Abstract: There are many reasons for the quality changes of egg. One of the major factors is its respiration, which is closely related to eggshell ultrastructure. In order to determine the relationship between the ultrastructure of eggshell layers and respiratory intensity of eggs, scanning electron microscopic (SEM) images of the eggshell were obtained, and the relevant parameters were obtained by MATLAB software. The relationship between eggshell thickness, effective layer thickness, mammillary layer thickness, the average size of mammillary cones and porosity and respiratory intensity of eggs was studied by SPSS 19.0 software. The experimental results showed that respiration intensity of eggs was significantly negatively correlated with eggshell thickness (R = -0.36, P < 0.05) and effective layer thickness (R = -0.47, P < 0.05) but was significantly positively correlated with the average size of mammillary cones (R = 0.57, P < 0.01) and porosity (R = 0.66, P < 0.01). In addition, there was a low correlation between mammillary layer thickness and respiratory intensity. The higher respiration intensity of eggs, the more rough the surface of eggshell. Therefore, eggshell thickness, effective layer thickness, the average size of mammillary cones and porosity can pronouncedly affect respiratory intensity of eggs.

Key words: eggshell, ultrastructure, respiration intensity, egg quality