Hatchery personnel must not conduct any procedure that interferes with the egg's natural defense. Producers must make every effort to collect and store eggs so that natural protections are not compromised. Keeping egg shell surfaces dry is very important to prevent excessive microbial contamination and shell penetration. Without benefit of aqueous water the potentially dangerous microorganisms have little opportunity to invade the egg shell and infect the embryo. Sweating of eggs as they are moved from warm to cool environments must be prevented if sanitation programs are to be successful.
Embryos have the same requirements prior to pipping that the chicks have following hatching.
They have the need for heat, moisture, and a high-quality source of air. They can be severely affected by harmful fumes originating from many chemicals often found in or near the hatchery. Although hatchability may not be affected, the quality of the chicks can be reduced. Whenever unusual odors are detected in the hatchery to come from detrimental chemicals, the product must be removed. This applies to all chemicals within the hatchery, including disinfectants.