Assessment of combined effects of thermal acclimation, probiotics, and Bunium bulbocastanum essential oil on performance, carcass traits, and meat quality in heat-stressed broilers

Heat stress poses a significant challenge to poultry production, negatively impacting broiler growth performance, feed efficiency, and meat quality. This study investigated the synergistic effects of early-age thermotolerance acclimation, probiotics, and Bunium bulbocastanum (BB) essential oil supplementation on broiler performance, carcass traits, and meat quality under heat stress conditions. Eighty Arbor Acres broiler chicks were randomly assigned to four experimental groups: Control (CON), Thermotolerance Acclimation (TA), Probiotic Supplementation (PRO), and Essential Oil Supplementation (BBEO). The PRO and BBEO groups demonstrated notable improvements, with the PRO group achieving the highest final body weight (2.36 ± 0.04 kg) and an optimized feed conversion ratio (FCR, 1.55 ± 0.02). Carcass yield was significantly enhanced in the PRO group (76.2 ± 1.4%) compared to the control (72.3 ± 1.7%). Meat quality parameters improved significantly in the BBEO group, with superior water-holding capacity (WHC, 78.4 ± 1.2%), lower cooking loss (15.3 ± 0.5%), and reduced lipid oxidation (MDA, 0.45 ± 0.02 mg/kg), demonstrating its strong antioxidant potential. Nutritional analysis revealed elevated crude protein content in the BBEO (23.1 ± 0.4%) and PRO (22.8 ± 0.5%) groups, along with reduced fat content. Additionally, the BBEO group exhibited the highest polyunsaturated fatty acid (PUFA) content (24.3 ± 1.1%), enhancing the nutritional value of the meat. These findings underscore the potential of probiotics and BB essential oil supplementation to mitigate heat stress effects and improve broiler productivity and meat quality.