Effect of laying hens age and housing system on physicochemical characteristics of eggs

In this study, the objective was to evaluate the effect of the age of Hy-line Brown hens – 44 and 60 weeks of age (26 and 42 weeks of laying) and housing system (enriched cages and litter) on the quality of eggs. According to our results, eggs with a better quality of albumen were obtained from younger hens than from older hens. Moreover, older hens produced eggs with inferior quality related to shell parameters, such as greater elastic deformation, poorer breaking strength, and thinner shells. However, hens kept in a litter housing system laid eggs with superior shell quality characteristics of less flexible and greater breaking strength, even though the thickness, weight, and percentage were similar in both housing systems. In addition, a higher amount and activity of lysozyme were obtained from eggs laid by hens kept in the litter housing system than those obtained from hens kept in cages. The maintenance system and age of birds also had a significant (P≤0.05) effect on the basic chemical composition of eggs, as well as on the proportion of individual elements and fatty acid profile. Taking these results into account, we can conclude that the more valuable characteristics from the morphological and nutritional point of view were observed in eggs obtained from younger Hy-line hens kept in the litter housing system.