Changes in egg structures during incubation and their relationship with hatchability and gosling quality in White...

The study aimed to analyze egg value, hatchability performance, gosling quality, and changes in extraembryonic structures, and nutrient utilization by embryos during incubation of eggs from White Kołuda® geese (WKG) and Biłgorajska geese (BG). The 620 hatching eggs were used, divided into two groups according to breed. In fresh eggs morphometric traits, eggshell and vitelline membrane strength, yolk color, pH, viscosity, and lysozyme activity were assessed. Incubation was carried out for 30 days. Egg weight loss, fertility, embryo mortality, and hatchability were monitored. During incubation (days 7, 14, and 21), changes in pH, viscosity, lysozyme activity, eggshell thickness, mineral composition, and content of mineral, vitamins, and the fatty acid profile in yolk and yolk sac were analyzed. Gosling quality was evaluated according to the Tona score. WKG eggs were characterized by higher weight and surface area, and higher fertility and hatchability compared with BG eggs. BG goslings received higher scores for quality despite lower hatchability performance. BG eggs had a stronger eggshell and higher yolk pigmentation. In both groups, changes in the pH of extraembryonic structures, a decrease in eggshell thickness, and intensive calcium utilization in the final stage of incubation were observed, with modifications of the fatty acid profile and a decline in vitamins A and E as embryonic development progressed. Lysozyme activity and the viscosity of albumen and amniotic fluid changed dynamically during incubation; however, WKG eggs showed higher lysozyme activity at critical stage (day 7) of embryonic development. Goose origin differentiates the quality of hatching eggs, the course of incubation, nutrient utilization, and hatchability performance, which is of practical relevance for breeding and the conservation of goose genetic resources.