THE STORAGE QUALITY OF EGGS FROM LAYERS FED WITH THE ADDITION OF VEGETABLE OILS

Abstract

The aim of the study was to evaluate the quality of eggs from laying hens fed with vegetable oils, linseed and soybean, in terms of possible changes occurring during the storage. The material for the study consisted of 270 table eggs from hens fed with standard compound feed (C) and with the addition of linseed oil (L) and soybean oil (S) at a dose of 2.5%. On the day of laying, the zootechnical evaluation of egg quality was carried out (30 per group) and the rest of the eggs were placed in transport crates with the blunt end up and stored at 14 °C and 70% humidity. Analyses of their quality were performed after 14 and 28 days of storage. Characteristics of the whole egg (weight, specific gravity, proportion of morphological elements, air cell depth), shell (weight, colour, breaking strength, thickness, density, water conductivity), albumen (height, Haugh units, weight, pH) and yolk (weight, colour, pH) were evaluated. Regardless of the oil used, there was no variation between groups in egg weight loss, shell water conductivity or air cell depth during storage. The greatest range of yolk weight change was observed in eggs from groups of hens fed with added oils, which may indicate different permeability of vitelline membranes. Albumen quality traits showed no variation according to laying diet. The lightest shells characterised the eggs from hens in group L and the darkest from group C, while after 28 days of storage, the colour of the shells darkened, which was very evident in eggs from group S. Eggs from this group had the most resistant shells at the end of the experiment. It seems that the addition of linseed or soybean oil to laying feed can modify egg quality characteristics at the time of collection, while it does not significantly affect the storage stability of the raw material.