Physiological mechanisms by which chickens adjust rising temperature

In animal system, after feeding heat produced during fermentation in the gastrointestinal tract and also during processing and use of food nutrients in the body. This heat is not wasted when the temperature is below the critical temperature, as it is used to keep the body warm. But under high environmental temperature, chickens have a problem in getting rid of the surplus heat. Therefore, they will eat less to avoid increment of physiological heat.

• Due to absence of sweat glands, drinking excessive amounts of water is one way to keep their body cool.
• Since movement increase body temperatures, birds at high environmental temperature will restrict their activity.
• In a deep litter system, birds will often take a bath in their litter, which is generally cooler than their own body temperature.
• At discomfort region of temperature (above 800F), chicken open out their wings and begin to pant or mouth breathe. By doing so, birds give out large amount of moist warm air.