A lot to gain with ventilation in the poultry house

The minimum and maximum ventilation requirements for poultry houses are subject to revision, that is the conclusion of Wageningen University in the Netherlands.

Current requirements are close to ideal, but not as close as possible. The University plans to dive further into the finesses of optimal ventilation. The key is not to ventilate according to the amount of kilo’s in the house, but ventilate according to metabolic weight and take the effects of wind chill into the equation.

Research has shown that there is a lot to win with proper ventilation. The metabolic weight of small chicks is about double of the actual weight. When the chicks weigh in at around 1 kilo the metabolic weight is equal to the real weight and above 1 kilo the metabolic weight is a little lower. That means that minimum ventilation at the start of the round should be cranked up, while at the end of the round maximum ventilation can be somewhat reduced.

To make things even more complicated there is the effect of wind chill. According to Wageningen University the ideal temperature of the broiler is the absolute air temperature (as shown on a thermometer) + the relative humidity = 90. Above the value of 115 a broiler has serious heat stress, below 50 cold stress.

In practice that means that at 20 degrees and a humidity of 50 a broiler is cold. The other way around, at an comfortable 20 degrees at a humidity of 90 the bird has serious trouble to loose body heat unless wind speed is added to the equation. An air current of 1 meter per second at 35 degrees and a humidity of 50 can chill up to 10 degrees.