dietary different levels of coriander essential oil for broilers: effect on growth performance, carcass characteristics and blood immune parameters

abstract dietary essential oils may be used as alternatives to antibiotics and its might improve poultry performance. the aim of this study was to investigate the effects of coriander essential oil on growth performance, carcass characteristics and immune system in broiler chickens. two hundred day-old broiler chickens (ross 308) were allocated to 5 treatments, 4 replications with a completely randomized design during 42 days of age. experimental treatments consisted of control treatment (basal diet) or basal diets containing different levels of coriander essential oil (100, 200 and 300 mg/kg) and 600 mg/kg flavophospholipol antibiotic. weight gain, feed intake and feed conversion ratio were measured weekly. results in total period showed that highest feed intake was observed in antibiotic compared with 100 and 200 mg/kg coriander essential oil treatments (p<0.01). also, the highest weight gain at antibiotic and at the level of 300 mg/kg coriander essential oil treatments compared with control and at the level of 100 mg/kg coriander essential oil was observed (p<0.01). at final, the best feed conversion rate was observed at coriander essential oil and antibiotic treatments (p<0.01). highest carcass and thigh proportional weights and lowest gastrointestinal proportional weights of broilers were observed at coriander essential oil and antibiotic treatments compared with control treatment (p<0.05). immune system parameters were unaffected by dietary supplementation of experimental treatments. the results demonstrated that addition of the coriander essential oil to the feed as well as antibiotic had a significant effect on growth performance and carcass characteristics at 42 days of age.