Effect of Different Levels of Nano-selenium on Performance, Blood Parameters, Immunity and Carcass Characteristics of BroilerChickens

The aim of the present study was to test the hypothesis that nano- seleniuminclusion in broilers’ diets can improve productivity and metabolic functions of broilers.Feed and water were provided ad libitum. A total of 180 one-day old male Ross 308 chicks were randomly assigned to six groups based on a completely randomized design, each with three replicates of 10 birds. One of the groups served as the control (CON) and was given a basal diet without further dietary supplementation, whereas the other five groups were offered the same starterandgrower diets further supplemented with dietary nano-selenium (NS) at 0.1 mg/kg of feed (NS1), 0.2 mg/kg of feed (NS2), 0.3 mg/kg of feed (NS3), 0.4 mg/kg of feed (NS4), and 0.5 mg/kg of feed (NS5). Nano-selenium dietary supplementation significantly improved weight gain and feed conversion ratio in starter (1st-21st day), grower (22nd-42nd day) and whole (1st-42nd) periods of experiment (P0.05). While, albumin levels in blood were decreased and anti-Newcastle disease hemagglutination-inhibition titer was increased after the dietary supplementation with the nano-selenium (P