heating during brooding period

Day-old chicks are poorly equipped to regulate their metabolic processes and body temperature. As a result, young chicks are dependent on the environmental temperature. Providing a comfortable environment during the first weeks of your chicks’ lives is crucial to a successful growing phase. But what is a comfortable environment for your flock?

Research has shown that chicks develop the ability to regulate their body temperature around 12 to 14 days of age. We should provide them with a comfortable temperature to grow. For a good start, a healthy life, and optimal growth it’s not only the temperature that should be optimal. Also, relative humidity and air composition should be regulated. Therefore, especially in wintertime, a proper heating of the houses is a necessity. We will go through the different items in this article.

Chicks have a narrow comfort zone, where they do not use energy to produce or lose heat to maintain an ideal body temperature. Once their body temperature leaves this comfort zone, the chick will have to compensate and use energy to maintain body temperature instead of growth and development.

To support your chicks right from the start, the floor and house temperature should be in optimal condition by the arrival of the chicks (Figure 1). Floor temperature is important as the chicks have large surface contact with the floor. This is why it is preferable for the house to be heated before litter is placed.

When to start heating depends on the vacancy period and stable. Typically, it is recommended to start heating three days prior to delivery. The recommended floor temperature is 28–30°C with an ambient house temperature of 36°C. Keep in mind that temperature sensors are often placed much higher than the height of the chicks, so the house temperature should be reached six hours before arrival.

Table 1: Floor temperature is important to ensure chick health and success.

Not only the temperature but also the relative humidity (RH) determines the perceived temperature. High humidity makes it difficult for a chick to expel excess heat through evaporation. Therefore, it is essential that the temperature-moisture index is in balance. The temperature-moisture index is the sum of temperature (in °C) and relative humidity, as a rule of thumb the temperature moisture index + age of the flock in weeks should not rise above 90, if it does additional ventilation is required.

For example, a house temperature of 28°C with a relative humidity of 60%. Added, these two numbers equal 88, which is below the cautious number of 90. The chicks can successfully thrive in this environment when they are up to two weeks of age. A temperature-moisture index of less than 70 is perceived to be too cold.

The ideal RH for collection is between 60–70%. After the chicks are collected, the house temperature must be adjusted to the relative humidity to create the right conditions. In case the RH is very low (<40%) the RH should be increased before adjusting the house temperature to the RH. If the house temperature is adjusted at a low RH, with the principle of the temperature-moisture index, the perceived temperature will be too high. Also, as with any management principle, do not rely on systems but look at chick behavior and body temperature to check actual climate conditions.

Essential to sustain life, ventilation of your poultry house supplies fresh air. If air is not replaced in an enclosed poultry house, the concentration of carbon dioxide, ammonia and other gases will increase to unacceptable and even mortal levels. Ventilation helps maintain a livable air composition and reduces extremes in temperature and humidity.

According to the European guidelines, the maximum legal concentration of CO2 is set at 3000 ppm. However, the level of CO2 in the stable should not rise above 2800 ppm. If it exceeds this level respiratory and cardiovascular problems will occur, due to the excessive strain on the heart it can also lead to heart failure and ascites. Generally speaking, the lower the CO2 concentration, the better. However, this should not be at the expense of other climate conditions—for example having a cold house at the expense of ventilation—as long as the CO2 is below 2800 ppm.

Research shows that high ammonia levels impair the immune system and increase respiratory disease in birds. Ammonia production can be reduced through the control of relative humidity, which is regulated by ventilation. A relative humidity level of 50–70 percent is recommended to minimize ammonia production and dust.

Finally, fresh air must be introduced uniformly. It should also mix well with the existing house air and should be circulated properly. Mixing the incoming air with the inside air prevents the cooler air from settling and cooling the birds.

Standard heaters are basically gas cannons with fans to distribute hot air through the barn, usually, they are placed under the roof to distribute the hot air and achieve a good blending before the air arrives on bird level. If the heating of the firmly installed heaters is not enough, usually mobile gas heaters are placed in the barn. No matter which type of gas heater is used, there is always combustion involved, and therefore CO2 levels have to be checked regularly, especially, when the heaters run a lot during cold periods.

More recently indirect heating systems became more popular, especially in combination with biogas plants or solar panels. Heating will be achieved indirectly via hot water radiators or floor heating. The advantage of the system is the positive influence on air quality (CO2-levels & humidity) and cost savings, if the energy to heat the water is produced on farm. The disadvantage is the longer heating period, especially, when preparing a house for a new flock, the heating system runs longer to achieve the demanded temperatures.

If brooding is taken place in rings, so called gas brooders are also still common to heat a specific area in the rings for the DOCs. With that system, the house doesn’t have to achieve the full temperature as a whole, as there are comfort areas for the birds.

The major heating systems can also be combined in houses to reach the best result and limit costs. As mentioned before it is an absolute must, to combine the heating system properly with the ventilation and cooling system in your house to achieve adequate climate throughout the cycles as requirements of the birds as well as the external climate change constantly.

In conclusion, maintaining an optimal environment for day-old chicks is crucial for their growth. Key factors include proper temperature, relative humidity, and air composition. Effective heating systems and careful ventilation management are essential to avoid respiratory issues and ensure comfort. Farmers can support healthy chick development by providing a stable environment, leading to successful poultry farming.