Strategies to combat heat stress in poultry production- A review

Abstract

The effects of heat stress caused by high ambient temperature continues to be a global concern in broiler chicken production. Heat stress causes metabolic changes inducing oxidative stress, immune dysregulation, gut dysbiosis and acid-base imbalance that subsequently affect the overall performance and health status of broiler chickens. These negative effects induced by heat stress reduce feed intake, feed efficiency, body weight, meat quality, cause high mortality and eventually resulting to economic losses. Several intervention strategies have been reported by researchers. Good management practices such as: proper house design, enough ventilation, low stocking density, optimum temperature, and provision of fresh and clean cold water during rearing are key to manage heat stress in poultry houses. Nutritional interventions such as supplementation of a balance diet, vitamins, minerals, feed restriction, dietary supplementation of pre-and/probiotics in-feed and or in-water have been proposed to reduce the adverse effects of heat stress. Early heat conditioning and thermal manipulation also provides birds thermotolerance to heat stress. The most recent intervention strategy to ameliorate heat stress in poultry is the early perinatal programming using the in ovo technology to administer bioactive substances in ovo. Such an approach seems to be particularly justified in broilers, because chick embryo development (21 days) equals the half of the post-hatch life span (42 days) of the chickens. As such, this strategy is expected to be more productive to counteract and mitigate the negative effects in poultry. Therefore, this review article discusses the different management and nutritional strategies to mitigate the detrimental effects of heat stress in poultry. KEYWORDS: bioactive substance, high temperature, poultry, production