Morphological features of the cuticle of hatching eggs of chickens and turkeys subjected to pre-incubation treatment

Abstract

Improving the productivity of poultry, especially egg crosses, depends on the quality of the bioceramic calcite (CaCO3) layers and surface glycoprotein film of the egg (cuticle). These are the barriers that control the flow of gases and water vapor. Any disruptions in the transport process can lead to a significant reduction in egg hatchability. It has been proven that treatment of chicken and turkey eggs with acid solutions (acetic acid or hydrochloric acid) and sodium hypochlorite prior to hatching has increased egg hatchability compared to the control. In view of this, the aim of this study was to investigate the protective structures of incubation eggs of chickens and turkeys using non-destructive electron microscopic methods and computer processing of digital images of the cuticle coatings of these eggs for reliable prediction of the degree of increase in gas permeability of the cuticle-shell system due to the destructive effect of various chemicals, including disinfectants, for pre-hatching egg treatment. In the experiments, hatching eggs of Leghorn White hens (n = 90) 15–20 weeks of laying and Broad Breasted White turkeys (n = 80) were used. The antimicrobial agents used in the experiments were a 0.6% solution (0.08 mol/L) of sodium hypochlorite, a 2.5% solution (0.4 mol/L) of acetic acid, and a 5.0% solution (1.40 mol/L) of hydrochloric acid. Using the computer analysis of digital electron microscopic images of the egg surface with the software packages Visilog and FemtoScan Online, it was experimentally proved that the destructive effect of these substances on the cuticle-shell system increases in the range of sodium hypochlorite < hydrochloric acid < acetic acid, which positively correlates with the gas permeability of hatching eggs of chickens and turkeys and the egg hatchability index. The presence of fundamentally different morphological features and correlations of the cuticle of chicken and turkey eggs in response to the action of acids and oxidants used for pre-hatching treatment was shown. The digital markers of the cuticle-shell system state, obtained from analytical programs of digital images, have been established, which makes it possible to reliably predict the indicators of increasing the hatchability of chicken and turkey eggs under the conditions of using certain chemicals. The prospect of further research is to study the effect of modern complex antimicrobial agents on the hatchability of poultry eggs of different species.