In this study, hatchability is based on total eggs set;
thus, discrimination between losses due to infertility or embryonic mortality could not be made. From the management
point of view, specific knowledge of the cause
of low hatchability is essential, because good management
of the cocks and hens at the breeder farm could
improve poor fertility, whereas a high level of embryonic
mortality may be the result of poor management of
hatching eggs at the farm and at the hatchery.