Physiology Department, Faculty of Veterinary Medicine, Cairo University



In the poultry industry, fertility of broiler breeders is of major concern to ensure maximum economic returns from numbers of chicks produced per hen housed. Over the past decade significant progress has been made in under- standing the physiological mechanisms that lead to successful fertilization in poultry and the control of sperm selection and storage in hen's oviduct and its effect on subsequent fertilization.

Also significant progress has been made in clarifying the factors which influence the efficiency of sperm storage and subsequent fertility, including the timing of insemination, the duration of egg production and the age of the hens.

In conclusion individual males or females are " fertile " when they are "capable of breeding" and the result of their breeding is the "fertile" egg which is capable of "hatching". A fertile egg will be one that has been fertilised and has a formed embryo at oviposition. "Fertility" will refer to the fertile status of groups of eggs laid over a period of time by single hens, by small groups of hens, or by commercial flocks, it is usually expressed as percentage of the total eggs laid.