Plant-derived additives in chicken diets as related to physical properties of eggshell

Abstract

The aim of the study was to estimate the impact of the laying hen standard diet with the addition of plant-derived preparation on eggshell quality from selected Polish layer hybrids. The experimental layers were divided into three feeding groups (group I – standard diet, group II – standard diet + 5% dried herbs, group III – standard diet + 5% fresh forage). It was shown that the differences in the quality characteristics of eggshell: weight, density and colour were not statistically significant, whereas such differences (p ≤ 0.05) were confirmed in the case of the thickness. In fact the thinnest (324.15 µm) eggshell had laying hens from group I – fed standard diet without plant-derived additives. Difference in comparison to group II was 2.95 µm and in relation with group III – 1.97 µm. Moreover, it was demonstrated that the most durable thus undergoing smallest deformation (27.19 µm) were eggshells from laying hens fed standard diet with the addition of 5% dried herbs (group II). The difference was confirmed statistically (p ≤ 0.05) in relation with group I, that is control group fed only standard diet.