The influence of Isa Brown laying hen age on egg quality in humid tropics

Abstract

This study was conducted to evaluate the effect of hen age on internal and external egg quality indices of Isa Brown hen raised in the tropics. The external egg quality indices studied were egg weight, egg length, egg width, shell thickness, shell ratio and shell weight, while the internal egg characteristics were albumen weight, albumen height, albumen ratio, yolk weight, yolk ratio and Haugh unit. A total of 180 eggs were randomly selected and used for this study. The data were taken biweekly (weeks 31, 33, 35, 37 and 39) each age in weeks represented a treatment group. Data obtained from this study were subjected to analysis of variances and the relationship between egg weights with different egg parameters at different ages were determined by correlation analysis. The results obtained indicated that as the hen age increased, albumen weight, yolk weight albumen ratio, egg weight, egg length, shell thickness and shell weight significantly increased (p<0.05). While, albumen height, yolk ratio, Haugh unit and shell ratio were significantly decreased (p<0.05). The correlation coefficient obtained indicated that egg weight had positive correlations with shell thickness (0.869, 0.110, 0.482, 0.336 and 0.329), shell weight (0.286, 0.004, 0.598, 0.336, 0.723) and albumen weight (1.00, 0.480, 1.000, 1.000, 0.728) for weeks 31, 33, 35, 37 and 39, respectively. It was therefore concluded that the age of the birds affects both the external and internal egg characteristics, the older the hen, the lower the albumen height, yolk ratio, Haugh unit and shell ratio egg quality characteristics.