Effect of pearl guinea fowl eggshell ultrastructure and microstructure on keets hatchability

Krzysztof Damaziak; Agata Marzec; Julia Riedel; Wojciech Wójcik; Paweł Pstrokoński; Hubert Szudrowicz; Dariusz Gozdowski

doi:10.1016/j.psj.2023.102733

Effect of pearl guinea fowl eggshell ultrastructure and microstructure on keets hatchability

Poult Sci. 2023 Jul;102(7):102733. doi: 10.1016/j.psj.2023.102733. Epub 2023 Apr 26.

Authors

Krzysztof Damaziak¹, Agata Marzec², Julia Riedel³, Wojciech Wójcik³, Paweł Pstrokoński³, Hubert Szudrowicz⁴, Dariusz Gozdowski⁵

Affiliations

¹ Department of Animal Breeding, Institute of Animal Sciences, Warsaw University of Life Sciences, Warsaw 02-786, Poland. Electronic address: krzysztof_damaziak@sggw.edu.pl.
² Department of Food Engineering and Process Management, Institute of Food Sciences, Warsaw University of Life Sciences, Warsaw 02-776, Poland.
³ Department of Animal Breeding, Institute of Animal Sciences, Warsaw University of Life Sciences, Warsaw 02-786, Poland.
⁴ Department of Ichthyology and Biotechnology in Aquaculture, Institute of Animal Sciences, Warsaw University of Life Sciences, Warsaw 02-786, Poland.
⁵ Department of Biometry, Faculty of Agriculture and Biology, Institute of Agriculture, Warsaw University of Life Sciences, Warsaw 02-786, Poland.

Abstract

Variability in shell structure is an evolutionary mechanism in birds that enables them to adapt to specific environmental conditions. This variability may also occur within the same species under the influence of individual indicators, such as the age or health status of females. While interspecies variation is quite obvious and easy to interpret, the reasons for intraspecies variation remain unclear. In this study, we examined the ultra- and microstructure of guinea fowl eggshells to identify the association between variations in shell structure and hatchability outcomes. We analyzed the visual differences between shells with low (L), intermediate (I), and high (H) external porosity using scale invariant feature transform analysis with NaturePatternMatch software. We found that the external pore image was closely related to the overall porosity of the shell before incubation. The total pore area, total porosity, and diffusion index (G_H2O) were highest in group H shells (P < 0.001). Posthatching shells were characterized by an increased diameter and total surface area, decreased pore number (P < 0.001), as well as shortened mammillary layer (P < 0.001) and decreased total consumption of mammillary knobs (P < 0.001). The porosity indices of posthatching H shells had intermediate values between L and I. Although the effect of shell structure parameters on hatching was not confirmed, we assumed that all categories (L, I, and H) of shells were ideal for incubation. This suggests that the shell structure adapts to the metabolic rate of developing embryos; however, differences in shell structure affect the duration of incubation and synchronization of hatching. Both L and H shells showed delayed and prolonged hatching. Therefore, we recommended that guinea fowl eggs with different external porosity parameters should be incubated separately for better hatching synchronization. Differences in G_H2O between L, I, and H eggs suggest that the shell porosity characteristics of guinea fowl eggs may be a key determinant of the rate of water loss during storage before incubation.

Keywords: eggshell structure; guinea fowl; hatching egg; porosity.

MeSH terms

Animals
Chickens*
Egg Shell* / chemistry
Egg Shell* / ultrastructure
Female
Galliformes*
Ovum
Water / analysis

Substances

Water