What is the optimal temperature for poultry?

A successful poultry farmer knows precisely what the situation is in the poultry houses. Do the climate conditions match the needs of the birds? Is the feed intake as it should be? Is growth proceeding as planned? Are the feed costs per egg lower than the income per egg? All of these factors help farmers achieve the best results.

The house climate is one of the key factors that influences the Ideal temperature for poultry. And one of the most important aspects that affects the climate is the temperature. And that is where we can help. Whether it concerns animal welfare, cost savings or technical performance and results, animals enjoy the best conditions when they feel comfortable. In relation to the temperature, this means the farmer must ensure the poultry are in their thermal comfort zone.

Creating the optimal temperature will not only boost the performance of your poultry - an efficient ventilation system also saves costly energy.

What is the comfort zone?

Animals must feel comfortable in the house, which means the temperature must also be correct. Ideally, the temperature is precisely the way the animals like it. In this case the animals are in their thermal comfort zone. If the temperature is too cold, the animals will adapt their behaviour. They will huddle together to take advantage of each other's body heat. Or they will increase their feed intake because more energy is needed to raise their body temperature. This diverts the energy value of the feed to maintenance instead of growth or egg production. In more serious cases, the birds may become ill. And in the worst case scenario, too low temperatures can cause mortality. Extremely high temperatures cause problems for other reasons. The birds will eat less if the temperature is too high. And a lower feed intake leads to less growth. Or lower egg production. Here too, extreme temperatures can cause illness. The birds can suffer from heat stress which in the worst case can be fatal.

It is therefore vital to ensure the correct temperature for reasons of animal health and welfare and to create the perfect climate for good technical results. So it’s simply a matter of using temperature sensors to check if the temperature is correct. Or not? Or is there more to it?

What is the ‘correct’ temperature?

A temperature sensor measures the ambient temperature. The ambient temperature is an important indicator to determine whether the temperature is correct, but it is not the only indicator. We want the birds to experience and feel that the temperature is right for them. This involves measuring other parameters in addition to the ambient temperature. There are two other important factors that determine how an animal feels temperature: (relative) humidity and the cooling effect of wind speed.

Humidity influences how we experience temperature. For example, an ambient temperature of 30 degrees may feel pleasant or oppressive depending on the humidity. So we start by measuring the humidity. We can use this measurement to the calculate the extent of influence the humidity has on the perception of temperature. Depending on how the climate control system is configured in the house, the temperature and humidity can be influenced by controlling the cooling, heating, ventilation and humidification. But regulating the temperature and humidity individually is not enough.

In more advanced systems, the temperature and humidity are not controlled separately. Instead the climate controller determines the temperature setpoint by factoring in the effect of humidity. With high relative humidity, the setpoint in degrees Celsius can be set slightly lower, because the effect of the temperature combined with high humidity means the animals feel that the temperature is higher than the actual temperature expressed in degrees Celsius. And with lower levels of humidity, the climate controller maintains a slightly higher setpoint.

Take a moment to think about this. If the humidity is not taken into account when setting and controlling the temperature, the temperature measured in degrees Celsius may be correct, but the apparent temperature - i.e. how the temperature is perceived - may be incorrect. So the farmer thinks the birds are happy in their comfort zone, but in reality they are too cold or too hot. With a host of potentially negative consequences. Perhaps they are suffering from heat stress. Or are on the point of developing a dangerously low body temperature. Whatever the case, the technical results will suffer. The feed conversion rate may decrease. Or the feed costs per egg may increase. Growth may slow. Egg production might fall.

Fortunately, Fancom can offer the solution. Our climate control systems have a feature for automatic humidity correction. This means the controller automatically adjusts the setpoint in degrees Celsius based on the measured humidity. We call this setting for automatic correction HumiTemp.

What is windchill?

The cooling effect of wind speed is another important factor to consider. In most climate zones, cooling during periods of heat is necessary. You can use misting systems or cooling pads for example. However, in most poultry houses cooling starts by creating a higher wind speed. This is done by activating the tunnel fans at one end of the house so the air is drawn through the building. This creates a similar effect to the one produced when we use a fan to cool down on hot days: this action does not actually reduce the ambient temperature, but we do experience a cooling effect.

Here too, it’s important to think about what this means. The ambient temperature does not fall, but the animals experience the effect of this breeze as cooling. This demonstrates that your temperature sensors do not tell the entire story of how the temperature is perceived. So once again, you risk assuming the birds are in their comfort zone because the readings say so, but at the same time you notice symptoms that indicate it is too cold. Unnecessarily high feed consumption, poor growth or lower egg production, birds huddled together instead of spread out over the house, illness and in the worst case, mortality.

Net effective temperature

And Fancom offers the solution for this problem too in the form of a special setting in its climate controller for poultry. The net effective temperature (NET) is an index that indicates the apparent (felt) temperature based on the measured ambient temperature corrected for the influence of humidity and wind speed. The NET is a more reliable indication of the apparent temperature than only measuring the ambient temperature. And therefore it is an important indicator that shows whether your birds really are in their comfort zone.

Ideal temperature for poultry farm - Lumina 38 screen.jpg

What does this mean in practice?

The attached photo was taken on a broiler farm in Australia, with houses that measure 168 metres long. The large 27.2 degrees indicates the ambient temperature in the house. This figure is based on measurements taken at six different locations in the house. The figure on the lower left shows the birds have been in the house for 41 days. For broilers of this age, 27.2 degrees is too hot.

Next to 27.2 is a second figure: 20.6. That is the temperature corrected for the influence of humidity and the cooling effect of wind speed. For broilers aged 41 days, this temperature is fine.

In addition, the measurements taken at six different locations in the house show that the difference in temperature between the various zones is no more than 1.5 degrees. This means that all the birds in the house are within their thermal comfort zone.

Growth continues

The effect on the technical results is also obvious. This producer also has an weighing system with weighing platforms at two places in the house. The difference between the average weights measured at the front and at the rear of the building is just 50 grams with an average weight of 2.5 kilograms. This is a negligible difference of approx. 2%. This was measured in a situation where all tunnel fans are operating at almost maximum capacity. In other words, a situation with a high wind speed, conditions that usually make maintaining a constant temperature very difficult.

Let’s imagine what could have happened if the producer had only taken the ambient temperature into account. He might be led to believe the broilers were experiencing a temperature of 27.2 degrees: 6 degrees higher than the setpoint temperature. His first thought could be to lower the temperature by 6 degrees. But in that case, he would actually be reducing the apparent temperature experienced by the broilers to 15 degrees, with disastrous consequences.

Is that all there is?

No. Controlling the control is complex. And it consists of more than creating and maintaining the right temperature for the animals. However, using our climate controller with an activated NET setting is a very important step in the right direction. You can rest assured that the birds really are in their thermal comfort zone. Paving the way for a better climate for success. The benefit is that the climate controller takes care of this fully automatically.

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