Quality of Eggs, Concentration of Lysozyme in Albumen, and Fatty Acids in Yolk in Relation to Blue Lupin-Rich Diet and Production Cycle.

In recent years, the interest in lupin seeds as a source of protein in poultry nutrition has increased. The aim of this study was to assess the quality of table eggs produced by hens that were fed diets containing pea seeds and various levels of narrow-leafed lupin as a substitute for soybean meal. The share of lupin seeds in the treatment groups was 10%, 15%, 20% and 25%. Egg morphology, the fatty acid profile in egg yolk and the amount and activity of lysozyme in egg white were analysed. Results show that using 10-20% lupin seeds in feed in the diet of laying hens in intensive farming does not result in a change in weight or egg structure, their physical properties or their morphological composition. Increasing the share of lupin seeds in feed for laying hens increases the saturation of the colour of egg yolks, which is a desirable feature among consumers. The use of lupin seeds in feed for laying hens does not adversely affect the chemical properties of egg proteins, as expressed by the amount and activity of lysozyme. In feed for laying hens, replacing soybean meal with lupin seeds has a positive effect on the fatty acid profile in egg yolk (omega-3 and -6 polyunsaturated acids and hypocholesterolemic acids).