Effect of pre-incubation storage of 9 days on incubations traits viz; incidence of dried-off eggs, fertility, hatchability and embryonic mortality was studied in 6 divergent lines of Japanese quails. The incidence of dried-off eggs was significantly higher in body weight selected lines as compared to plumage and egg-colour variant lines. Fertility and hatchability (egg-set basis) of improved lines was significantly lower than the unimproved lines but the hatchability on the basis of fertile-eggs was similar for the lines belonging to two genetic groups. Early embryonic mortality was higher in the improved lines as compared to the unimproved lines. The incidences of dried-off eggs, fertility, hatchability and embryonic mortality were significantly influenced by storage length. The decline in hatchability with prolonged storage resulted from increased early (0–11 d) and late (12–18 d excluding pipping) mortality. The linear regression of fertility, hatchability and embryonic mortality on storage length accounted for 45 to 85% of the variation in these traits. The quadratic terms of regression were significant for fertility and hatchability of eggs-set basis. The curvilinearity resulted from a steep decline in hatchability beyond 6 days of storage. The rate of decline in fertility, hatchability and embryonic mortality was comparatively higher in the improved strains as compared to unimproved lines.
Storage length, hatchability, fertility, embryonic mortality, divergent lines, Japanese quails
