Preventing heat stress can have an impact on your operation.

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Cost calculator - Production
Cost Calculator - Production
the system

Summer Production levels can be severely impacted by heat stress.  Many farms plan for and accept summer drops of 10 - 20%.

The calculator is showing a representation of the cost of loss of production on a US farm, milking 100 cows.  These numbers can be changed to reflect information for different areas across North America. In the example shown the US farmer experienced a 10% drop for 4 months, which equalled over $10,000.00 of lost income potential.

Research performed by OMAFRA has proven that drops in production can reach as high as 35% in some Canadian herds.  US research shows similar results.

What do the experts say…

Lactating cows exposed to high temperatures and humidity usually eat less and produce less milk.  Heat stress is one of the major concerns which affect the production potential of dairy cattle almost in every part of the world.  As temperature and humidity rise it can have a negative effect on feed intake lowering dry matter intake. This ultimately leads to a decrease in milk production both in volume and components. Below are some key points on how production can be affected.

  • High yielding cows are more susceptible to heat stress than low yielders.
  • Heat stress can increase body temperature which may affect the fat synthesis in the mammary gland.
  • Reduce the milk production - Internal metabolic heat production during lactation can further reduce the resistance of cattle to high ambient temperature, resulting in altered milk composition and reduction in milk yield.
  • Reduce the milk quality - Affect the various components of milk such as fat (%), solid-non-fat, protein, casein and lactose content.
  • It can increase the somatic cell count indicating the reduction in the quality of milk produced.
  • It can also cause endocrine disbalance such as altering the levels of prolactin, thyroid hormones, glucocorticoid, growth hormone, estrogen, progesterone and oxytocin which ultimately affects milk production.
  • Higher udder temperatures may also cause mastitis in dairy cows.
  • Triggers mammary gland involution accompanied with apoptosis and autophagy decreased amount of mammary epithelial cells can ultimately cause a decline in milk yield.


Heat stress is considered to be adversely impacting both quantities as well as the quality of milk produced. Higher temperatures and humidity have the most impact during the first 60 days of lactation when high producing cows are in negative energy balance and making up for the deficit by using their stored reserves. Higher yielding cows are more affected than lower ones because of the upper critical temperature shifts and becomes lower as feed intake and heat production increase.  Higher producing cows generate more heat pushing her core body temperature up faster and pushing her internal (CBT) temperature higher faster.

The real problem with a heat stress event is that not only are you losing production during the heat period, but you have also lost peak production you will never regain. If a cow is stressed during the climb toward peak production, that stress will prevent the cow from ever reaching its true peak.

If a stressed cow is already at or past peak production, it will drop in production and never return to that level until her next lactation. Once the temperatures start to come down, it actually takes several months for production levels to return.

If we look at the annual average production curve (above in photos), you can see that milk production is finally returning to peak highs as temperatures start to rise again. Add into the equation that these stressed cows are also going through the fall feed change, and you have a recipe for disaster.

The moral of the story: Reduce the cows’ stress load as much as possible. Herds that have heat prevention measures in place often see less of a dip in summertime production and also tend to recover more quickly. CowKühlerZ can offer a solution to heat stress issues that may be causing concerns in your herd.

What can CowKühlerZ do…

CowKühlerZ offers a solution to heat stress that will limit the effects of heat stress on your herd and help you to maintain production levels regards of heat events. Research has proven that evaporative cooling is the most effective method of lowering a cow’s core body temperature. 

The CowKühlerZ system gives you the flexibility to manipulate the environment in your barn to optimize your cow's core body temperature. A high-velocity fan with a very focused airstream is mounted above the stalls or over the bedding pack. A timed, fine mist that acts like "imitation sweat" evaporating off the coat and causing a chilling effect that maintains core body temperature with the optimal range. It’s this mist that provides the “cream on top” to the system's operation.  It is all controlled by an intuitive controller that continuously monitors the conditions in your barn. Offering you peace of mind that your cows are being kept comfortable and cool at all times. Holding Area Systems are comprised of all the same components but offer cooling in the most stressful area of your barn without a worry, adjusting to the conditions seamlessly.

Customer testimonial

Our customers have had some phenomenal results since installing their CowKühlerZ systems. We often hear feedback like, having a system that turns itself on when it’s needed, and turns itself off when it’s not needed is so slick. summer production levels are at an all-time high. This is what one customer had to say...

This past summer (2019) since installing the system in April 2019 we maintained a consistent production level of 9000L every pick up regardless of heat events. In summers prior we would experience drops of 800-900 L per pick up and then we would struggle to and maybe never recover those litres. This year the milk yield stayed consistent; we shipped the same number of litres week after week regardless of heat events. We are very satisfied with that improvement.

The bedding stays dry and the SCC is below 100,000. We are very happy with our SCC. Having water over the beds has not caused the SCC to rise. The droplets are small and they evaporate as they land on the cows in the stall. As long as the stalls aren’t empty for long periods of time the bedding stays dry.

The CowKühlerZ system takes the workload of maintaining comfort in the barn off us. The controller takes all the effort out of it. The variable speed is kicking on before your even thinking about needing the fans. It really cuts on labour needed to manage the barn.

There is definitely increased lying time in the summer, when we come in the barn on a hot summer day the stalls are full, the cows are lying down and chewing their cuds. I notice the cows are chewing their cuds so much more than they ever used to. We know they are happier and healthier since putting in the CowKühlerZ system.

 A farmer near Woodstock ON

In Conclusion 

Preventing the impacts of heat stress can have a major impact on summer production levels. Additional benefits can be found in both reproduction and the health and well being of your herd, please check them out on the website.

Taking a few minutes to calculate heat stress losses and their impact on your dairy’s bottom line can help you strategize for better heat stress prevention, which could mean more milk, improved fertility and healthier cows and calves.

If you would like to run your numbers through the cost calculator please follow the link and fill in the form below and we will send you a PDF version of your calculator.

Cost calculator Link



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