Efficacy of Excoecaria agallocha on hematological parameters in hybrid tilapia (Oreochromis niloticus) after experimental challenge with Streptococcus agalactiae

The potential of milky mangrove Excoecaria agallocha leaf extracts has been utilized in traditional medicine in various parts of the world. Blood is an important indicator of health and is a pathological mirror of the entire body. Therefore, the effects of E. agallocha leaf extract on hematology indices of hybrid tilapia (Oreochromis niloticus) were investigated. Experimental fish were randomly divided into seven groups. Groups 1 to 5 were fed medicated feed at five different concentrations (10, 20, 30, 40 and 50 mg kg-1) of E. agallocha leaf extract. Group 6 was given Flumequine (25 mg kg-1) and group 7 was fed with untreated feed (control) for 28 days before they were intraperitoneally exposed to 4x105cfu CFU ml-1 S. agalactiae. The results revealed that the group fed medicated feed at 50 mg kg-1 was the most effective concentration and showed no significant difference (p >0.05) compared to control and antibiotic groups on blood parameters (red blood cell, globulin, total serum protein, mean cell hemoglobin, and mean cell hemoglobin concentration) with the highest survival rate 99.67% within experimental groups. Overall, our results indicated the potential of E. agallocha could prove to be a hematological profile enhancer which can help fish combat bacterial infections. It was concluded that increase in the white blood cell count observed in fish administered with E. agallocha leaf extract at 50 mg kg-1 suggests that E. agallocha extract contains agents that could stimulate the production of leucocytes and serve as an immune booster and prevent the risk of anemia.