EN
The objective of the present study was to evaluate embryonic development and hatchability of turkey eggs differing in shell structure characteristics. The experiment was conducted between 4 and 17 weeks of the laying season, on three groups of hatching eggs of heavy-type broad-breasted white turkeys, i.e. eggs with good quality shells, rough-shelled eggs and eggs without shell surface pigmentation. Twenty-five embryos of each group of hatching eggs were analyzed in the 64th hour of incubation. Six incubation series were carried out, each time using 126 eggs of each group (a total of 2 268 eggs), and hatchability traits were determined. Eggs in particular experimental groups did not differ with respect to the size of the germinal disk, the length of the longitudinal axis and the diameter of the tail region of embryos. The widest diameter of the head region of embryos was recorded in rough-shelled eggs (p < 0.05). There were no significant differences between the groups with regard to the average number of somites and brain vesicles in embryos, however it was the highest in eggs with normal quality shells. The hematopoietic system of embryos was more developed in eggs with rough shells and eggs without shell pigmentation. Fertilization rates, embryo viability to 26 days of incubation and hatchability were higher (p < 0.05 and 0.01) in eggs with shells of good quality and in rough-shelled eggs compared to eggs without shell surface pigmentation. Hatchability was found to be very low in the group of eggs without shell pigmentation, reaching only 72.93%. The results of the study indicate that in the 64th hour of incubation the embryos in all groups of eggs were at a similar stage of development, except for the fact that the head regions of embryos in rough-shelled eggs were wider in diameter. It may be concluded that eggs with rough shells and eggs without shell pigmentation are characterized by lower hatchability than eggs with good quality shells.