Changes in the quality of eggs during storage depending on the housing system and the age of hens

The objective of the study was to evaluate changes during storage time (0, 7, 14, and 21 D) in the weight, albumen quality and its functional properties, and protein content of eggs from enriched cage and free range at 26 and 51 wk of age. Egg weight was affected by a significant interaction between the housing system and the age of hens. Regarding individual factors, heavier eggs (P < 0.001) were obtained with the enriched cage (61.7 g) environment than with free range (59.6 g) environment at 51 wk (P < 0.001) (63.3 g vs. 58.0 g), and freshly laid eggs were heavier compared to eggs stored for 14 and 21 D (P < 0.001). The significant interaction of evaluated factors affecting egg weight loss included the Haugh unit score and pH. Albumen dry matter content was significantly higher in free-range eggs (14.70% vs. 14.0%), in eggs from younger hens (15.0% vs. 13.7%) and in eggs that were stored 21 D. Free-range eggs contained more lysozyme (P < 0.001), and younger hens produced eggs with higher ovotransferrin (P < 0.05) and ovalbumin content (P < 0.01). The data from the study show that the evaluated factors and their interactions significantly affected the physical parameters of the eggs, whereas albumen functional properties and lysozymes, ovalbumin, and ovotransferrin were negligibly affected.