Draughts are an enemy of cows. Calves in particular are extremely sensitive to them. Draughts weaken the immune system and increase morbidity of cows. Respiratory diseases are a frequent consequence.  
The following article deals with draughts and their consequences, such as respiratory diseases. We tell you more about how smaXtec helps you to detect respiratory diseases early and thus shorten the treatment period. Some useful tips on how draughts can be avoided are also listed below.
DRAUGHTS AND THEIR CONSEQUENCES
In general, the term draught is understood as incoming air that is clearly cooler than the air in the barn. 
It cannot be clearly defined which wind speed is necessary to reduce performance and impair health in cows. An approximate guideline for the air movement in cold weather is up to 2m/s and in warmer seasons up to 4 m/s. Problems become apparent when animals lay down or stay close to other animals due to a lack of protection options. 
The circulation of the mucous membranes is particularly affected by draught. This may lead to more infections. The greater the temperature difference, the more damaging the influence of a draught on the health of the animals. For this reason, problems often arise, especially in periods of cold, wet weather. Furthermore, high wind speeds occurring during this time are a big problem. A common consequence of poor air quality and draughts are respiratory diseases. Stagnant air or draughts considerably increase the likelihood of pneumonia.
Calves are particularly sensitive to this because they cool down quickly and the microclimate, meaning the temperature immediately above the skin surface under the coat, is destroyed. The immune function of the young animals is weakened by the reduced blood flow. 
RESPIRATORY DISEASES IN CALVES AND COWS
Respiratory diseases can be caused by poor air quality and draughts. But the animals do not only suffer in autumn and winter. Even in summer, on particularly hot days, they can become seriously ill. Calves for example sweat and draughts created by the air movement for cooling increases the risk of respiratory diseases. 
Respiratory diseases have a major impact on the economic success of calf rearing and on the performance of adult animals. Long-term consequences in females include a higher first calving age, higher herd turnover rates and a lower milk yield.  It is even more dramatic in male calves. Once they become ill, consequential damage is inevitable. Their growth is insufficient.  In addition, high treatment costs, decreased weight gain and death as a result of treatment can also be seen as negative results.
Consideration must also be given to the economic impact of respiratory diseases. These types of diseases are among the most complex and most costliest in bovine medicine. Significant financial losses are often the result of increased occurrence of respiratory diseases. The losses are caused by
- the losses of calves,
- the reduced daily weight gain in sick animals,
- poor development of chronically ill calves,
- costs for treatment by veterinarians and for medication
- and the increased time required to care for sick calves
A calculation of the monetary loss is as follows: with a morbidity rate of 30 % and a loss rate of 5 %, there are losses of € 50 per stalled calf. 
But it is not only the short-term losses mentioned above that are associated with respiratory diseases – long-term consequences must also be expected. It must be remembered that only a healthy calf can grow into a high-performance dairy cow. The influence of respiratory diseases and the resulting (possibly long-lasting) breathing difficulties on the later performance of the animals is often underestimated. 
SMAXTEC SUPPORTS YOU IN THE EARLY DETECTION OF RESPIRATORY DISEASES
With the smaXtec bolus, typical symptoms of respiratory diseases can be detected early on. By continuously measuring inner body temperature, even the smallest deviations from the animal’s normal temperature can be detected at an early stage.
Furthermore, sick animals are usually less mobile and show reduced activity. This is also detected by the smaXtec Bolus. The success of the treatment depends largely on the stage of the disease. Early treatment of pneumonia is therefore essential for full recovery.
MEASURES AGAINST DRAUGHTS
The optimum temperature for calves is between + 4 ° and + 20 °Celsius. Dairy cows are most efficient at temperatures ranging from – 15 ° to + 20 °Celsius. <sup<< sup=””>In addition to the right temperature, humidity also plays an important role. Low humidity (35 % – 50 % at < 15 ° C) provides optimal air quality for calves as it reduces germ levels. In adult cattle, on the other hand, the optimal relative humidity is between 35 % and 70 %. 
With the help of the smaXtec Climate Sensor, the decisive parameters are collected, measured and presented in a user-friendly way. In addition to the temperature and humidity, the so-called THI (temperature-humidity index) value is also calculated. This value provides information about heat stress in hot summer months.
There are several ways to fight draughts in the barn. Especially for calves, it is important that they are provided with well-protected shelter. However, making a barn draught-free does not mean sealing it off. It is important to allow air exchange. Even in winter, air exchange should take place four times an hour in order to ensure good air quality and humidity. If fans, light ridges or curtains are missing in the barn, then draft-free sides should be opened. There are also other ways to ensure sufficient air circulation. For example, three sides of the barn can be closed with only one remaining fully open. This may mean it gets pretty cold in the barn but there are no draughts. Other simple tools such as windbreak fences or straw bales can be used to protect animals. Fans are becoming increasingly popular because they do not extract used air from the barn but press fresh air through hole channels into the barn.  In combination with the smaXtec Climate Sensor, fans can be used efficiently and economically, which means they only have to be used if, for example, humidity is too high or there is a risk of heat stress.
As already mentioned above, it is the least harmful for cows if they experience a draught in the feeding area. This is why doors/openings to the feeding table can be left open to guarantee air exchange. Not recommended are draught holes directly above the lying area of the cows, as the cold air falls directly on the cattle and these usually have no way of avoiding the draught. 
Whichever measures are taken, the most important thing is that incoming cold air is slowed down and warmed up before cows come into contact with it.2