Comparison of Hens Producing High Versus Low Quality Egg Shells

Abstract

Two types of hens were selected from several populations for their ability to lay consistently eggs of either low or high specific gravity (SG), the trait commonly used to indicate shell quality. The two types were compared for eight parameters: age at first egg, %-lay, body weights, egg weights, SG, shell thickness, shell shape index, and Haugh units. Of these eight parameters, three showed characteristic differences between the two types of hens: SG, shell thickness and body weight. Hens which consistently laid high SG eggs also had thicker shells and lower body weights than those which laid low SG eggs.