Poultry Judging Practice Test

The yolk is the primary source of nutrition for an embryo during embryogenesis. It serves as the reservoir of nutrients that are essential for the growth and development of the embryo. The yolk contains proteins, fats, vitamins, and minerals, which provide the necessary energy and building blocks for cellular development as the embryo grows within the egg.

During the incubation period, the embryo utilizes the nutrients present in the yolk by absorbing them through the vitelline membrane, which separates the yolk from the other parts of the egg. This nutrient-rich environment is crucial for the successful development and hatching of the chick.

Other parts of the egg, such as albumen, which is primarily water and protein, play supporting roles but do not provide the concentrated nutrition that the yolk does. The shell membrane acts as a protective barrier, and the chalaza helps keep the yolk in place but is not a source of nutrition. Overall, the yolk's rich nutrient composition makes it indispensable for embryonic development.