Most of us look at today’s temperature or THI and think we know how much heat stress our cows are under.
The cows know better.
They feel the heat they couldn’t get rid of yesterday… and the day before.
During our commercial trial in the Middle East, an accidental event proved just how real this is — and the results were impossible to ignore.
What Happened When Cooling Was Interrupted
On June 30 at 3:00 PM, evaporative cooling on the Core Cool System was accidentally shut off. High-speed fans kept running at full power, but the water was off until 6:00 AM the next morning.
Fifteen hours without evaporative cooling.
Here’s what that did to Group 5:
Group 5 had been handling the heat relatively well. Then HBR jumped from 101 to 146 minutes the next day and stayed high at 132 the day after. It took nearly two full days for breathing rates to return to normal.
The weather didn’t suddenly get worse. The only thing that changed was the cows’ ability to remove heat.
That’s the part that should make every dairy manager pause.
Even with maximum airflow still running, losing evaporative cooling created a clear, measurable spike in stress — and recovery took much longer than the interruption itself.
The Conditions Were Already Tough
Peak THI hit 80.9. Cows had zero hours below THI 68 that week. Nighttime cooling was already limited. Taking away evaporative cooling under those conditions showed exactly how much it was contributing — even when humidity was high.
The Real Question for Your Farm
If a 15-hour gap can affect cows for nearly 48 hours, what is happening on farms where cooling is marginal night after night all summer long?
That slow accumulation of heat load is where many operations quietly lose production, fertility, and cow comfort.
Cool the Cow. Not the Barn.
The best cooling strategies don’t just react to hot afternoons. They help prevent heat from building up in the first place.
Ready to see what better cooling could do for your herd?
If you’re tired of watching milk production drop when the heat hits, or you want to know whether your current system is leaving money on the table, let’s talk.
We would love the opportunity to discuss your operation and how your cows are currently handling heat stress, review your current cooling strategy, and explore what value a Core Cool System could bring to your farm.
Call us at +1-330-717-8852 or email info@corecoolsystems.com.
No pressure, let's discuss your specific conditions and goals.
The next heat wave is coming. Together, let's make sure your cows are ready.