The purpose of layer management is to provide a proper condition that can ensure the optimum performance of the birds. Given reasonable conditions, brooding hens are very successful at hatching their chicks, but good hatchability using artificial incubation (both large and small) relies on careful management of temperature, humidity, ventilation, position and egg turning. During incubation, the egg loses water vapour through its shell, the rate of water loss depends on both the shell structure and the humidity of the air surrounding the egg