I already went through business with another dom hen that had a good percentage of her eggs hatch starting about day 11 of incubation because of excessive heat. All nesting sites now much more shaded but we have had a good 10 days of >100 F during interval of last clutches being set. When the staggered hatch business occurs, the whole clutch is pulled and placed in incubator. I am just using the hens going broody as a barometer for my measure of quality. Hens that pass will have next years hatching eggs incubatored and brooded artificially.