Shell Quality Parameters of Japanese Quail ( <scp> <i>Coturnix japonica</i> </scp> ) Eggs as Estimated by Non‐Destructive Testing Technology

ABSTRACT The quality parameters of quail eggshells find extensive utility in studies of production efficiency and basic biology. Non‐destructive evaluation methods are of particular relevance. Herein, we developed a non‐destructive technology for assaying such shell characteristics as shell strength ( F ), thickness ( T ), and weight ( W s ). Studies were conducted using 176 eggs laid by 11‐month‐old quails from a resource population of F 2 crossbreds. The main set of measured and calculated parameters included egg weight ( W ), volume ( V ), and surface area ( S ). In addition, we determined an indicator of elastic shell deformation under a non‐destructive load of 0.5 kg ( δ 0.5 ). Use of this parameter set allowed us to make the most accurate non‐invasive prediction of the values of F ( R = 0.756), T ( R = 0.266), and W s ( R = 0.450) for quail eggs. As a result of comparative analysis of the current and previously obtained equations for calculating W s , the disadvantages of using empirical equations were also identified. Herewith, we proposed the so‐called index approach to forming mathematical dependences, simplifying their further use, for example, in breeding studies. As such, we selected the following conditionally called indices: metabolism index ( S / V ) and specific elastic shell deformation ( δ 0.5 / W ). Following the approximation, more convenient and compact dependences were produced. The correlation coefficients between the true and computed values were 0.749 for predicting F , 0.262 for T , and 0.443 for W s , with corresponding RMSE values equal to 0.416 for F , 0.019 for T , and 0.105 for W s . The established index representation of empirical equations will serve as a crucial instrument for eggshell quality control and application in quail breeding.