Storage of hatching eggs: The interaction between parental age and early embryonic development

Abstract
Embryos in eggs laid by older birds were developmentally more advanced, both at oviposition and after 24-42 h incubation, than those in eggs from younger birds. Storage of eggs caused shrinkage of the blastoderm. The amount of shrinkage decreased with parental age. The developmental age of embryos after 42 h incubation increased with parental age but was reduced by storage, with embryos in eggs from middle-aged birds (35-40 wk of age) being least retarded. The rate of development in fresh eggs increased with parental age. Storage reduced the rate of development equally at all flock ages. The number of malformed embryos increased with storage time. After 14 day storage there were fewer abnormalities in eggs from birds between 31-49 wk of age than in younger or older birds.