Effect of dietary oregano (Origanum vulgare L.) essential oil on growth performance, cecal microflora and serum antioxidant activity of broiler chickens

Abstract

A feeding trial was conducted to investigate the effects of dietary oregano ( Origanum vulgare L.) essential oil (OEO) on broiler performance, cecal microflora and serum antioxidant activity. One hundred and eighty (180) 1-day old broiler chicks were randomly divided into four groups. Group I was kept as normal control and received basal diet. Birds of groups II, III and IV were treated with basal diet supplemented with 300, 600 and 1200 mg/kg of OEO. Inclusion of 600 mg/kg of OEO in grower diet significantly increased body weight gain when compared with the control group (P 0.05), populations of cecal Escherichia coli were significantly lower in 300 and 600 mg/kg OEO supplemented groups in comparison with the control and 1200 mg/kg OEO supplemented groups (P 0.05), antioxidant activity of serum was higher in OEO supplemented groups. In conclusion, OEO exerted growth promoting effects and also displayed potent antibacterial effects against cecal E. coli .