الفهرس 
Chemical structures of seleniumOnly 14 pages are availabe for public view
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Abstract
This study was carried out in a broiler farm under the supervision of Animal Production Department, Faculty of Agriculture, Tanta University from May to during the period from March to May 2016. To investigate the effects of dietary Nano selenium, vitamin E and their interaction on the growth performance, blood biochemical profiles and immune response of Cobb broilers. Two hundred and forty one-day-old unsexed Cobb broiler chicks were used in this experiment. Birds were legs-banded, individually weighed to the nearest gram, and randomly distributed into four equal experimental groups; with three replicates of 20 chicks each. The average initial body weights of the treatments groups were nearly similar with no observed significant differences. The chicks were offered three cornsoybean meal basal mash diets that were formulated to meet or exceed the nutritional requirement of growing chicks as recommended by the National Research Council (NRC). The experimental designed was followed by T1 Basal diet supplemented with 0.5 mg/kg Nano selenium T2 Basal diet plus 50 mg/kg vitamin-E T3 Basal diet containing 0.5 mg/kg Nano selenium treated with50 mg/kg vitamin-E All birds were subjected to the same managerial, hygienic and environmental conditions. The birds were grown in floor litter condition and subjected to 24 hrs which extended to 5 weeks of age. The house temperature was kept at about 34ºC during the first 3 days, 32ºC during next 4 days and thereafter, gradually decreased by 2-3ºC weekly down to 22-24ºC. Mash feed form and water were available ad labium throughout the experimental period. Individual live body weight and feed intake were recorded weekly during the experiment. Growth rate, weight gain, feed conversion ratio and performance index were calculated on a group. At the end of the feeding trial, all birds were fasted for 12 hrs prior to final sampling. Five birds from each replicate were randomly selected weighed, slaughtered by slitting the jugular vein of the birds in the morning, then after slaughter and complete bleeding scalded and defeathered. Carcasses were eviscerated manually and weighed. Liver, spleen, burse, gizzard and digestive tract were removed carefully and weighed. All organs weights were expressed as percentage of body weight and subjected to arcsine transformation. At the end of the experiment, five birds from each replicate were slaughtered after fasting for 12 hrs. Ten ml of blood was obtained from each birds in a sterile centrifuge tube containing heparin (20 IU/ml) for determine some blood constituents. Plasma was obtained immediately by centrifugation of heparin zed blood for 10 min. at 3000 rpm and frozen rapidly in ependorf tubes until the time of analysis.