The monograph analyzes the problem of postnatal morphogenesis of tissue components, immune structures and lymphatic vessels of the stomach of piglets. It is established that the degree of differentiation and specialization of the main structures of the stomach wall in newborn piglets depends on their body weight (conformity of newborn piglets body weight to the breed standard). The results of analysis of the age-related changes of the main components of the porcine stomach wall in early postnatal ontogenesis are presented. The features of growth and development of immune structures of piglets gastric mucosa, lymphatic vessels and gastric lymph nodes during postnatal adaptation are interpretated.For scientists, lecturers and post-graduate students in the field of veterinary medicine, biotechnology and biology.