IS THE LAYING HENS REARING SYSTEM RELEVANT FOR TABLE EGGS CHEMICAL AND NUTRITIONAL FEATURES?

Abstract

Do the changes occurred in poultry housing systems affect eggs chemical composition and dietetic parameters? To investigate this hypothesis, we used 700 ISA Brown hens, aged 26 weeks, randomly distributed in two groups: EC group-350 hens accommodated in furnished cages (800 cm²/hen) and FR group-350 hens, reared on deep litter, with access to paddock (9 hens/m²). Same feed (corn-wheat-soymeal) was used in both groups. 100 eggs were collected/group for chemical assessments on edible compounds (yolk, albumen, whole egg), using 20 replicates per parameter and compound. Analytical chemistry was performed via conventional methods, cholesterol through gas-chromatography and caloricity calculated on organic matters energy basis. ANOVA single factor was applied. 100g edible portion of whole eggs in EC group comprised 74.98% water, 1.14% ashes, 12.38% proteins, 10.45% lipids, 1.05% NFE, 174.25 Kcal energy (105 Kcal/egg), 397 µg cholesterol. In FR eggs, water was 75.62%, proteins and ashes didn’t significantly change, lipids and caloricity were lower (9.81%, 168.65 Kcal/100 g; 101 Kcal/egg) and cholesterol was 373 µg. Significant differences occurred between groups for water and lipids content (p<0.05). Although the dietetic value was better in free-range eggs, it must reason if this improvement could counterbalance hygienic threats that could accompany free range production.