Effect of Selenium Incorporated in Feed on the Hematological Profile of Tilapia ( Oreochromis niloticus )

The present study was aimed at the assessment of potential effect of selenium, supplemented in feed, on the hematological profile of tilapia (Oreochromis niloticus) while maintaining certain physicochemical parameters of water. Three doses differing merely in selenium contents viz. 2, 4, and 8 mg Se/kg of fish feed were formulated bearing in mind apiece dose as an independent treatment. Four cemented rectangular tanks (triplicated) were used after proper disinfection to ensure sustainable culture environment. 15 fish per tank were stocked after appropriate health examination weights ranging 10-25 g. Variations in different hematological parameters by counting of white blood cells, red blood cells, hemoglobin estimation, granulocytes (neutrophils, eosinophils, and basophils), agranulocytes (lymphocytes and monocytes) as well as weight and length gains were recorded and analyzed using one-way ANOVA. The results revealed that WBC’s counts were non-significantly (P=0.05) different among treatments 1, 2, 3 as well as in the selenium-deficient treatment. However, the counts of WBC’s, neutrophils, RBC’s and hemoglobin level was enhanced (P=0.05) in treatment-1 (2 mg Se/kg). On the contrary, hemoglobin level, neutrophil and RBC’s counts were significantly dropped (P=0.05) low in treatment-3 (8 mg Se/kg). The WBC’s counts were found lower in treatment-2 (4 mg Se/kg). Lymphocytes and monocytes were significantly higher in treatment-3 (8 mg Se/kg). This study has enlightened that the supplementation of selenium (2 mg/kg) in the feed of tilapia does not alter its inclusive hematological profile but promotes better physiological performance and productivity to enhance fish growth and paves the way towards increased supply of selenium-fortified fish meat.