Egg storage conditions and manipulations during storage: effect on egg quality traits, embryonic development, hatchability and chick quality of broiler hatching eggs

Abstract

SUMMARY The egg storage conditions including the duration, temperature and egg turning and positioning and manipulations, especially prewarming and preincubation during egg storage, are consistently important components for poultry breeders and hatcheries. This review paper provides a comprehensive analysis of the effects of egg storage conditions and manipulations during egg storage on egg quality characteristics and embryonic development and subsequent effect on hatchability and chick quality. The egg storage duration and temperature have been deeply studied compared with the egg turning and positioning and manipulations during storage. Storing hatching eggs above 21°C for > 7 d increases embryonic mortality and reduces hatchability. Concurrent with insufficient turning or cessation of turning and longer storage durations, these lead to increased embryonic mortality, reduced hatchability and compromised chick quality. Furthermore, it was identified that the potential mechanisms underlying the observed effects of egg storage conditions include variations in yolk and albumen characteristics, gas exchange and blastoderm development, which should equally remain in optimal ranges during storage. Meanwhile, during egg storage period, manipulations comprising prewarming and preincubation are recommended due to their role in increasing embryonic development, hatchability and chick quality. Generally, the effects of the storage conditions are highly associated with the breeder age and timing in case of manipulations during storage. Furthermore, it is essential that studies fully explore the genetic variability and the changes in integrity of external egg characteristics, such as changes in eggshell thickness and conductivity in relation to storage conditions, and their impacts on embryonic development, hatchability and chick quality. Conclusively, understanding the effects of egg storage conditions can help poultry producers implement appropriate strategies to improve overall production efficiency and profitability.