Journal of applied poultry research vol:10 issue:3 pages:221-227
The age of broiler breeders is an important parameter to be taken into account by the hatchery manager. Eggs produced by young or old breeders do not hatch as well as the eggs from the breeders of 40 to 42 wks of age. Field reports indicate that there are quadratic relationships between age of breeders and absolute egg weight loss during incubation, age of breeders and hatchability, and age of breeders and embryonic mortality. There is a trend of optimum relative egg weight loss on Day 18 of incubation for the highest hatchability. These results indicate that the eggs that incubate best are produced by the hens of 40 to 42 wk of age. It is suggested that the egg characteristics and the age of breeders have to be taken into account during incubation in order to design optimal incubation conditions and to improve hatchability. However, because the relative egg weight loss is not linked to the age of breeders, regulation of relative humidity during incubation to achieve optimum weight loss may take into account only the eggs characteristics.