The effects of housing system and storage length on the quality of eggs produced by two lines of laying hens

Abstract

Effects of housing systems and storage length on the quality of eggs produced from white and brown layer hens were studied. Egg samples were randomly collected from deep litter and free-range layer systems and stored in a none-air flow refrigerator for the periods of 1, 5, 8, 12, 16 and 20 days at 8 degrees C and 70-80% relative humidity. Specific gravity, pH, albumen index, Haugh unit score, yolk index and yolk colors of the eggs were affected by storage length (P<0.05-0.01). Egg yolk color was only affected by housing systems (P < 0.01), however, egg weight, egg specific gravity, pH, albumen width, Haugh unit, yolk height and yolk color were affected by strains of hens (P<0.05-0.01). As a conclusion, extending storage length affects egg albumen quality more than egg yolk quality. Especially, a sharper decrease was observed after the 12(th) day. This determined time can be used as a threshold for both hatching and market eggs.