Preventing Heat Stress

Heat stress is created when livestock can’t expel enough heat to maintain their core body temperature for optimal production and health.

The THI (temperature humidity index) is a number that combines humidity and temperature to correlate with the amount of heat stress an animal experiences.

New research from the University of Arizona (Collier et al) suggests that cows experience a milk loss starting at a THI of 68.

• Professor Jodie Pennington at the University of Arkansas recommends testing 10 cows’ rectal temperatures and if 7 are 103 °F or above, they are experiencing heat stress

• Respiratory Rate >100 breaths/min

• Excessive salivation

• Open mouth breathing

• If the dry matter intake decreases by 10% the animal is under high stress

• If the dry matter intake decreases by 25% the animal is under severe stress

• Keep cows comfortable and cool

• Supply adequate, fresh, clean water at all times

• Provide shade, fans, misters (in lower humidity areas) and coolers

• Make sure fans are provided by sprinklers for proper evaporative cooling

• Deliver feed more frequently and push up feed more often

• Feed during cooler times of the day

Shop these recommended products to aid your dairy cows during the heat of summer.