Specifically, the brain triggers a response that causes our pores to release water molecules that then pool on the surface of our skin. These water molecules are in constant motion and the relative speed of their motion is directly related to their temperature.
Sweat is relatively hot water and so the water molecules that form on the surface of our skin are ones that are moving rapidly compared to the external environment. In fact, these water molecules are moving so quickly that they bump into one another and some are propelled off the surface of the skin in the form of water vapor. When this happens, the evaporating water molecules literally carry their heat with them into the air leaving the skin cooler.
Chickens also use evaporative cooling to rid their bodies of heat, but the evaporative cooling is accomplished in a different way. Chickens lack sweat glands, so they drive off excess heat by evaporating water located on the surface tissue of their lungs.
Anyone who has ever owned a dog will immediately recognize how this is accomplished because dogs and chickens both cool themselves by panting.
Air is drawn int the chickens lungs where the heat exchange is accomplished and then the chicken exhales the warm moist air, thereby lowering it's body temperature. Check out the below video of one very hot chicken.
Chickens & Heat Stress
A chicken's body temperature is normally around 107 degrees Fahrenheit. A chicken can usually regulate it's body temperature effectively as long as the outdoor temperature is ten degrees below body temperature.
However, once the outside temperature climbs above 95 degrees, a chicken runs the risk of heat stress. The risk is even higher on humid days because evaporative cooling becomes less effective. This is because humid air is so saturated with water that it is becomes difficult for the chicken to transfer water within its lungs to the air.
In other words, panting becomes less effective when the air is wet. (By the way, the same is true for humans and our ability to sweat. This is why a 95 degree day in a humid environment like Miami is so much more uncomfortable than a 95 degree day in a dry environment like Phoenix)
Here are the warning signs that your chickens are experiencing heat stress:
- Egg laying stops
- Labored breathing
- Outstretched legs and wings
Preventing Heat Stress & Dehydration
- To help prevent heat stress and dehydration, make sure you give your chickens plenty of cool water. This is your first and most important line of defence.
- Supplement your chickens normal dry feed diet with , moist foods. Tuna fish, green vegetables and fruits etc. A number of chicken owners I know will actually give their chickens a chilled watermelon on very hot days.
- Add electrolytes to the water - Electrolytes are minerals that help a chicken replace and retain fluids. You can buy premade electrolytes for chickens from your local feed store or mix your own. In her book, The Chicken Health Handbook, Gail Damerow provides the following recipe for a home brew electrolyte solution: 2 quarts water, 1/2 teaspoon potassium chloride (salt substitute), 1/2 teaspoon backing soda, 1 teaspoon table salt.
|Chickens Driking from The BriteTap Chicken Waterer|
Posting sponsored by ChickenWaterer.com, makers of the BriteTap poultry nipple waterer. The BriteTap chicken waterer shields water from dirt and poop. The water stays clean and there are no messy pans for you to wash out.