Driven by the rising demand for animal protein, the use of synthetic antibiotics in broiler diets to accelerate growth has become a public health concern due to the potential spread of antibiotic-resistant bacteria. This study investigated the effectiveness of Oregano (Origanum vulgare L.) leaf meal (OLM) as a potential antibiotic alternative in enhancing broiler chicken growth performance. A completely randomized design was employed with 125 Cobb broiler chickens and five treatment groups. The diets included antibiotics (0.0025%) in T1, and groups supplemented with varying OLM levels T2 (1%), T3 (3%), T4 (5%), and T5 receiving no antibiotics and OLM. OLM demonstrated a significant positive impact on growth performance (P < 0.05), with birds in the 3% OLM group achieving the highest live weight (1185.40 grams) and average daily gain (38.01 grams) by day 28. Notably, no significant differences were observed in feed conversion ratio, and groups with 3% and 5% OLM supplementation displayed no mortality. Additionally, OLM did not induce gut inflammation or the presence of undigested particles in the colon. Interestingly, the 3% OLM group also exhibited a significantly higher dressing percentage (68%), suggesting improved carcass yield. These findings indicate that OLM, rich in phenolic and flavonoid compounds, has the potential to be a safe and effective alternative to antibiotic growth promoters in broiler chickens, warranting further investigation into the mechanisms underlying its beneficial effects.
Keywords | Origanum vulgare, Antimicrobial alternatives, Phenolic compounds, Flavonoid compounds, Gut health, Mortality