The Naked Neck Gene in the Domestic Chicken: A Genetic Strategy to Mitigate the Impact of Heat Stress in Poultry Production—A Review

SIMPLE SUMMARY: Temperature and humidity are environmental factors with significant impact on animals. This challenge is not exclusive to tropical countries, as climate change has a worldwide impact. Birds are particularly sensitive to environmental changes, and high temperature causes significant financial losses. Several strategies can be used to mitigate the impact of heat stress in poultry. The use of strains tolerant to high temperature may be an interesting solution. In this review, we address the major effects of heat stress in poultry and how the naked neck gene can be used to mitigate such adverse effects. ABSTRACT: The poultry sector is one of the most important food industries in the world. Poultry production generates high-value protein products (meat and eggs) that are produced efficiently without the need for large areas. In poultry production, especially in the tropics, environmental factors, such as temperature and humidity, play a major role. Heat stress (HS) causes behavioral, physical, and physiological changes in poultry, with severe financial impacts. Therefore, it is important to find strategies to minimize it. The naked neck (Na) is an autosomal, incompletely dominant gene. Compared with normal feathered birds, these animals are known for their ability to adapt, perform, and reproduce under hot and humid climate conditions. Due to the absence of feathers on the neck, these animals increase heat dissipation, alleviating adverse heat effects, especially on productive performance. Genetic improvement of heat tolerance may provide a low-cost solution, of particular interest for developing countries in the tropics. The focus of this review is to evaluate the impact of HS in poultry with a special emphasis on the advantages of using the Na gene.