Analysis of the relations between some physicalindicators of market eggs

The paper discusses the relations between some physical indicators of market eggs of laying hens housed in conventional and enriched cage batteries. The measured results were evaluated by the multiple regression dependence method. They show that in the case of both the conventional as well as the enriched cages a statistically significant dependence exists between the eggshell deflection (dependent variable) and thickness, or the force needed for the eggshell destruction (independent variable). The respective P values are given in brackets (0.002 < 0.05; 0.03 < 0.05; 1.16 × 10-10 < 0.05; 8.31 × 10-4 < 0.05); in the case of the conventional cage and enriched cage also a statistically significant dependence existed (3.81 × 10-91 < 0.05; 3.86 × 10-81; 1.27 × 10-97 < 0.05; 3.46 × 10-57 < 0.05) between the shell weight (dependent variable) and shell thickness, or egg weight (independent variable); in the conventional cage, statistical dependence also occurred between the eggshell weight and egg shape index, (1.07 × 10-6 < 0.05), in the enriched cage this was on the verge of statistical significance (0.062 > 0.05); if in the conventional cage the eggshell thickness was increased by 1 mm, the shell deflection decreased by 0.08 mm,and if the force necessary for the eggshell destruction was increased by 1 N, the shell deflection decreased by 0.0003 mm; if in the conventional cage the shell thickness was increased by 1 mm, the shell weight increasee by 15.509 g and if the egg weight was increased by 1 g, the shell weight increased by 0.061 g. Our work brings further knowledge concerning the monitored characteristics and their mutual relations.