Beneficial effect of polyherbal feed additives on growth performance carcase characteristics and cortisol levels of broiler chickens

This study investigates the effects of polyherbal feed additives (PHF) under stress caused by stocking density on growth performance, carcase characteristics, and cortisol concentration of broilers. A total of 320 one-day-old Ross 308 broilers were randomly assigned to six treatments (four replicates each, 1.00 m2 floor space/pen). Treatments followed a completely randomised design based on stocking density and levels of PHF (Phytocee®) supplementation: Treatments included a control diet at normal (10 birds/pen; ConND) and high (15 birds/pen; ConHD) densities, and PHF-supplemented diets at 300 mg/kg (10 birds/pen; PHY300ND) and 300, 400, or 500 mg/kg (15 birds/pen; PHY300HD, PHY400HD, PHY500HD). Growth performance was assessed during days 0–10, 11–25, and 26–35; cortisol levels were measured on days 28 and 35, and carcase traits were evaluated at 35 days of age. Initial body weights did not differ among groups Birds in the PHY300ND group exhibited the highest final body weight and average daily gain during days 11–35. Supplemented groups showed improved feed conversion ratios (p < 0.01). Economic efficiency, including reduced feed cost per bird and increased net profit, was significantly enhanced (p < 0.01). On day 28, PHY500HD birds had lower cortisol levels than control and other high-density groups, though this effect was not observed on day 35. Overall, PHY300ND improved growth and profitability, while PHY500HD reduced stress indicators under high-density conditions. These results suggest that PHF may enhance productivity and welfare in broilers, warranting further investigation into optimal dosing and long-term benefits.