Knowledge of Chemical Indicators of Eggs from Hens Reared in Conventional and Free Range System

Lucia Iuliana Cotfas, Aida Albu, Marius Giorgi Usturoi


Introduction Many consumers prefer nowadays eggs from alternative production systems because of their concerns about its own food safety and welfare of laying hens (Anderson. K. E., 2009).

According to the regulations, a free range egg is obtained in poultry farms were laying hens have access to outdoor paddock, where they can show all the instincts of physiological and ethological (Usturoi M.G., 2004).

Aims: The aim of this research was the correct information on the quality of these products and comparative study of chemical characteristics of eggs obtain from different production systems (conventional and free range).

Materials and Methods: Chemical indicators’ determination was made through specific methods, in according with actual standards and consists in establishing of water, proteins, fats, ash and non-nitrogenous extractive substances contents. The biological material was represented by 90 eggs produced by Lohmann Brown laying hens aged 33 weeks: 45 gathered from birds exploited in free range system and 45 from birds reared in cages agreed by EU.

Results: Egg obtained from free range system have a slightly higher content of protein (10.35±0.12 % vs. 9.97±0.03 %) compared with conventional system, from albumen and from yolk (17.46±0.00 % vs. 17.19±0.01 %), this fact was happened because of aport of green grass from the outside paddock (Morris T.R., 2004). Comparative with conventional system, eggs from free range system have a higher content of lipids of yolk with 2.23%.Chemical analysis of melange from studied eggs showed a higher rate of dry matter at free range eggs (23.374% vs. 22.969%), but also for proteins (12.952% vs. 12.520%) and lipids (7.676% vs. 7.398%).

Conclusions: The increase in freedom of laying hens (free range) caused a qualitative improvement of dry components of both the egg components (yolk and albumen) but also the quantitative one, and eggs obtained has a high nutritional value



Keywords: chemical indicators, eggs, quality, welfare

Full Text:



Anderson. K. E, 2009 - Overview of natural and organic production: Looking back to the future. J. Appl. Poultry Research. 18:348–354.

Galiș Anca-Maria, Ilie Van, André Théwis, 2012. Organoleptic, chemical and microbiological quality of table eggs obtained in different exploitation systems for laying hens in Romania, Scientific Papers, Animal Science, Series D, vol. LV CD-ROM ISSN 2285-5769, ISSN-L 2285-5750.

Hidalgo A., Rossi M., Clerici F., Ratti S. 2008. A market study on the quality characteristics of eggs in different housing system. Food Chemistry, 106:1031:1038.

Huopalathi R., Lopez-Fandino R., Anton M., Schade R. (Eds.) 2007. Bioactive Egg Compounds, Springer-Verlag Berlin Heidelberg, p. 1-97.

Matt D.,Veromann E., & Luik A., 2009. Effect of housing system on biochemical composition of chicken eggs, Agronomy Research, 7 (Special Issue II), 662 - 667.

Minelli, G., Sirri, F., Folegatti, E., Meluzzi, A.,& Franchini, A. 2007. Egg quality traits of laying hens reared in organic and conventional systems. Ital. J. Anim. Sci. 58, 518 - 528.

Morris T R, 2004 - Environmental control for layers, World Poultry Science Journal Volume 60 / Issue 02 / June 2004, pp 163-175.

Pickett H. 2007. Alternatives to the barren battery cage for the housing of laying hens in the European Union, Available at:

Radu – Rusu R.M., M.G. Usturoi, Cristina Radu- Rusu, I. Vacaru – Opriș, 2012. Nutritional peculiarities of the hen eggs produced within improved cages or free range alternative systems. Scientific papers - Animal Series, vol 57.

Ternes, W. &Leitsch, S. 1997. Chemestry of egg yolk. In: Proceedings of the VII European Symposium on the Quality of Eggs and Egg Products. Poznan, Poland. WPSA Polish Branch, Poznan, Poland, pp. 127 - 144.

Usturoi M.G.,2004. Production of eggs. Publishing "Ion Ionescu de la Brad" Iasi.

*** - Agriculture Organisation of the United Nations, Rome, Italy. FAO, 2003b. Methods of Food Analysis (chapter 2). Food and Agriculture Organisation of the United

*** - A.O.A.C.. 1990 - Association of Official Analytical Chemists. Food Composition; Additives; Natural Contaminants. vol. II. Cap. 34 – Egg and eggs products.

*** - Technical Paper VELP Scientifica - SER 148 - Determination of the total fat content in whole egg.

*** - SR EN ISO 5983-1: 2006 / AC: 2009 Animal feeding stuffs - Determination of nitrogen content and calculation of crude protein content. Part 1: Kjeldahl method.



  • There are currently no refbacks.

University of Agricultural Sciences and Veterinary Medicine
3-5 Manastur St., 400372 Cluj-Napoca
Tel: +40-264-596.384 | Fax: +40-264-593.792