Heat Stress
The high temperatures and humidity can cause heat stress in animals, just like it does in people. Yes, I understand that summer is dwindling down. However, I find this topic extremely important. Not only could the weather spike up when you least expect it, but I feel as though this could be helpful in your preparations for next summer.
There are a few different variables that determine the level of heat stress: high humidity and low wind speed as well as the animal’s activity, body condition, coat, color, and disposition. Therefore, it is the producer’s job to pay close attention to the weather and their animals.
Weather
When looking at the weather, do not just focus on the temperature. You also need to take into account humidity, wind, and solar radiation; which is best determined by an index. The index that is most commonly used is the same one used for humans, which is also the same one reported on TV stations and the radio during the summer. This index has a threshold that is very close to the old livestock temperature-humidity index.
| Heat Index above 105o | Heat Index above 110 | Heat Index above 115o | Heat Index above 120o |
| · Still stressful for the animal
· Will be able to tolerate if the outside wind speed is at least 10 mph. · Show animals will need shade and/or moving air via fans. |
· Stressful regardless of wind speed
· Show animals should be in the shade with fan · Have plenty of access to water · All livestock shows should be completed by noon, if possible · Loading of livestock should also be completed by noon |
· Avoid moving or handling market ready animals, if possible
· Livestock show rings should be shaded with fans and misters; the show should also be postponed due to excessive heat |
· No activity should occur for animal or human
· May cause serious health risks or even death |
Animals
Signs:
- Panting
- Increased water intake
- Loss of Appetite
- Lethargy
- Increased salivation
- Increased respiration rate
- Increased water intake
- Unconsciousness
Effects:
- Reduced weight gain
- Poor breeding efficiency
- Lower milk production
- Increased disease susceptibility
- Changes in behavior
- And even death
Prevention:
- There must be easy access to cool, clean water at all times.
- Animals need to be provided suitable shelter. Materials such as corrugated iron, timber, aluminum, or galvanized steel are ideal for shelters because they are very good at reflecting radiative rays from the sun.
- Please make sure your shelter has proper ventilation by providing fans or windows.
- Besides a constructed shelter, trees also provide ample protection from the sun.
- Along with having water available, provide hoses and sprinklers. The water droplet size should be large. Be cautious of misting (small droplets) as it may only add to the humidity and moisture in the air.
- DO NOT handle your animals unless absolutely necessary. Moving, transporting, or handling animals during hot weather will only add to the stress and could increase the chance of the risks listed above.
It is the producer’s job to monitor all weather conditions as well as animal behavior. Be cautious of warm days followed by warm nights-there may not be enough time for your livestock to cool down completely. When checking the weather it is more reliable to use AccuWeather rather than the app on your phone: https://www.accuweather.com/en/us/rensselaer-ny/12144/weather-forecast/339749 . Also, pay slightly more attention to your animals that are young, darkly colored, or have recently been ill as they have a higher risk of heat stress. If you would like more species specific information check out the following link: http://agriculture.vic.gov.au/agriculture/animal-health-and-welfare/animal-health/animals-in-hot-conditions/caring-for-animals-during-extreme-heat
Stay Cool,
-Kayela
Sources:
https://www.extension.iastate.edu/sites/www.extension.iastate.edu/files/4h/AnWelfareHeatStress.pdf
https://www.beefmagazine.com/health/heat-stress-livestock
