Quality tests on hen eggs produced in laying batteries and in fold units

Abstract
1. Two groups of Rhode Island Red × Light Sussex pullets were housed respectively in batteries and in a fold unit. 2. Samples of the eggs produced were collected monthly and weights of egg fractions, quality tests on yolk and thick white, and porosity coefficients were determined. 3. The tests were continued for a 9-month period and no consistent differences were found in the quality of the eggs produced under the two systems of housing. 4. Colours of yolks produced by battery pullets were paler than those produced in the fold unit on grass. Yolk colour was improved by increasing the proportion of grass meal in the diet of battery birds.