EDEN PRAIRIE, Minn. – June 24, 2026 – Heat stress remains one of the biggest seasonal threats facing dairy producers. Heat and humidity not only make cows uncomfortable, but also threaten multiple aspects of their health and performance.
“The impacts of heat stress on a dairy farm are significant and are going to impact the bottom line,” says Daryl Kleinschmit, senior discovery researcher with Zinpro®.
While cooling systems, shade and water access are proven tools to help mitigate the effects of heat stress, nutrition also plays a role. Optimizing trace mineral nutrition can help strengthen cellular defenses, maintain gut integrity and support overall resilience.
Heat stress effects multiple health factors
One of the earliest and most visible signs of heat stress is a change in a cow’s eating routine. “If you’re looking at cows undergoing heat stress, one of the key things you might see right away is a reduction of dry matter intake,” says Dr. Kleinschmit. “That reduction results in a decrease in milk yield.”
According to Kleinschmit, other consequences of heat stress include compromising of the immune system, increases in somatic cell count, reduction in reproductive efficiency and, in some cases, lameness.
“When cows are hot, they need to dissipate more heat, so they stand more,” says Kleinschmit. These extended periods of standing can lead to sole ulcers, which sometimes don’t appear until months down the road. Besides the potential for hoof problems, heat stress can also impact the gut.
Maintaining gut integrity
Often overlooked, consequences of heat stress occur within the gastrointestinal tract. When blood flow is redirected to peripheral tissues to help dissipate the heat, it reduces nutrient and oxygen delivery to the gut. This can compromise epithelial integrity within the digestive tract, leading to what is commonly referred to as “leaky gut.”
When this happens, inflammatory compounds and toxins can more easily cross into circulation, increasing systemic inflammation and further draining energy away from productive functions.
Maintaining strong epithelial barriers is an important part of heat stress management. Trace minerals, especially zinc, play an important role in supporting this defensive system.
Zinc as a tool to help protect the gut
Used as a dietary supplement in dairy cattle for many years, zinc has proven itself to be a powerful addition to a cow’s diet.
“Besides managing the environment, producers should take advantage of quality trace minerals to help manage cows’ overall ability to withstand heat stress,” says Dr. Kleinschmit. “Zinc, in particular, plays a very important role in maintaining the epithelial tissue in the gut lining. It also plays a role in maintaining integrity in the mammary gland, reproductive tissues and hoof horn.”
Research conducted in heat-stressed Holstein steers demonstrated that feeding Zinpro® Availa® Zn helped animals maintain dry matter intake during heat stress compared to sulfate mineral sources. Researchers also observed improved gut morphology and stronger epithelial integrity in animals receiving the zinc supplement. These animals also exhibited lower rectal temperatures during heat stress periods, indicating reduced inflammation and improved resilience.1
Ultimately, these findings indicate that with zinc, cows are able to direct more nutrients to productive functions rather than stress responses.
The role of other trace minerals
While zinc is one of the most important trace minerals for dairy cattle faced with heat stress, Dr. Kleinschmit says other proven trace minerals also have roles to play. These include:
- Copper: Functions as an antioxidant and supports immune response
- Manganese: Supports antioxidant systems and glucose metabolism
- Cobalt: Provides for vitamin B12 synthesis in the rumen, which supports energy metabolism
- Selenium: Functions as a key antioxidant, protecting cells from oxidative damage
- Iodine: Supports metabolic regulation and immune function
“All of these different trace minerals are going to make the cow much more resilient to the stresses that occur during the summer months of extreme temperatures,” says Dr. Kleinschmit.
The bottom line
Dr. Kleinschmit recommends a proactive approach to mitigating heat stress, including managing the environment and feeding diets with unrivaled trace minerals to help strengthen gut integrity, support immune defenses and maintain cellular resilience. In most parts of the country, heat stress is unavoidable, but losses to the bottom line don’t have to be.
For more insights on how trace minerals help minimize the impact of heat stress, visit zinpro.com/dairy.
About Zinpro
For more than 55 years, Zinpro has improved the health and wellbeing of both animals and people as a pioneer in the research and development of performance trace minerals and innovative nutritional solutions. As a family-owned, privately held company, our steady growth can be attributed to employing a world-class team of experts, manufacturing quality products and our steadfast commitment to helping our customers advance the health and performance of their animals. With products marketed in more than 70 countries worldwide, Zinpro is the global leader in advancing animal performance through greater nutrition and is dedicated to creating smarter practices for a better, more sustainable world. To learn more visit zinpro.com.
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