Beat the Heat: Managing Heat Stress in Dairy Cows
Summer’s here—and while we might enjoy the sunshine, your dairy cows definitely don’t. When the temperature spikes and humidity hangs in the air, cows start to feel the heat. Literally, and when that happens, heat stress in dairy cows can take a serious toll on their health, comfort, and milk production.
In this blog we’ll talk about what heat stress really means for your herd—and how a simple mineral like magnesium can make a big difference.
What Exactly Is a Heat Wave?
A heat wave isn’t just a hot day or two. It’s a stretch of unusually high temperatures, often paired with high humidity. For cows, that’s a recipe for stress. Unlike us, they can’t sweat it out. Instead, they pant, drink more water, and eat less. Not ideal when you’re trying to keep milk flowing.
What Happens to Dairy Cows Under Heat Stress?
When cows become too hot, their bodies enter survival mode. They eat less, which means less energy for milk production. Their rumen doesn’t work as efficiently. They stand more to try to cool off, which can lead to lameness. And their immune systems take a hit, making them more vulnerable to illness.
The result? According to the U.S. Environmental Protection Agency (EPA), milk production can drop by 10–25% during periods of heat stress. That can be a big hit to your bottom line.
So, What Can You Do?
There are plenty of ways to help your cows stay cool and comfortable:
- Provide shade and airflow: Fans, misters, and shade structures go a long way.
- Keep water flowing: Make sure cows always have access to clean, cool water.
- Adjust feeding times: Offer feed during the cooler parts of the day.
- Change the ration: Boost energy density and consider adding buffers to support rumen health.
But here’s where it gets really interesting—nutrition plays a huge role in how well cows handle heat stress.
Why Magnesium Matters
When cows are hot, they lose more electrolytes and minerals—especially through increased respiration and urination. That’s where magnesium comes in.
Magnesium is a powerhouse mineral. It helps regulate muscle function (including breathing), supports energy metabolism, and keeps the rumen running smoothly. During heat stress, magnesium can help cows stay calmer, digest better, and bounce back faster.
We’re Your Magnesium Partner
At GLC Minerals, we understand the importance of keeping your herd healthy and productive—even in the heat of summer. That’s why we offer high-quality, bioavailable magnesium feed supplements specifically designed for dairy cows.
GLC’s magnesium products are easy to incorporate into your feeding program and deliver the support your cows need when the heat is on.