heat stress – 10 Tips & tricks
Next week, temperatures are expected to rise again—reaching up to 30 degrees Celsius. With such high temperatures, heat stress in calves becomes a real threat. Especially your youngest animals struggle to regulate their body temperature during this warm period, which poses a significant risk. How can you prepare?
In the first month of life, the ideal environmental temperature for a newborn calf is around 15 degrees Celsius. You can imagine that in tropical temperatures—especially combined with high humidity—a calf experiences stress. In hot weather, a calf’s skin temperature can rise above 40 degrees. As a result, the animal starts to sweat and pant, loses its appetite, and has an increased need for fluids.
The danger is lurking. To cool down, the calf actually needs energy from its feed. Reduced feed intake slows down growth in the early stages, which ultimately leads to lower milk production—not only in the first but also in subsequent lactations. So what can you do? Recognize the signs of heat stress and intervene where possible. Below, you’ll find our tips to help limit heat stress.
what are the symptoms of heat stress?
With mild to moderate stress, calves will visit the water trough more frequently to maintain their fluid balance. As the stress increases, the animals become more lethargic and are less likely to go to the drinking source. Their appetite also decreases, which is noticeable through reduced feed intake. Do you notice physical signs such as panting or labored breathing? Then it’s time to take action. Heat stress has clearly set in.
Tip 1 – Reposition your housing system to the shade
A simple yet effective measure is to move the calf hutch or calf pen to a cooler location. Ideally, choose a spot with natural shade or create additional shade using a cloth or tarp. Pay particular attention to sunlight in the afternoon hours, when the heat is most intense. Make sure your calves can lie down in the shade during that time.
Tip 2 – cool the roof of the calf hutch
Spraying water on the roof can lower the temperature inside the pen by several degrees. This can easily be done with a garden sprinkler. Additionally, when purchasing a calf hutch, it’s wise to pay attention to good insulation. At Topcalf, you’ll find calf hutches and barns with insulated roofs, which can make a difference of up to ten degrees on hot summer days.
Tip 3 – position your calf hutches not too close to each other
Move your calf hutches or calf pens further apart to optimize air circulation. We recommend placing your calf housing at least two to three meters apart. This allows air to flow more freely between the units. Do you use calf hutches? Then you can slightly raise the back of the hutch to allow fresh air to flow in more easily.
Tip 4 – ensure a good air flow
Fresh air is especially important for calves during hot days. A constant airflow of approximately 2.5 m/s helps reduce heat stress. However, this should be adjusted according to the ambient temperature to avoid creating drafts.
At Topcalf, we choose to install air vents in the rear wall of the calf hutches and barns. This allows you to easily control the additional air intake yourself. Calf pens with extra ventilation openings at the back heat up to twice as little as closed pens.
An alternative for existing calf barns is using a fan or tube ventilation system. Tube ventilation is installed along the ridge of the barn. Thanks to slight positive pressure, fresh air is gradually and precisely distributed throughout the barn via the small openings in the tube.
Tip 5 – control regularly
Under the motto: prevention is better than cure. Keep an eye on the temperature and humidity levels in your calf barn. This allows you to take timely action. Weak animals, such as those already suffering from diarrhea, are even more vulnerable to dehydration. So make sure to give them the extra attention they need. The table shows under which conditions your calves are likely to experience heat stress.
Bron: https://www.dekalverhouder.nl/nieuws/Hittestress-ligt-al-op-de-loer#1
Tip 6 – create access to fresh and cold water
One thing you must not forget is the drinking water supply. Calves must have good access to sufficient, fresh drinking water. During warm periods, clean the water troughs an extra time to ensure water quality.
Tip 7 –move your calves during cooler moments
Moving calves is also a moment of stress for them. Do this during the coolest part of the day—early in the morning or later in the evening. Not only is this a more comfortable working temperature for you as a farmer, but it also reduces stress stimuli for the calf.
Tip 8 – postpone medical procedures for calves
Medical procedures such as dehorning or vaccinations cause stress for the calf. It is advisable to postpone these to a cooler moment—preferably early in the morning or on a cooler day. This helps prevent additional strain on the calf during periods of heat stress.
Tip 9 – reduce the number of flies
Avoiding flies doesn’t have a direct impact on the calf’s perceived temperature. However, during warm periods, it is important to address all potential stress factors. Flies dislike air movement, so ensure proper ventilation. Additionally, heat and moisture create ideal conditions for flies to lay eggs. Regularly clean out your calf pens and consider using a fly control product.
The common thread in combating heat stress lies in a well-managed barn climate, proper nutrition, and the right work protocols. Curious to know what Topcalf’s calf housing solutions can offer you? Get in touch with one of our specialists.
Tip 10 –Keep your calves in smallers groups
Calves have a strong preference for spending most of their time together, regardless of the hutch’s ventilation. This was concluded by researchers at the University of Wisconsin in Madison. What stood out was that calves younger than four weeks consistently chose social contact over a better-ventilated hutch. Calves aged six to nine weeks were more likely to choose the cooler option—a calf hutch with a ventilation flap (Reuscher et al., 2024).
The central thread in fighting heat stress is by providing proper and fresh food, as well as a high quality calf hutch. By realizing a good climate your calf will not experience the heat stress and can continue to grow. Are you curious how we fight heat stress? Feel free to reach out to one of our colleagues.