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Avoid. Heat. Stress.


Hot weather also means a higher risk of heat stress for herds on dairy farms. Due to climate change, heat stress is a growing problem even in moderate climate regions. Heat stress is an enormous burden for the animals, which can have dire consequences for productivity and animal health on your farm. With smaXtec, you can accurately detect heat stress and take immediate action to relieve the cows. The result: a healthier herd with stable milk yield and better fertility, resulting in less work and costs for your farm.


From the USA or Europe to Africa and Asia, weather authorities across the globe are expecting a significant increase in heat waves in the coming years, which may also be longer and hotter than before. While a day is commonly called a heat day when outside temperatures exceed 90°F, the critical upper limit for cattle is already reached at around 78°F, which means that heat stress can quickly develop in dairy cows on hot summer days.


How does heat stress affect milk yield?

Heat can become a real problem for dairy farms, as heat stress causes a drop in milk production in dairy cows, which can directly impact your bottom line. High-yielding cows are more susceptible to heat stress than cows with lower milk production. Studies show that milk yield can decrease by about 16% to 30% in the current lactation and by as much as 11 lb. per day (5 kg per day) on average in the following lactation due to heat stress.


Animal health also suffers, as cows reduce their feed intake in hot weather and often don’t drink enough water, even when there is sufficient supply. Additionally, prolonged heat can lead to increased mastitis, foot problems and ruminal acidosis. In the worst-case scenario, the significant circulatory stress caused by the heat can lead to the death of the animal.


How does heat stress affect fertility?

In extreme heat, cows show less obvious and shorter signs of estrus, which in some cases may be absent altogether, making it more difficult to detect estrus. Heat can also cause calving problems, making it harder to manage herd fertility efficiently.


During the important transit phase, cows should receive special attention during heat stress, as symptoms such as decreased feed intake and the resulting energy deficit during the period near parturition can have a particularly negative impact on cow health.


With smaXtec health monitoring, you can detect both calving and typical subsequent diseases such as milk fever, displaced abomasum or retained placenta at an early stage, thus ensuring a good start to lactation.


Detect heat stress earliest possible – with smaXtec.

All measurement data of the smaXtec Bolus are of great importance for the early detection of heat stress. Heat stress symptoms are recorded by the smaXtec Bolus individually for each animal and with the highest precision (±0.018°F relative measurement accuracy):

· Increased temperature

· Decreased rumination

· Reduced activity

· Insufficient water intake


smaXtec calculates the group temperature based on individual temperature notifications to also detect changes at the group level and automatically notifies you of heat stress.


The group metric temperature is available in the smaXtec App as well as in the smaXtec Messenger and makes it even easier for you to detect slight changes in temperature as the curve diagram is shown in a narrower temperature scale (96-111°F) and without drinking cycles.


The smaXtec Climate Sensor measures outdoor temperature and humidity and, based on this, automatically calculates the THI (Temperature Humidity Index), which maps the probability of heat stress. If the THI is elevated, you are notified and can take immediate action to improve the climate inside the barn.



Heat stress can be measured using the temperature humidity index (THI). The THI is calculated with a formula that is composed of air temperature and relative humidity:

THI = (absolute temperature °C) + (0.36 * temperature of dew point °C) + 41.2

· THI ≥ 72: mild heat stress

· THI ≥ 78: moderate heat stress

· THI ≥ 82: severe heat stress


Avoid consequences of heat stress

In addition to the immediate consequences of heat stress such as reduced milk yield, reduced estrus and poorer health as a result of overheating, there may also be secondary diseases such as ketosis, rumen acidosis, mastitis or hoof problems after the disease has been overcome. With smaXtec, farmers can take timely action against these consecutive symptoms and avoid negative consequences for herd health and farm success.


Contact smaXtec and implement the most comprehensive system for monitoring health and reproduction in dairy cows on your farm and start improving your key success indicators today.



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