Here's why:
* They pant to cool down. Cows mainly rely on panting to regulate their body temperature. Panting helps them lose heat by evaporating moisture from their lungs and respiratory system.
* They have a limited number of sweat glands. Cows have very few sweat glands compared to humans. These glands are mainly located on their noses and hooves.
* They rely on other methods. To cool down, cows also seek shade, wallow in mud or water, and adjust their behavior, like standing still in the heat of the day.
So, while you might see a cow panting heavily on a hot day, that's their way of sweating, even if it doesn't look like it!