Changes in pigment, spectral transmission and element content of pink chicken eggshells with different pigment intensity during incubation.

Yue Yu,Jinming Pan,Zhanming Li

doi:10.7717/peerj.1825

Abstract

Objective. The objective of this study was to investigate changes in pigment, spectral transmission and element content of chicken eggshells with different intensities of pink pigment during the incubation period. We also investigated the effects of the region (small pole, equator and large pole) and pink pigment intensity of the chicken eggshell on the percent transmission of light passing through the chicken eggshells.Method. Eggs of comparable weight from a meat-type breeder (Meihuang) were used, and divided based on three levels of pink pigment (light, medium and dark) in the eggshells. During the incubation (0–21 d), the values of the eggshell pigment (ΔE, L∗, a∗, b∗) were measured. The percent transmission of light for different regions and intensities of eggshell pigmentation was measured by using the visible wavelength range of 380–780 nm.Result. Three measured indicators of eggshell color, ΔE, L∗ and a∗, did not change significantly during incubation. Compared with other regions and pigment intensities, eggshell at the small pole and with light pigmentation intensity showed the highest percent transmission of light. The transmission value varied significantly (P < 0.001) with incubation time. The element analysis of eggshells with different levels of pink pigment showed that the potassium content of the eggshells for all pigment levels decreased significantly during incubation.Conclusion. In summary, pigment intensity and the region of the eggshell influenced the percent transmission of light of eggshell. Differences in the spectral characteristics of different eggshells may influence the effects of photostimulation during the incubation of eggs. All of these results will be applicable for perfecting the design of light intensity for lighted incubation to improve productivity.

Highlights

During the artificial incubation of chicken eggs, five factors are well known to play important roles in embryonic development and are usually carefully controlled: temperature, humidity, partial pressures of oxygen and carbon dioxide, and the frequency of turning eggs (Nelson et al, 2004; Portugal et al, 2014)
The eggs were distributed among three groups according to the pigment intensity of the pink eggshell, i.e., light intensity pigment (LIP), medium intensity pigment (MIP) and dark intensity pigment (DIP)
Our results clearly demonstrate that the intensity of the pigment and the region of the eggshell influenced the spectral characteristics of eggshells, and these results were consistent throughout the incubation

Summary

Introduction

During the artificial incubation of chicken eggs, five factors are well known to play important roles in embryonic development and are usually carefully controlled: temperature, humidity, partial pressures of oxygen and carbon dioxide (ventilation), and the frequency of turning eggs (Nelson et al, 2004; Portugal et al, 2014). Photostimulation during incubation can improve growth and hatchability (Garwood, Thornton & Lowe, 1973; Shafey & Al-Mohsen, 2002; Walter & Voitle, 1972) and decrease incubation time (Fairchild & Christensen, 2000; Ghatpande, Ghatpande & Khan, 1994; Shafey et al, 2002), thereby increasing productivity. Some reports have indicated that photostimulation during incubation reduced or did not affect hatchability (Archer & Mench, 2014; Archer, Shivaprasad & Mench, 2009; Özkan et al, 2012a). Tamimie & Fox (1967) reported a delay in hatchability and increased incidence of embryonic abnormalities in those chicks exposed to light during incubation. Some reports found no effect on hatchability when eggs were exposed to light during incubation (Lauber & Shutze, 1964; Zakaria, 1989)

Methods

Results

Conclusion