Comparative Effects of Non-Antibiotic Growth Promoters and Antibiotics on the Performance of Broiler Chickens

This study evaluated the effects of non-antibiotic growth promoters and an antibiotic on the performance of broiler chickens. A total of 150-day-old Lohmann Meat broiler chicks were randomly assigned to five dietary treatments with three replicates per treatment and 10 birds per replicate for 28 days. The treatments were: basal diet without supplementation (T₀), phytogenic blend with organic acids at 100 g/ton (T₁), lysozyme at 500 g/ton (T₂), cinnamon at 500 g/ton (T₃), and bacitracin at 500 g/ton (T₄). Dietary treatments significantly influenced feed intake, body weight gain, feed conversion ratio, and flock uniformity (P < 0.05). Birds fed the phytogenic blend, lysozyme, and cinnamon showed higher feed intake and body weight gain than the control and bacitracin groups. Feed conversion ratio improved in all supplemented groups, with the lowest value observed in the cinnamon group, followed by the phytogenic blend and lysozyme. Weekly results further showed significant treatment effects on body weight gain and feed conversion ratio across different growth stages, particularly in the later phase. Bacitracin supplementation did not confer comparable performance benefits and was associated with reduced overall performance. The findings indicate that phytogenic additives, essential oils, organic acids, and lysozyme can enhance broiler growth performance and feed efficiency, and may serve as effective alternatives to antibiotic growth promoters in broiler production. Res. Agric. Livest. Fish. Vol. 13, No. 1, April 2026: 133-147