The hot days of the summer months can be the most uncomfortable of the year for livestock in Louisiana, but keeping alert for warning signals and taking precautions can lessen the stress on animals.

This stress causes general discomfort, decline in animal performance, and can even cause death. Heat stress is defined as any combination of temperature, humidity, radiation, and wind producing conditions higher than the animal's thermal neutral zone. Take these measures to treat heat stress of livestock:

SHADE
Heat from the sun is a major culprit in overstressed animals. If animals are kept outside, provide shade during hot weather. Keep the cattle out of the sun from about 9 a.m. - 4 p.m. Light haired animals (Charolais, blonde Simmentals, and crosses) can even get sunburn.

Angus and black animals can be easily overheated by radiant heat because the black absorbs more of the sun's radiant heat. Either open-sided sheds, trees, or other shade can reduce the radiant heat by as much as 40 percent.

Swine may have sunburn during hot, sunny weather. Try to keep them out of the sun. Sun shades can cut the radiant heat load by as much as 40 percent.

Pasture wallows are also effective for sunburn protection and wet skin cooling. Turn the cows around outside at night to cool them and cool the barn.

Since animals cool themselves primarily through breathing, barns tend to get warm and humid quickly.

VENTILATION
Good ventilation is necessary to maintain livestock health during hot and humid weather. Have the shade in a location where there is a breeze and ensure that the sides are open for good ventilation.

The shed roofs should be at least 10 feet tall. If the peak is open, it will allow the hotter air to escape. If the roof is insulated, it will help reduce the radiant heat. Without proper air exchanges and airflow distribution within livestock buildings and shaded areas, heat and moisture accumulate and the animals will be stressed.

This stress affects animal production. If necessary, you may need to contact a ventilation specialist to inspect and update your system. Your county extension office also may be able to help you.

WATER
Clean, fresh, and preferably cool drinking water in good supply is vital to animals in hot humid weather. Animals cool themselves by panting and some sweating. In panting, there is water loss from the lungs. There is also cooling accomplished by water evaporation from the skin.

Since beef cattle and pigs do not sweat, in extreme heat, they must increase respiration in order to cool themselves. They may need to be sprayed with water to keep them cool.

Check the water troughs daily to make sure there are no supply problems. Make sure there is enough space for everyone to drink, but not so much that the water grows warm and stale throughout the day. You want the water supply to turn over rapidly and be cool and fresh. Adequate water supply is needed to replace water loss during the cooling process.

BE WATCHFUL
Use the temperature humidity index as a guide to heat stress. Listen to local or regional weather reports for the temperature humidity index (THI) for your area. Some levels of concern include:

• Above 75 THI - Heat stress on high-producing cows begins to decrease feed intake and lower milk production.
• Above 80 THI - Severe heat stress may occur for cows on pasture.
• Shade and adequate ventilation are essential to minimize milk loss.
• Above 83-85 THI - Danger of fatal heat stress occurs.

# # #