Anise oil dosage and its effect on growth performance and jejunal lesions during a Clostridium perfringens challenge in battery trials,and growth performance in a floor pen trial,

Anise oil (AO) is a phytochemical with antibiotic properties and it reduces the growth of Clostridium perfringens in vitro, which is the main causal agent of necrotic enteritis. A series of battery experiments was conducted to determine an AO dosage to feed to broilers and its effect during 2 C. perfringens challenges, and a floor pen experiment to determine its effect in performance. Anise oil linearly reduced (P < 0.05) ADFI and ADG, but feeding broilers 500 to 2,000 mg/kg of AO resulted in similar performance with positive control (PC) fed broilers. Broilers were challenged on d 10 (Experiment 2) or on d 10 and 13 (Experiment 3). Broilers fed AO had lower (P < 0.05) ADFI and ADG compared with broilers fed PC from zero to 18 d (Experiment 2). Growth performance of broilers fed AO was not affected (P > 0.05) during Experiment 3. In both challenges, the jejunum of broilers fed AO had fewer and milder (P < 0.05) lesions compared with broilers fed PC or negative control (NC) diets. In a floor pen trial, 1,000 mg/kg of AO was fed to broilers from zero to 42 days. Broilers fed AO or PC had similar (P > 0.10) growth performance for the entire trial. Broilers fed PC or AO had greater ADG (P < 0.05) and tended (P = 0.07) to be heavier than broilers fed NC at the end of the trial. Breast yield percentage was similar (P > 0.10) among broilers fed any of the dietary treatments. Residues of AO were not present at detectable levels in breast meat.