Effect of housing systems on biochemical composition of chicken eggs

The aim of this study was to investigate the impact of production system (organic, conventional) on the quality of chicken eggs. Energetic value, carbohydrate, cholesterol, protein, fatty acid, sodium, potassium, phosphorus, dry matter and vitamin contents were evaluated. The mean content of cholesterol was 30%, and potassium 7%, greater in the organic eggs compared with the conventional eggs. No significant difference was found in the content of fatty acids, protein, sodium or dry matter. The organic eggs had considerably lower contents of calcium (2.8 times) compared with eggs from conventional farming. Negligible differences were found in the occurrence of vitamins (vitamin A, vitamin E, vitamin D3). The residues of 45 pesticides and 6 PCB isomers were analyzed in both types of eggs and no residues compounds were found.