Influence of functional nutrients on poultry performance and health by reducing stress response under environmental stress

Abstract

In animal production, 'stress' refers to environmental conditions that negatively impact an animal's well-being. Livestock, particularly poultry, are frequently exposed to a range of environmental stressors such as heat, high stocking density, transportation and nutritional deficiencies, all of which can impair growth performance, immune function and overall welfare. Rather than focusing solely on identifying stressors, recent research has emphasised the role of functional nutrients in alleviating the adverse effects of stress. Previous studies have shown that various functional nutrients, including amino acids (threonine, tryptophan and glycine), vitamins (A, C and E) and minerals (chromium, selenium and zinc), can support antioxidant defence, improve gut integrity and enhance immune responses in stressed poultry. These nutrients offer targeted physiological benefits that may help sustain performance and health under stressful conditions. The current review summarises evidence on the physiological impacts of stress in poultry and evaluates the effectiveness of functional nutrients in mitigating those impacts. These functional nutrients collectively contribute to improving stress tolerance, metabolic balance and overall productivity in poultry, providing practical nutritional strategies that can be applied in commercial production environments.