Effects of brown seaweed products on growth performance, plasma biochemistry, immune response, and antioxidant capacity of broiler chickens challenged with heat stress

This study explored the impact of brown seaweed (Ascophyllum nodosum) supplementation on growth performance, physiological responses, and health parameters in broilers exposed to heat stress. Birds receiving seaweed - either as a feed inclusion or water extract - showed improved feed intake, body weight gain, and overall performance compared to controls, under both thermoneutral and heat stress conditions. Heat stress negatively affected feed intake, altered blood biochemistry, increased immune activation, and reduced antioxidant enzyme activity, indicating physiological strain. Seaweed supplementation helped mitigate some of these effects by improving plasma enzyme profiles related to liver function and digestion, and by reducing markers associated with metabolic stress. While antioxidant enzyme activity and immune organ weights were not significantly enhanced, the findings suggest that brown seaweed supports resilience to heat stress primarily through improvements in metabolic and physiological stability rather than direct immune or antioxidant modulation.