Effect of dietary nano α-tocopherol acetate plus selenium on productivity, immune status, intestinal morphometry and carcass traits of broiler chicken

21 Background: Nano-vitamins and minerals are used in animal nutrition to improve 22 performance and health of broiler chickens as a potential alternative to antibiotic 23 growth promoters. Objective: To evaluate the effect of several levels of a dietary 24 nano α-tocopherol acetate plus selenium compound (NTS) on growth, intestinal 25 histomorphometry, carcass traits, and immune status of broiler chickens. 26 Methods: A total of 240 one-day-old Ross 308 chickens were randomly divided 27 into four groups, each one containing three pens (n=20 in each pen). Four doses of 28 nano α-tocopherol acetate and SE (0, 5, 7, and 10 mg/kg) were included in the 29 basal diet for 42 days. Results: The final body weight (BW), cumulative body 30 weight gain (BWG), and final feed conversion ratio (FCR) significantly improved 31 when NTS levels were increased (P<0.05). The carcass traits and weight of 32 internal organs enhanced in the groups fed with 7 and 10 mg/kg NTS. With high 33 doses of NTS significantly increased the immune vaccine titers against Newcastle 34 disease (ND), avian influenza (AI) virus, infectious Bursal disease (IBD), and 35 infectious bronchitis (IB). Moreover, dietary addition of NTS improved some 36 intestinal morphometric properties. Conclusion: Thus, NTS (7 and 10 mg/kg) can 37 be added in poultry rations to improve production, carcass characteristics, and 38 immune status of broilers. Further studies are needed to evaluate NTS residues in 39 meat. 40