The Organic Matrix Components In The Poultry Calcified Shells And The Correlations Between The Organic Matrix And Eggshell Traits

The calcified eggshell is the main component of poultry eggshell.In addition to a large amount of CaCO₃,the calcified eggshell also contains varieties of organic matrices.The organic matrix in poultry calcified eggshells were simultaneously dissociated into acid-insoluble,water-insoluble,and facultative-soluble?both acid-and water-soluble?components,to understand the organic matrix in different quality?normal and pimpled eggshells?chicken calcified eggshells and in chicken,duck and goose calcified eggshells,and further study the distribution characteristics of organic matrix in the poultry calcified shells and the correlations between organic matrix and shell traits.Moreover,the difference among 3 matrix components of normal chicken calcified eggshells was analyzed by label-free proteomic method,which provided a basis for studying the regulation mechanism of eggshell quality.In order to explore the correlations between eggshell qualities and organic matrix in the calcified shells,some normal and pimpled eggshells were selected for similar egg weight,similar shape and uniform shell thickness.The results showed that:?1?In pimpled eggshells,the percentage contents of all 4 types of matrix?the total matrix,acid-insoluble matrix,water-insoluble matrix,and facultative-soluble matrix?were significantly higher than that in normal eggshells;?2?The amounts of both total matrix and acid-insoluble matrix in individual pimpled calcified shells were high,even though their weight was much lower than a normal eggshell;?3?In both normal and pimpled eggshells,the calcified eggshell weight and shell thickness significantly and positively correlated with the amounts of the total matrix in an individual calcified shell?P<0.05?;?4?In normal eggshells,the shell breaking strength showed no significant correlations with the percentage contents of all 4 groups of matrix and the constituents of 3 matrix components?P>0.05?;but in pimpled eggshells,the shell breaking strength were significantly correlated with not only the percentage contents of water-insoluble matrix and facultative-matrix,but also the constitutions of 3 matrix components?P<0.05?.To understand futher the correlations between eggshell traits and organic matrix in the poultry calcified eggshells,the organic matrix were simultaneously dissociated into 3 matrix components from chicken,duck and goose calcified eggshells.The results showed that:?1?To the same poultry,the amount of organic matrix in the calcified eggshell was significantly correlated with shell weight and thickness?P<0.05?;but among cross-species,it was not necessary that the more shell weight and thickness meant the more matrix;?2?It was possible that the matrix constituents of poultries,with closer evolutionary relationships,trended to be more similar;moreover,both major components?acid-insoluble matrix,and water-insoluble matrix?showed no significant correlations with all shell traits?P>0.05?;?3?Among 3 poultries,chicken and duck eggshells showed low breaking strength,percentage contents of 4 types of matrices in both poultries showed no significant correlations with the breaking strength?P>0.05?;however,percentage contents of 4 types of matrices in goose eggshells,with high breaking strength,showed significant correlations with the breaking strength?P<0.05?.Finally,the experiment used label-free proteomic method to compare the proteomics among 3matrix components.The results showed that 600 proteins were identified from 3 matrix components,of which 266?44.3%?proteins were triply shared among 3 matrix components.On the other hand,there was a high similarity among 3 matrix components's common proteomes in normal chicken calcified shells,and the triply overlapped common proteins formed a predominant contributor for the proteomic abundance of any matrix fraction.