Abstract

Heat stress is a factor that poultry farmers must consider amidst increasing global warming. Heat stress can cause physiological and biochemical disorders due to increased free radical production. In addition to improved management practices, nutritional interventions are beneficial in mitigating the adverse effects of heat stress on poultry. Microalgae, with their rich antioxidant, growth-promoting, immune-boosting, anti-inflammatory, and antibacterial properties, are a potential alternative to synthetic antioxidants and antibiotics commonly used in poultry production to overcoming heat stress. A narrative review of existing literature indicates that microalgae possess the potential to enhance poultry production and feed efficiency under conditions of heat stress. The enzymatic and non-enzymatic antioxidants present in microalgae collectively mitigate heat-induced oxidative stress. Additionally, the anti-inflammatory properties of microalgae aid in counteracting oxidative stress and inflammation caused by heat, thereby strengthening the immune response in poultry. Furthermore, microalgae contribute to the restoration of microbiota balance and gut structure, reduce physiological stress, and protect cells by decreasing corticosterone levels, regulating heat shock proteins (HSPs), and increasing the expression of sirtuins genes. Further investigation is required to ascertain the optimal dosage, species-specific responses, cost-effectiveness, and safety associated with the use of microalgae in poultry particularly during heat stress.

Key words: Antioxidant; Free radicals; Heat stress; Immunity; Microbiota.