Summer is just around the corner and with it, heat stress. Did you know that according to the Foundation for Food and Agriculture Research in 2019, heat stress costs the US dairy industry approximately $1.5 billion…per year? Higher temperatures can affect your herd, and in turn, can hurt performance, production, and profit.

With afternoon humidity of 60-70%, cows will start to see mild effects of heat stress at temperatures of 75-77° Fahrenheit – that’s a temperature humidity index (THI) of 74. Mild heat stress occurs at a THI of 68, moderate at THI of 72, severe at THI of 80, and a THI of 90 is a dangerous level. Thankfully, there are several steps you can take to combat the hot summer months. Alleviating heat stress is critical, and now is the time to prepare.

Here are five cool tips to reduce heat stress in your dairy herd.

What is the main nutrient used to make milk? Water! And cows need lots of it when temperatures rise. On average, a cow can consume 30 gallons of water on a normal day. When you factor in high humidity, that number can double. Make sure to increase water availability for your herd. Cows will not be as willing to walk longer distances in warmer weather. They must have constant access to cool, clean water in a location that is shaded or close to shade. A good rule of thumb is that cattle will need three-to-four inches of linear water space per head during the summer. Keep in mind, water should be positioned away from the milking parlor and available near the lounging area. By keeping water troughs cool and clean, your cows will have a better chance of beating the heat.

Providing proper shade can decrease a cow’s body temperature. Natural shade, such as trees, is excellent. However, cows will often gather around treed areas, and this congregation could cause mud holes. Over the years trees will die. If trees aren’t available, constructing a portable shade cloth or some sort of lightweight roofing material, will work as an alternative. Another good idea is to provide shade over the feeding area, as this will lead to increased feed intake.

It is quite common for feed intake to decrease during hotter months. When cows eat less this can lead to decreased milk production. To keep their appetites up, make sure they have constant access to fresh feed. Feeding more frequently during cooler parts of the day keeps feed fresh, flavorful, and can increase intake. A tasty tip is to incorporate a covered feed structure that offers shade for cows, so they are more comfortable while eating. Food for thought!

Cows have very little ability to sweat and cool themselves. Allowing access to misters, sprinklers, and fans can help. Look to see where the cows are congregating – this would be a great spot to install misters and sprinklers. To avoid water saturating the udder, don’t leave misters or sprinklers on for too long. Place your sprinklers on a timer to help avoid issues. Always remember to make sure misters are clean, and continuously provide proper airflow with fans. Air flow and constant water are critical to help your cows stay cool.

Higher temperatures can negatively affect milk production and milk fat yield, due in large part to heat stress-induced pH decrease in the rumen and leaky gut. Although it is vital to provide proper heat abatement strategies like we’ve listed, there are also feeding strategies that may assist in reducing lost performance. By providing a suitable additive, such as NutriTek^® by Diamond V^®, you could help promote gut health, immune strength, and overall wellness. Incorporating this feed 30 days before heat stress begins is imperative. This allows for the time needed to optimize the cow’s rumen. Healthy cows perform better, and a healthy gut can help cows cope with the heat. Ultimately, this can result in greater profitability on the farm.

A comfortable cow is important throughout the year but is a bigger challenge in the summer months. By providing proper shade, water, misters, air flow, and feed, you can help your herd stay healthy, happy, and productive. We hope you enjoyed these five cool tips.