Dietary inclusion of propolis and thyme enhances growth performance in broiler chickens

The rising demand for organic and residue-free poultry products has increased interest in natural feed additives as alternatives to synthetic growth promoters. This study evaluated the effects of Thymus vulgaris (thyme) and raw propolis supplementation on the growth performance of broiler chickens reared under extensive conditions. A total of 40 cross-breed day-old chicks were used in a seven-week experiment conducted in a village in the Polog region. The birds were assigned to control and treatment groups, receiving either 25 g kg-1 thyme, 3 g kg-1 propolis, or 6 g kg-1 propolis in their diets through out the trial. Body weights were recorded weekly, and statistical analyses were conducted to evaluate the effects of the treatments. No significant differences in body weight were observed during the first six weeks of fattening (p > 0.05). However, in the seventh week, broilers supplemented with 6 g kg-1 propolis exhibited a statistically significant increase in body weight compared to the control and lower-dose propolis groups (p < 0.01). These findings suggest a dose- and time-dependent response, indicating that prolonged supplementation and higher inclusion levels may be necessary to achieve measurable growth benefits. The delayed effect may be related to metabolic adaptations and improved nutrient utilization influenced by the antioxidant and immunomodulatory properties of propolis and thyme. The results support the potential of propolis and thyme as natural and effective growth promoters, particularly in sustainable and regionally adapted poultry systems where antibiotic use is restricted. This study contributes to the growing body of evidence supporting phytogenic feed additives as viable alternatives to antibiotics, addressing concerns related to antimicrobial resistance and consumer preference for natural poultry products.