Four replications of 150 fresh eggs and 4 replications of 150 eggs stored for 7 d under practical conditions (70% RH and room temperature of 15°C) were incubated at a commercial hatchery company [23]. Eggs were collected from broiler breeders aged 45 wk. All the 8 replications corresponding to 8 trays were set at random at the same side of a trolley. The eggs were set in a commercial incubator [24] for incubation. The multistage incubation system was used