Techniques for Identifying Fertile Hens’ Eggs

KOSIN (1944) has described techniques for determining the fertility of unincubated hens’ eggs by examination either (a) with the naked eye, or (b) microscopically, after fixation and staining with alum cochineal. If these techniques are sufficiently accurate, they should be of great value to people working in the field of avian reproduction, provided that chicks are not desired from the eggs under test. With these methods it is not necessary to operate incubators, and, perhaps more important, the fertility of a group of eggs can be determined on the day they are laid, which results in a considerable saving of time. In studies of fertility undertaken at Cornell University, the saving in time and in eggs was thought to be sufficient to warrant further investigation of the utility of these techniques. The accuracy of the macroscopic technique has been investigated by Kosin (1945a). When 182 eggs that had been judged . . .