Mechanisms underlying the Effects of Heat Stress on Intestinal Integrity, Inflammation, and Microbiota in Chickens

Abstract

Poultry meat and egg production benefits from a smaller carbon footprint, as well as feed and water consumption, per unit of product, than other protein sources. Therefore, maintaining a sustainable production of poultry meat is important to meet the increasing global demand for this staple. Heat stress experienced during the summer season or in tropical/subtropical areas negatively affects the productivity and health of chickens. Crucially, its impact is predicted to grow with the acceleration of global warming. Heat stress affects the physiology, metabolism, and immune response of chickens, causing electrolyte imbalance, oxidative stress, endocrine disorders, inflammation, and immunosuppression. These changes do not occur independently, pointing to a systemic mechanism. Recently, intestinal homeostasis has been identified as an important contributor to nutrient absorption and the progression of systemic inflammation. Its mechanism of action is thought to involve neuroendocrine signaling, antioxidant response, the presence of oxidants in the diet, and microbiota composition. The present review focuses on the effect of heat stress on intestinal dysfunction in chickens and the underlying causative factors. Understanding these mechanisms will direct the design of strategies to mitigate the negative effect of heat stress, while benefiting both animal health and sustainable poultry production.

Combined Effects of Cyclic Heat Stress, Dietary Induced Oxidative Stress and Different Levels of Antioxidant on Gut Fermentation Activity and Mucosal Morphology in Broiler Chickens

“…The content of the other SCFAs studied in the small intestine was minimal. Nevertheless, there is growing evidence that HS is a relevant environmental factor that can significantly affect gut viability and functioning and compromise animal welfare [84]. However, the main nutritional strategies investigated to date to mitigate the effects of HS include fortification with antioxidants in the diet [85,86].…”

Appropriate Genetic Approaches for Heat Tolerance and Maintaining Good Productivity in Tropical Poultry Production: A Review

“…During heat stress conditions, the decrease of plasma T3 and T4 concentrations was observed to decrease metabolic heat production [80]. Mean-while, releasing GC hormones, such as corticosterone, during heat stress conditions resulted in increased fat accumulation [81]. Therefore, the heat stress conditions lead to decreased and increased protein content and fat deposition in chicken meat muscles, declining meat quality [82].…”