Eggshell quality: a comparison between Fayoumi, Gimieizah and Brown Hy-Line strains for mechanical properties and ultrastructure of their eggshells

Abstract

This experiment was designed to study the relationship between mechanical properties and ultrastructure of three genetic groups (Fayoumi, Gimieizah and Brown Hy-Line strains). To assess eggshell mechanical parameters a total of 120 eggs from each strain was used. This study suggested predicting the mechanical properties and ultrastructure of eggshells when egg weight was equal for the three strains (39.8 g). There was a significant difference among strains for shell thickness, eggshell breaking strength and stiffness, with the Fayoumi eggshells recording the highest values compared with other strains. The palisade layer of Gimieizah and Brown Hy-Line eggshells was thinner than that of Fayoumi eggshells. There were significant correlations between palisade length and breaking strength (0.51), shell thickness (0.89) and stiffness (0.48); however, the length of the palisade layer was significantly negatively correlated with elasticity (–0.85). The Fayoumi (local Egyptian strain) showed higher resistance for eggshell breakage than the Hy-Line commercial strain due to their longer palisade layer noting that there were no significant differences in egg weight between the two. The length of the palisade layer plays an important role in eggshell strength, so it is of interest to include these parameters in selection programs aimed to improve eggshell strength. However, a negative correlation between length of palisade layer and elasticity prevented improvement of these two parameters.

Improvement of eggshell quality by dietary N-carbamylglutamate supplementation in laying chickens

“…In addition, hatchability correlates positively with eggshell thickness ( Liao et al., 2013 ). Eggshell structural and textural features that are important for shell strength, such as the density of mammillary knobs, the effective thickness of the mastoid layer, and the width of the mastoid gap, are closely related to eggshell strength ( Radwan, 2015 ). Improved eggshell strength can effectively reduce the loss of eggs in egg marketing activities.…”

The Influence of Hen Aging on Eggshell Ultrastructure and Shell Mineral Components

“…Low density of the mammillary knobs reduces the binding force between the mammillary knob and the eggshell membrane and weakens eggshell strength. In general, the constant size and shape of the mammillary knob and the strong bond between the knobs and the shell membrane resulted in high eggshell strength ( Dunn et al, 2012 ; Radwan, 2016 ). In the classification of mammillary types, Fathi et al (2007) reported that type A mammillary bodies were even in size and distribution and rounded so that there can be maximum attachment to the fibers of the outer membrane.…”

“…Low quality eggshells tend to have an irregular, uneven, or incompletely formed mammillary core arrangement. The mammillary knob abnormalities often are manifested as reduced thickness or increased porosity ( Dunn et al, 2012 ; Radwan, 2016 ). The palisade layer is made of calcite crystals in which an organic matrix is embedded, which accounts for the most of thickness of the eggshell ( Fathi et al, 2007 ; Nys and Gautron, 2007 ).…”

“…Extensive studies were conducted to evaluate the ultrastructural variations in eggshell quality among breeds and species of poultry ( Fathi et al, 2007 ; Radwan, 2016 ). It is well known that the material properties of the eggshell depend on its microstructure and chemical composition, both of which vary through the thickness of the eggshell.…”

Uterine Transcriptome Analysis Reveals mRNA Expression Changes Associated with the Ultrastructure Differences of Eggshell in Young and Aged Laying Hens

“…In the current study, eggshell ultrastructure in aged hens was characterized by thicker mammillary layer, thinner effective layer and less frequency of early fusion. The thickness and proportion of effective layer were the major ultrastructural characteristics determining shell strength and a reduction in its thickness could compromise shell strength conducing to a higher incidence of breakage [25]. Stress concentrations would occur more frequently and rapidly in the site where the fusion of adjacent mammillary columns was delayed or where structural abnormalities arose.…”