efficiency of echinacea purpurea l. on total antioxidant activity in serum of broiler chicks

background & aim: this experiment was conducted to examine the effect of different levels of echinacea purpurea (ep) in comparison with an antibiotic (flavofosfolipol) on total antioxidant activity (aoa) in serum of broiler chicks. experimental: in this trial 240 one-day-old broiler chicks (ross 308) were weighed and randomly assigned to the 5 treatment groups, each with 4 replicates with 12 broilers. the 5 treatments were as follows: 1. basal diet (control); 2. basal diet + antibiotic (4.5 mg flavofosfolipol/kg diet); 3. basal diet + dried aerial part powder of ep (5 g/kg diet); 4. basal diet + dried aerial part powder of ep (10 g/kg diet); 5. basal diet + tincture extract (0.25 g/kg diet). the contents of flavonol-o-glycosides as quescetin was determined by spectrophotometer method, and the amount of flavonol-o- glycosides as quescetin in 5 g/kg diet ep to alcoholic extract was equal. at 42 days blood sample was taken and analyzed for total antioxidant activity (aoa) of serum blood.  results & discussion: the results showed that using of 10 g/kg diet ep led to the highest aoa (m mol/lit) compared to other groups. alcoholic extract supplementation to diet resulted higher aoa than those control and antibiotic treatments but not significant. the aoa increased in broilers fed diet containing 5 g ep/kg diet than those control, alcoholic extract and antibiotic treatments but not significantly. industrial and practical recommendations: the results of this trial showed that, using of 10 g ep/kg diet improved total antioxidant activity in serum of broiler chicks. according to the risk of producing the microbial population resistant to antibiotic because of continuous use antibiotics in animals diet in fields and due to the findings of this experiment and other experiments, the powder of the top organs of echinacea purpurea can be used as a suitable alternatives for antibiotic in food diet of the poultry.