The aim of this study was to evaluate the effects of eucalyptus leaf powder (ELP) and eucalyptus essential oil (EEO) on growth performance and immune response of broiler chickens. A total of 160 broiler chicks were assigned randomly into five dietary treatments from 7-42 days of age. Dietary treatments included: a control diet, control diets plus 1,000 or 3,000 mg/kg of ELP, and control diets plus 250 or 500 mg/kg of EEO. Dietary inclusion of ELP decreased body weight gain (BWG) during 7-28 days of age. Broilers fed diet containing 3,000 mg/kg of ELP had lower feed intake (FI) during 7-28 days compared to the other treatments. Broilers fed ELP or EEO had greater primary antibody response to sheep red blood cells (SRBC) compared to the control, but differences in secondary antibody response were not significant. In conclusion, dietary EEO has the potential to enhance immune response of broiler chickens.
