Morphological features of immune formations of the avian digestive tract

Immunocompetent structures of the digestive organs play an important role in protecting the body from bacterial and viral infections by providing an immune response. The aim of this study was to establish and summarise the morphological features of these structures in birds of different species, which would allow to determine their morphofunctional status, which is determined by the state of natural resistance and reactivity of the body, and to identify critical periods in the development of the immune system. To achieve this goal, a literature review of current research on the topography and microstructure of immune structures in the digestive organs of birds was conducted. It was established that the material basis of these structures is lymphoid tissue, the differentiation of which has regional characteristics, occurs in a specific sequence and proceeds in several stages. Its development depends on the age, species, sex, type of nutrition of birds and structural and adaptive features of the digestive organs. Immune formations are localised mainly in the mucous membrane of the digestive tract, and in birds of certain species also in the muscular and serous membranes. They consist of T and B lymphocytes and their effector cells, which perform important cellular surveillance functions in protecting the body from foreign genetic information. It has been noted that they are in close contact with macrophages and function as a single lymphoid-macrophage system. The presented scientific research expands and supplements knowledge about the species, breed and morphological features of the structure of immune formations of the digestive tract of birds, which will allow specialists to objectively assess the effectiveness of methods of prevention and treatment of diseases in poultry farms