Heat Stress in Livestock
What is Heat Stress?
Heat stress occurs when an animal’s body is exposed to high external temperatures, causing its internal temperature to rise to a critical level. This enables the animal to regulate its internal temperature naturally, which can lead to critical illness or death.
Identifying Heat Stress
There are many signs of heat stress that you can look for in your animals. Some general signs include:- Panting
- Profuse sweating
- Shaking
- Increased respiration rate
- Increased water intake
- Loss of appetite
- Lethargy
- Increased salivation
- Unconsciousness
- Dark Coat Color
- Older Age
- Breeds originating from cooler regions
- Small Animals
- Animals lower in herd ranking
- Dehydrated Animals
- Traveling Animals
- Working Animals
Treating Heat StressIf your animals are showing signs of heat stress, the following actions can be taken to cool them down:
- SHADE: Move any stressed animals to the shade immediately, preferably to an area with a breeze. If animals are too stressed to move, provide shade where they are using pop-up tents, shade cloth, or other similar materials.
- COOL CLEAN WATER TO DRINK: Offer plenty of cool, clean water, but encourage animals to drink small amounts often. Over drinking can lead to colic, causing more medical issues.
- ELECTROLYTES & SUPPLEMENTS: Offer animals cool water with species-specific electrolytes or a basic electrolyte mix (Clear Pedialyte). Ruminants and small ruminants can be given B-Complex to aid with the effects of stress on the rumen and microbes.
- COOL CLEAN WATER EXTERNALLY: Animals can be sprayed with cool water, especially on the legs and feet, or can be stood or placed in water (Ensure animal can hold head above water by themselves). Use sprinklers or hoses for cattle, pigs, and horses. Utilize wet towels if running water is not available (make sure a breeze is present). Dogs and small animals can be placed in buckets or a trough of cool water. Poultry should not be wet down unless there is a breeze to aid the cooling process.
- AIR MOVEMENT: Increase air movement around the animals. This can be achieved through the use of fans, ventilation, or wind movement. Ensure that animals have ample room to lie down and that there is adequate air movement around them.
WHEN TO MAKE THE CALL
If the animal shows no signs of improvement within 30 minutes after the aid was given, contact your local veterinarian for assistance.
MANAGEMENT
Managing animals in high temperatures requires planning. Keep an eye on upcoming weather forecasts and develop a plan for days of high to extreme temperatures (80 degrees or more). Ensure that animals will have sufficient shade and water on those very hot days. Heat load can be worsened by high overnight temperatures, where the heat load of the day cannot be removed before the following hot day. This means there is an increased risk of heat stress when consecutive hot days and nights occur. This can become critical when nighttime temperatures are above 75°F.
It is the responsibility of livestock owners or managers to be well-prepared for heat events. This includes:- Forward planning of farm infrastructure to provide shaded areas with good ventilation.
- Move animals to pasture with shelter or tree coverage
- Provide ample cool watering sources, such as large water troughs, to ensure all animals have access.
- Avoid working animals during midday and on hot days.
- Avoid transporting animals during the day.
- Transport animals in the early morning or late evening.
- Check animals regularly throughout hot days for signs of stress.
Michelle South – Area Extension Agent, Agriculture – Livestock (Avery and Mitchell Counties) at 828-387-5748 or email at mcsouth@ncsu.edu.
