference between the control group and the experimental groups (p> 0.05). When immunological changes were evaluated, it was seen that lysozyme activity decreased compared to the control group weheras oxidative radical production and myelporoxidase activity were increased significantly. In terms of antioxidant enzyme activities, it was observed that ribwort plant had no effect on SOD and CAT values. However the increase of GPx and G6PDH values in 3% D group was statistically significant. According to the findings, it was concluded that the supplementation of ribwort plantain to the rainbow trout feed could promote the antioxidant property and can be used as an immunostimulant.