Management procedures

In the field, I observe different management procedures to shorten the hatch window, most of which are used to compensate for poor incubator design. But is a shorter hatch window desirable and can your incubator have any influence? The following procedures are used in practice:   

Transfer patterns are used to move embryos from specific locations (cold areas) in the setter to specific location (hot areas) in the hatcher. This may shorten the hatch window but negatively affect chick quality due to non-uniform embryo temperatures.

Changing the air temperature or carbon dioxide levels of the hatcher when the first signs of hatching chicks are detected is another approach. Both methods should "stimulate" the chicks to hatch. What actually happens is an increase in embryo temperature. A higher carbon dioxide content causes decreased ventilation, which increases the embryo temperature in an air-cooled machine. An increase in embryo temperature negatively affects chick quality. 

A third common procedure to shorten the hatch window is often called “dancing with the trolleys”. This involves moving the trolley inside the incubator between relatively hot and cold spots to equalise the hatch time. This may shorten the hatch window, but can also negatively affect chick quality as it causes uneven embryo temperatures.  

I understand that most managers have to use these procedures to repair the hatch window. However, for optimum chick quality, hatchability and a natural hatch window in any group of eggs, it is very important to ensure and prepare a uniform start-up and uniform incubation conditions through Laminar Airflow. If the embryo temperature is uniform throughout incubation, chicks will develop properly, hatch in HatchCare with maximum hatchability and field performance.