Adverse effects of heat stress during summer on broiler chickens production and antioxidant mitigating effects

Broiler chicken meat is a good source of protein consumed universally, and is one of the most commonly farmed species in world. In addition to providing food, poultry non-edible byproducts also have value. A major advantage of broiler chicken production is their short production cycle, which results in a greater rate of production in comparison to other species. However, as with any production system, there are constraints in broiler production with one of the most pressing being energy requirements to keep the birds warm as chicks and cool later in the growth cycle, as a result of the cost needing mechanical heating and cooling. While this is feasible in more advanced economies, this is not readily affordable in developing economies. As a result, farmers rely on natural ventilation to cool the rearing houses, which generally becoming excessively warm with the resultant heat stress on the birds. Since little can be done without resorting to mechanical ventilation and cooling, exploring the use of other means to reduce heat stress is needed. For this review, we cover the various factors that induce heat stress, the physiological and behavioral responses of broiler chickens to heat stress. We also look at mitigating the adverse effect of heat stress through the use of antioxidants which possess either an anti-stress and/or antioxidant effects.