The current investigation was carried out to determine the impacts of different levels of vitamin K (VK) on the growth performance, hematological parameters, and immunological response of all-male juveniles of Nile tilapia ( O. niloticus ). VK3 (menadione) was added in five concentrations (0.0, 2.0, 4.0, 8.0, and 12.0 mg kg –1 diet) in five isonitrogenous (30% cp), isocaloric (18.61 MJ kg –1 ) diets. The fish were fed the diet...