Heat Stress in Broiler Chickens and the Effect of Dietary Polyphenols, with Special Reference to Willow (Salix spp.) Bark Supplements—A Review

Over the last decade, there has been a growing interest in use of wide range phytoadditives to counteract harmful effects heat stress poultry. Willow (Salix spp.) is tree with long history. Among various forms, willow bark an important natural source salicin, β-O-glucoside saligenin, but also polyphenols (flavonoids and condensed tannins) antioxidant, antimicrobial, anti-inflammatory activity. In light this, current review presents some literature data aiming to: (1) describe relationship between oxidative broilers, (2) present or summarize on chemical composition Salix species, (3) mechanisms action heat-stressed (4) different biological extract species experimental models.