Effects of housing system and age on early stage egg production and quality in commercial laying hens

Abstract

This Study was made to investigate early stage egg production and cracked egg percentage, daily feed intake, feed consumption per produced egg and egg quality traits of a total of 320 hens (Super Nick) from 22 to 38 weeks of age housed in cage (40 experimental units, each containing 4 hens with a surface of 750 cm(2) per bird) and free-range systems (consisting of fixed house and paddock for grazing; 2400 cm(2) floor area with 10 m(2) grazing area per bird). The effect of age on measured traits was investigated with 4 weeks intervals. Four replicates containing each 40 birds were designed for both of free-range and cage systems. The egg production and cracked egg percentage, daily feed intake and feed consumption per produced egg were different between housing systems. Regardless the housing system; daily feed intake and feed intake per produced egg increased, while egg production, cracked egg percentage decreased by the age of layer. Interactions between layer age and housing systems were found significant for egg production, cracked egg percentage, albumen index, albumen pH and haugh unit parameters. Yolk color (P<0.03) was considerably darker and shell thickness was significantly greater (P<0.01) in free-range eggs while albumen pH was significantly higher (P<0.01) in cage group. We concluded that egg production and quality traits were significantly affected by the housing system furthermore, maintaining external and internal egg quality parameters in constant state especially in free-range system appeared to be difficult.