Effects of autosomal recessive gene ( <i>ce</i> ) on quail egg shell properties

1. This study investigated whether the recessive <i>ce</i> gene, which causes the celadon shell colour in Japanese quail eggs and affects the shell structure and quality of both fresh eggs and eggs stored for 28 days at 4°C.2. Analyses were conducted on 54 fresh and 54 stored eggs from four quail groups, including those with typically wild-type shell pigmentation: Jumbo, Pharaoh and Texas, as well as Celadon laying eggs with reduced protoporphyrin (<i>ce</i>). Results included shell weight, ratio of shell to egg weight, shell strength with simultaneous acoustic measurement and shell microstructure using computed microtomography (both 2D and 3D). The quality of fresh and stored eggs was evaluated based on egg weight, yolk weight and proportion (%), yolk index, albumen quality, vitelline membrane strength and elasticity, pH and water activity of yolk and albumen and yolk viscosity. Egg weight (water) loss was measured in stored eggs.3. Celadon eggs had a higher number of shell pores, but the average pore area and its area-equivalent circle diameter were smaller. No differences in eggshell strength were found between Celadon and wild-type pigmented eggs, which was confirmed by acoustogram analysis. Celadon shells displayed a negative Euler number, which indicated strong connections between adjacent pores. This structural enhancement may be an adaptation to compensate for reduced protoporphyrin content.4. Celadon quail eggs were similar in quality to those of the other groups and could be stored with similar results. The greatest weight loss during storage was observed in Texas quail eggs, which exhibited the highest porosity (based on the number and surface area of pores) and the greater morphometric water vapour conductance.