effect of methionine levels in starter diet on performance, immunity and blood parameter of arian 386

in order to investigate effect of methionine levels in starter diet on performance, immunity and blood parameter of arian broilers chickens during the starter period, a trial with 700 broiler chickens in a completely randomized design with 7 treatments, 5 replicates and 20 chicks in each experimental unit was performed. experimental groups were consisted of 0.38, 0.43, 0.48, 0.53, 0.58, 0.63 and 0.68% of methionine. other amino acids provided higher than the recommendation. live body weight at 7 and 14 days old, weight gain and feed conversion ratio at 0-7 and 0-14 periods were affected by methionine levels(p<0.05). at the age of 14, the highest body weight and best feed conversion ratio observed in the level of 0.43. srbc response, immunoglobulin g and m, heterophil to lymphocyte ratio and the number of white blood cells were not affected by methionine levels(p>0.05). also using level of methionine had no significant effects on phosphorous, calcium, triglycerides, cholesterol, hdl, uric acid, t3 and t4 and plasma protein levels(p>0.05).