Review Article : Heat stress and poultry: Adaptation to climate change, challenges and opportunities for genetic breeding in Kenya

Abstract

The Earth’s ambient climatic factors, such as temperature, humidity, solar radiation, and precipitation, vary through time and space due to climate change. Heat stress, one of the major factors affecting poultry production, is a direct result of climate change, resulting in enormous losses for the poultry sector. As a result of heat stress, several physiological changes such as suppressed immunecompetence, oxidative stress, and acid-base balance lead to reduced feed intake, feed efficiency, body weight, meat, egg quality, and sometimes mortality. Adverse effects have necessitated several adjustments in animal husbandry practices such as housing and feeding regimes to be implemented. Modifying the environment in poultry production systems can cushion exposure and compensate for losses in poultry fitness in heat-stressed environments. Some of the modifications that have been tested and shown to be successful in attenuating heat stress in poultry include shade, sprinkling cold water on their bodies, and adjusting diets to reduce metabolic heat production. The extensive genetic diversity of indigenous poultry is essential for climate change adaptation and the continuous enhancement of the genetic stock through breeding adaptive features like heat stress tolerance. The naked neck (Na) and frizzle (gene F) gene have been given attention in recent times in their role to withstand heat stress in poultry. A better understanding of indigenous poultry acclimatization to severe environments, together with methods and tools available for the selection, breeding, and matching indigenous poultry ecotypes to suitable environments, should help to minimize the effects of heat stress on indigenous poultry genetic resource growth, production, and reproduction to sustain food security.