Oregano (Origanum vulgare L.) essential oil as a natural growth promoter in broiler chickens

Abstract

Broiler chickens were supplemented with oregano essential oil showed better early growth performance compared to those fed a standard diet or the antibiotic salinomycin. During the first 10 days, the chickens receiving oregano essential oil had a highly significantly higher feed intake (P<0.01) than the group which received 1,000 ppm. It showed the highest average daily feed intake of 26.62 g/bird, followed by the 2,000 ppm and 4,000 ppm groups, which had averaged intakes of 25.9 and 25.81 g/bird, respectively. However, the differences among the oregano-supplemented groups were not statistically significant (P > 0.05). In contrast, the control and antibiotic groups had lower feed intakes of 23.26 g/bird and 23.23 g/bird, respectively, but there were not significantly differed among the oregano-supplemented groups (P>0.05). Additionally, body weights and daily growth rates in all groups receiving oregano were similar to those in the antibiotics group and were significantly higher (P<0.01) as compared to the control group. However, no significant differences were observed among the various levels of oregano (P>0.05). Notably, during the same period, the group supplemented with 2,000 ppm of oregano essential oil exhibited a feed conversion ratio (FCR) that was statistically compared (P > 0.05) to the group receiving salinomycin. After the initial 10 days, there were not significant differed in growth performance or carcass traits across all treatment groups (P>0.05). The feed cost per kilogram of meat produced during the starter period for the 1,000 ppm oregano group was 25.76 Baht/kg, as compared to the control group at 25.96 Baht/kg and the antibiotic group at 23.85 Baht/kg. These findings suggested that oregano essential oil, particularly at 1,000 ppm, can serve as a cost-effective alternative to antibiotics for enhancing early-stage growth in broiler chickens without negatively impacting overall production costs or carcass quality.