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

Abstract

Simple SummaryEmbryonic development is a crucial issue in the breeding and production of geese. Since geese are kept for four seasons of reproduction, the age of females may affect the development of geese. During incubation, many processes take place inside the egg. With development, organs begin to form, and thyroid hormones and glucose begin to play an essential role in the regulation of these processes. These processes are related to the incubatory conditions and the temperature on the surface of the eggshell. Thus, the eggshell’s physical characteristics can influence a goose’s embryonic development. It was shown that geese’s age (1- to 4-year-old) and laying period (the beginning, the peak, and the end) affect the embryonic development of geese. The concentration of triiodothyronine and thyroxine and the eggshell’s characteristics, including thickness, density, and temperature, were also affected by those factors. This knowledge can support the production of goslings and hatching technology.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.