PINE BLUFF, Ark. – As the summer temperatures rise, livestock producers should make sure their animals have a way to keep cool, says Dr. David Fernandez, Extension livestock specialist and interim assistant dean of academic programs for the University of Arkansas at Pine Bluff School of Agriculture, Fisheries and Human Sciences. Overheating can cause animals to lose their appetites, become fatigued, and in extreme cases, die.

Dr. Fernandez said animals gain heat through two processes – conduction and radiation. Conduction occurs when heat is transferred from an object to an animal, such as when an animal is warmed as it lies on hot ground. Radiation, on the other hand, occurs when sunlight strikes an animal’s body and the resulting heat is absorbed.

Darker colored animals absorb more heat through radiation than light colored animals, he said. Some animals have light colored hair but dark colored skin, so they can become warm faster than one might expect.

“Animals also generate heat internally as they metabolize feed and go about their daily movements,” Dr. Fernandez said. “Between internal heat generation and external warming on hot days, an animal can overheat.”

Overheating causes animals to stop eating and increases their heart and respiration rate. Severely affected animals can become weak and unable to stand. Extremely elevated temperatures – over 107 degrees F – can result in the animal’s death.

Other side effects of heat stress are impaired weight gains and reproductive failure, especially in males. Overheating can also suppress the immune system, resulting in outbreaks of diseases such as pneumonia during especially hot weather.

To reduce the chances of their livestock overheating, producers should understand how livestock keep cool naturally.

“Animals naturally keep cool in a variety of ways,” Dr. Fernandez said. “They reduce their activity levels and seek shade, where they can often be found lying down. They may pant, or in the case of horses and Brahman cattle, sweat.”

To ensure the safety of their livestock, Dr. Fernandez recommends producer use the following tips:

Keep drinking water cool. Since drinking cool water helps livestock maintain a healthy temperature, producers should try to guarantee a source of cool water for their animals. Simply erecting a shade over a water trough or tank can make the water quite cool.

Provide shady areas. Shade reduces an animal’s heating from radiation and allows heat to dissipate from its body. Shade can come from trees in the pasture or from portable homemade structures that animals can rest under.

Avoid working animals in the hottest part of the day. Increased activity can overheat their already hot bodies and cause heat stress.

Only shear sheep in the spring. This ensures the wool has a chance to grow a bit. Sheep with about an inch of wool are cooler than freshly shorn sheep, and they are less likely to get sunburned.

“Livestock do not need to live in airconditioned comfort – they are well-adapted to both the heat and cold of Arkansas,” Dr. Ferndandez said. “Providing shade and cool water, however, can help reduce productivity losses and make your livestock more comfortable during hot summer weather.”

For more information on this or other livestock topics contact Dr. Fernandez at (870) 575-7214 or fernandezd@uapb.edu.