Rearing Stage

Two sub-systems come into play during the rearing stage. One, of course, is the heating system, while the other is the minimum ventilation system.
The poultry house is heated using regional space heaters suspended inside the house along its longitudinal wall or, when the house has a closed wall, installed outside the wall. The house warms to the desired temperature in the poultry living area, but hot air naturally tends to rise and concentrate around the top ridge. Right from the first days of rearing, it becomes necessary to exchange the air, i.e., establish what is known as "minimum ventilation." To this end, a number of medium-size fans are installed in the house wall along with motorized vents. This system is operated through the control system using cyclical start-stop activation, so that as the broilers grow the activation periods become longer and the breaks shorter.
The vent system is designed to allow fresh air to enter the poultry house ceiling area at the desired speed. The fresh air then mixes with the hot air that has concentrated at the top of the house, and only then begins to descend to the birds' living area. Air is vented through a number of fans installed in the wall of the house.
If the minimum ventilation fans are working continuously but additional ventilation is still needed, this may be an indication that this stage has been exhausted and the next growing stage has been reached.