Comprehensive impacts of black elderberry ( <i>Sambucus nigra L.</i> ) extract on mitigating acute heat stress, augmenting antioxidant defenses, and enhancing broiler chicken health and meat quality

Poultry genotypes’ low heat tolerance affects birds’ health, which results in major economic losses and calls for an immediate, consumer-friendly dietary plan. This study assessed black elderberry extract (BE) on 120-Cobb chickens, 35-days old, to mitigate the adverse-effects of acute heat stress on clinical and pathological parameters, antioxidant status, and meat quality. Birds were divided into four-groups: NEG: maintained at thermoneutral temperature (24 ± 1°C); 2) BE: administered 0.15 g/L BE extract for 12-h while kept at 24 ± 1°C; HSBE: maintained at 38 ± 1°C for 6-h and treated with BE extract (0.15 g/L); HS: maintained at 38 ± 1°C for 6-h. BE supplementation under heat stress significantly mitigated these effects, reducing rectal temperature and droppings moisture (p < 0.05), lowering both macroscopic and histological lesion severity at 3 and 12 h (p < 0.05), and improving meat quality traits—lower cooking and thawing losses, enhanced water-holding capacity, and better tenderness – while also diminished muscle malondialdehyde concentration, and elevated levels of polyunsaturated fatty acids (PUFA) and omega-3 PUFA, particularly alpha-linolenic acid (p < 0.05). The results suggest that the use of BE extract in the water of broiler chickens during periods of heat stress is beneficial, and further research on heat stress-reducing efficacy of BE is needed.