QUALITY OF LAYING HEN EGGS DURING STORAGE DEPENDING ON EGG WEIGHT AND TYPE OF CAGE SYSTEM (CONVENTIONAL VS. FURNISHED CAGES)

The aim of the study was to demonstrate the relationship of egg weight and egg quality traits with storage time and type of cages in which the laying hens were kept. The material consisted of 960 eggs from same age Hy-Line Brown hens kept in conventional and furnished cages at the same time in one building. The eggs were randomly collected, sorted by weight (S, M, L and XL), and stored under controlled temperature and humidity conditions. All eggs were weighed on days 1 (day of laying) and 28 of the experiment. During the same time they were candled to determine depth of the air cell, and 60 eggs from each subgroup were chosen to evaluate quality traits (egg weight and egg specific gravity), shell characteristics (shell strength, weight, thickness and density), and interior quality of eggs (albumen height and pH, yolk colour, weight and pH). The eggs (especially those from the heavier weight classes, XL and L) from hens reared in furnished cages were characterized by significantly smaller quality changes (egg weight loss, yolk proportion, albumen height, Haugh units) due to storage time in relation to those from hens kept in conventional cages. This fact could point to their better suitability for consumption. In addition to the housing system, changes occurring in eggs during storage should also be considered in terms of their weight class. Economically important egg traits (e. g. egg weight, shell strength) were better in eggs from furnished compared to conventional cages.