Hen Age Dependency of Eggshell Refractive Index in Terahertz Frequency

Abstract Eggshell is a natural protective barrier and plays multiple functions for an egg. This study investigated the noble and fundamental biological phenomena of hen age dependency of eggshell optical properties and microstructure using Terahertz spectroscopy and scanning electron microscope (SEM) respectively. SEM was used for taking the cross-sectional ultrastructure image of eggshell. Images were taken with resolution of 256 ⋅ 256 pixels, dimension of 1280 ⋅ 960 pixels and magnification at 1000x. Images were processed to visualize the differences in eggshell structure. In case of younger birds` eggshell, course microstructure, less deep mammillary layer, but wider space between two mammillary cones are found and opposite characteristics were found for older aged birds. The RI (a measure of material density) of the eggshell was significantly ( p -value < 0.05) higher for older hens (2.6) than eggshell from younger hens (2.4). This study might contribute to egg and poultry industry and for better understanding the variations in eggshell in avian protocols and corresponding mother birds’ health and nutritional status for precision egg and poultry production management.