Growth Performance, Carcass Characteristics and Intestinal Microflora of Broiler Chickens Fed Diets Containing Carum copticum Essential Oil

We evaluated the effects of dietary Carum copticum essential oil (CCEO) on growth performance, carcass characteristics and intestinal microflora of broiler chickens. A total of 240 Cobb broiler chickens were allocated to five dietary treatments, each with four replicates of 12 birds. Dietary treatments were prepared by formulating a corn-soybean meal-based diet free of antibiotics (Control) and supplementing the basal diet with three levels of CCEO at 150, 250, 350 mg/kg or antibiotic Virginiamycin at 200 mg/kg. Treatments were fed from 0 to 42 d of age. Body weight gain decreased linearly (P=0.035) with increasing CCEO while Virginiamycin increased body weight gain at 1 to 10 d compared to the control treatment (P < 0.05). Though feed consumption was not affected by CCEO, CCEO insignificantly improved feed conversion ratio (FCR) (P > 0.05). There were no differences in carcass characteristics among broiler chickens fed the control, CCEO and Virginiamycin diets (P > 0.05). Lactic acid bacteria in the cecum and ileum at 42 d of age were not influenced by the treatments (P > 0.05) but there was a linear increase of the log numbers of E. coli in the ileum (P=0.02) with increasing CCEO (P < 0.05). In conclusion, supplementing CCEO to diet at 150 mg/kg improve the growth performance, decrease undesirable intestinal bacteria in broiler chickens and is an adequate alternative to antibiotics.