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Abstract
The present study was carried out to evaluate whether heating hatching eggs before or during long storage periods, would improve the hatchability traits and productive performance of progeny. A total number of 2700 hatching eggs were collected from broiler breeders (arbor acres) grandparents D line flock at 29 weeks old. Eggs were transported to the hatchery in three groups (900 eggs each) according to the storage periods for 7, 14 or 21 d. All collected eggs were stored in a special egg holding room at 17{u00BA}C and 75 % RH. All eggs in each group were weighed and numbered individually and subdivided into three subgroups according to pre incubation heating treatment as follows: No heating (control), heating eggs 2 hrs., each 3 d during storage (HDS) and 6 hrs., before the storage period. The heating treatment was at temperature of 37.5{u00BA}C and 55 % RH. All chicks were housed in an open system house in separate floor pens. Chicks were maintained under similar environment and management conditions such as temperature, scheme ventilation system, lighting schedule and feeding program stated by the Cairo poultry company (CPC), guideline. The results show that longer storage period without heating had negative effects on egg weight, egg shell thickness, yolk height, yolk index, albumen weight and albumen height. Also, the apparent fertility, hatchability of fertile eggs and hatchability of total eggs were significantly lowered in eggs stored for longer period. Moreover, higher percentage of early, late and total embryonic mortality; piped life and culled hatch chicks were associated with longer egg storage period without heating