Effect of Oregano (Origanum vulgare) extract on performance in broiler chickens

This experiment was conducted to investigate the effects of different levels of oregano extract (OE) o performance in broiler chickens. A total of 360 male chicks in a completely randomized design with 5 treatments, 4 replicates of 16 birds were distributed and reared under experimental same conditions. During experimental period (1 d until end period), drinking water of the control group had no any additive while antibiotic (0.0125 % Erythromycin), 1.5, 3 or 4.5% OE were added respectively to other 4 experimental groups. The findings indicated that the use of OE affected significantly feed intake, body weight gain and feed conversion ratio in broiler chickens. In 11-24 d period, the highest feed intake was obtained in groups fed 4.5% OE or antibiotic. Also in this period, feeding 3 or 4.5% OE or antibiotic to broilers caused the significant highest weight gain (P<0.05). in overall period, using 4.5% OE caused significantly the highest weight gain and also, 3 and 4.5% OE significantly decreased feed conversion ratio in broiler chickens. In conclusion, using OE especially in level of 4.5% in broiler drinking water has beneficial effects on performance parameters and therefore can be applied as a suitable replacement for antibiotic in broiler chickens.