Safarizadeh A. and Zakeri A.
A total of 96 one day-old Ross 308 chickens, divided, in to 12 groups (3 treatment and 4 replicate pens per treatment and 8 chickens per pens) in a same environmental conditions. Group A, consider as control group and group B and C considers as experimental groups. From first day, vitamin A premix was added to group B diets and complex of vitamin E premix and selenium was added to group C diets. Blood sampling for study about humoral immunity (HI) were in 3 period , first sampling was at 9th day of breeding , second sampling was at 2 weeks after first sampling and last sampling was at 42nd day of breeding (last day of period). In blood sampling for HI test, 2 cc blood was derived from each samples and for study about growth factor, 8 chickens per replicate were randomly chosen. Birds fed vitamin A and complex vitamin E and selenium containing diets exhibited significant difference, against Newcastle disease’s vaccine (p<0.05). Consequently, vitamin A and complex of vitamin E and selenium, improve humoral immune system in broiler chickens, but exhibited no effects on growth factor in broiler chickens.