During the summer months, cow cooling becomes fundamental to animal care. That justifies the many research trials, articles, and trainings that surround heat stress. As we have learned more about how cows handle the heat and convey their need for cooling, the industry has honed in on the best ways to mitigate these summer conditions.
In a recent Buckeye Dairy News article, Assistant Professor Grazyn Tresoldi reminded readers that heat stress can be addressed with environmental adaptations. “The solution to mitigate high heat load is clear and consistent across climates: shade, soakers, and fans,” she explained. “Combining fans to increase convective heat loss with misters or soakers to promote evaporative cooling is the most effective way to cool cattle.”
Speaking specifically to evaporative cooling, Tresoldi recommended placing soakers and fans at the feedbunk and setting them to turn on before body temperatures begin to rise. She reminded readers that cows begin to experience heat stress around 65 temperature-humidity index (THI).
“Wetting cattle for 30 seconds (enough to soak their coat) every four to five minutes and using fans that deliver a wind speed of 9 to 10 feet/second at the animal level is ideal,” The Ohio State assistant professor detailed. “Using soakers that deliver larger droplets is preferred.”
Specifically, Tresoldi recommended nozzles that deliver 1.3 gallons per minute. That level has resulted in an extra 3 pounds of milk per day per cow. This being true, she shared that 0.9 gallon per minute nozzles also effectively cool cattle.
“While lower flow rate soakers (e.g., 0.4 gallon per minute) can abate heat, the fine droplets can drift to the bunk and affect feed quality,” Tresoldi explained.
If cooling in the cattle housing structure isn’t an option, she recommended cooling in the waiting areas near the milking parlor. “Research I have conducted in the past showed that a 45-minute cooling session reduced body temperature for 50 to 75 minutes, depending on the volume of water applied,” Tresoldi further detailed.
While it’s easy to focus on the animals producing milk, dry cows, heifers, and calves deserve focus as well. Without going into detail, Tresoldi recommended shade and airflow as a minimum.
“It’s crucial to offer additional overhead shade and enhanced airflow by elevating hutches or adding openings to improve air exchange,” she wrote specifically about calf cooling.
No matter the age or stage of lactation of the cattle on your farm, keep these cooling tips in mind as you face the warm temperatures of summer.
