Preparing a home for day-old chicks: Climate and ventilation

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. This means they are especially dependent on us to provide them with a comfortable temperature to grow for the first 2 weeks of life. For a good start, healthy life, and optimal growth not only temperature should be optimal but also the relative humidity and air composition.

Chicks have a narrow comfort zone, where they are not using energy to produce or lose heat to maintain the ideal body temperature of 39 degrees Celsius for the first five days of life. Following the first 5 days, the average body temperature is 41 degrees. 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, litter, and house temperature should be at an optimal condition by the arrival of the chicks (Figure 1). The 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 the litter is placed.

Figure 1: Only an optimal floor and house temperature makes sure that both resting and active chicks are within their comfort zone.

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.

Not only the temperature but also the relative humidity (RH) determines the perceived temperature. When humidity is high, it is 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 until 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. 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 3,000 ppm. However, the level of CO2 in the stable should not rise above 2,800 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 2,800 ppm.

Research shows that high ammonia levels impair the immune system and increases 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.

For optimal performance, it is very important to provide your chicks with a comfortable climate in which temperature, humidity, and air composition are optimally regulated. Though these are the best industry standards, nevertheless, the best method to monitor chick comfort by observing chick behavior and adapting to the climate accordingly.