Time of oviposition of shell-less eggs.

Abstract Shell-less or soft-shelled eggs, which are covered with little or no shell substance, are quite frequently produced by domestic fowls (Hewitt, 1939). Jaap and Muir (1968) reported that 82 to 90 percent of broiler-type pullets, depending on the strain, laid some defective eggs. Their results also showed that 3.7 to 7.0 percent of the total yolks were laid as either soft shelled or shell-less eggs. Hewitt (1939) suggested that the cause of shell-less eggs is either a failure of the glands in the shell-secreting portion of the oviduct, or violent peristalsis which hastens the egg through this region before a shell can be formed. Other causes suggested include the possibility of the bird being disturbed or some irritation in the oviduct (Romanoff and Romanoff, 1949). Results of Buckner et al. (1922) showed that calcium starvation is not necessarily a causative factor in the production of shell-less eggs, as was once…