We investigated how the geometrical and mechanical properties of eggshell of Japanese quail are affected by strain and flock age. Two strains of quail (white and gray) were used in the current experiment. The results showed that there was no significant difference for all geometric measurements due to strain effect. Eggs produced from the older birds showed significantly higher (P < 0.01) values compared with younger age for all studied traits. Eggs produced from quails at 22 weeks had a significantly (P < 0.01) darker yolk color than that of the younger age. Superiority in shell thickness, shell weight, and breaking force was detected in eggs of gray quails compared with white quails. On the other hand, the eggs from white quails had significantly higher values for static stiffness and Young's modulus as compared with those of gray counterparts. A significant decrease (P < 0.01) was found for fracture toughness and Young's modulus in eggs of aged birds. A significant negative relationship was found between the breaking force and both static stiffness and Young's modulus. A significant positive relationship was observed between breaking force and both shell thickness and shell percentage. The phenotypic correlation between eggshell breaking force and toughness was relatively high.

中文翻译：

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品系和群龄对日本鹌鹑蛋几何和力学特性的影响

我们调查了日本鹌鹑蛋壳的几何和机械特性如何受菌株和鸡群年龄的影响。在当前实验中使用了两种鹌鹑（白色和灰色）。结果表明，由于应变效应，所有几何测量值均无显着差异。 对于所有研究性状，与较年轻的鸟相比，年长鸟产下的蛋显示出显着更高的值 ( P < 0.01)。鹌鹑在 22 周龄时产下的蛋具有显着的 ( P < 0.01) 蛋黄颜色比年轻时更深。与白鹌鹑相比，灰鹌鹑蛋在壳厚度、壳重量和破断力方面具有优势。另一方面，与灰色鹌鹑蛋相比，白鹌鹑蛋的静态刚度和杨氏模量值明显更高。 发现老年禽蛋的断裂韧性和杨氏模量显着降低 ( P < 0.01)。在断裂力与静态刚度和杨氏模量之间发现了显着的负相关关系。在破断力与壳厚度和壳百分比之间观察到显着的正相关关系。蛋壳破壁力与韧性的表型相关性较高。