In this study, hatchability characteristics and some internal egg quality characteristics of 0, 2, 3, 4, 6 and 8 d stored Fayoumi eggs were examined. It was determined that the effect of storage time on hatchability, hatchability of fertile eggs, embryonic mortality, hatchling weight, albumen weight, yolk weight, albumen index, yolk index and Haugh unit was significant (P<0.05). There was no positive or negative effect of storage time on the fertility rates, but there was a negative effect of storage time on egg weight, hatchability, embryonic development and hatchling weight on d 4 (P<0.05). It was determined that prolonged storage time caused a decrease in the albumen weight, yolk weight, albumen index, yolk index and Haugh unit value of Fayoumi eggs. Fayoumi eggs should not be stored more than 3 d.

Aim: An experiment was conducted to determine the effect of egg weight on hatchability, embryonic deaths and hatchling weight of three rural breeds (Fayoumi, Desi and crossbred (Rhode Island Red X Fayoumi) chickens. Materials and Methods: Three different egg weight groups classified into small: (<41g), medium (41-45g) and large (> 45g) were used in the experiment. A complete randomized design was used for the experiment. Simultaneously quadratic type equation was used to determine the egg weight for optimum hatchability and hatchling weight. Results: Percentage hatchability of medium-sized eggs was higher (P < 0.05) than those in large sized eggs. Similarly, large–sized eggs had higher (P < 0.05) percentage hatchability than small sized eggs in all breeds. Hatchability percentage changed by ratio 0.4077 with one unit change in mean egg weight of Fayoumi. The hatchability changed by ratio 0.5488 with one unit change in egg weight of Desi. The hatchability changed by ratio 0.3767 with one unit change in egg weight of crossbred chickens. Mean hatchling weight in Fayoumi eggs changed by ratio of 0.6760; Desi eggs by ratio of 0.5955 and crossbred chicken eggs by ratio of 1.3613 with one unit change in mean egg weight. The overall mean hatchling weight as percentage of mean egg weight in case of Fayoumi was 67.10, in Desi 62.42 and 68.36 in case of cross birds. There was no evidence that hatchabilitypercentage increased with increase in egg weight in all the three strains of birds. Small-sized eggs had higher (P<0.05) embryonic deaths than those of medium and large-sized eggs in three breeds. Hatchling weight from large eggs were (P < 0.05) higher than those of small eggs in three breeds. Mean hatchling weight of Fayoumi changed by ratio 0.676 with one unit change in mean egg weight. In case of Desi chickens, mean hatchling weight changed by ratio 0.5955 with one unit change in egg weight. In case of crossbred chicken, mean hatchling weight changed by ratio 1.3613 with one unit change in egg. Conclusion: This study revealed that medium sized eggs were more appropriate for better hatchability percentage and lower embryonic deaths in three rural breeds. However, large sized eggs were suitable for better hatchling weigh