As a hen ages, the size of her egg increases, and
the thickness of the shell decreases. The pore
length is determined by shell thickness; thus,
thinner shells are more prone to bacterial
contamination caused by increased penetration
ofbacteria from the surface of the egg [3, 6].
The aim of this the work was evaluated effect of
disinfection of Oravka hatching eggs by formalin
gas and ozone on fertility, hatchability,
spontaneity of chickens hatching and embryonal
mortality during incubation.