Goose Embryonic Development, Glucose and Thyroid Hormone Concentrations, and Eggshell Features Depend on Female Age and Laying Period

This study aimed to evaluate embryonic development; analyze the glucose, triiodothyronine (T3), and thyroxine (T4) concentrations in the blood of embryos and goslings; and assess the structure and temperature (EST) of the eggshell. The eggs that were analyzed were from four laying seasons of White Kołuda® geese at three periods (90 eggs × 4 groups × 3 periods). The different embryo proportions, fetal membranes in the egg, and sizes of internal organs indicate a different growth rate and degree of embryo development depending on the laying age and laying period. The goose age influenced the hormone concentrations in the embryos’ blood on the 28th day of incubation, which supports a relationship between the females’ age and development. The eggshell thickness and density change depending on the laying age and the laying period. A decrease in eggshell thickness in the eggs up to the third season was found after the 16th day of incubation (simultaneously, the density showed an increasing trend). A lower EST distinguished the eggs from the oldest geese in the first half of the hatch. The formation of the chorioallantois membrane was associated with an increase in EST in the oldest geese

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)