Formation of immune structures in small intestine of Muscovy ducks (Cairina moschata)

Of particular importance in our time is the detailed study of morphology, physiology and biochemistry, the digestive system of new poultry crosses, which is the biological basis for the development of complete feeding and improving the productive qualities of the bird. The morphological aspects of the formation of the lymphoid structures in the bird’s digestive tract, including Muscovy ducks, have not yet been elucidated. Selected duodenum, jejunum, ileum were filled with subsequent paraffin and stained with hematoxylin-eosin. The study material was selected from non-vaccinated, Muscovy ducks of 1-, 5-, 10-, 15-, 20-, 25-, 30-, 60-, 90-, 120-, 150-, 180-, 210- and 240 days old. In the newborn bird, the immune structures are characterized by a low degree of differentiation and are represented by single lymphocytes. Subsequently, lymphoid nodules appear on the background of diffuse lymphoid tissue from the 30-days-old (in the jejunum intestine) to 60-days-old (in the ileum). In the period from 90- to 120-days-old, lymphoid nodules with centers of reproduction are formed in the mucous membrane of the small intestine. From the age of 120 days-old to the onset of puberty (240 days) in the mucous membrane of all parts of the small intestine, the formation of lymphoid nodules is completed, with centers as well as without germinal center. It has been established that the localization of lymphoid structures of the mucous membrane of the Muscovy ducks’ small intestine has certain regional features: duodenal lymphoid structures are represented solely by single lymphocytes, lymphoid tissue is diffuse and lymphoid nodules are on different differentiation stages, and localized in the mucous and submucous membrane of the small intestine. It was found that lymphoid structures of the jejunum and ileum are represented by Peyer’s patches, which are formed by diffuse lymphoid tissue, single and aggregated lymphoid nodules, and by the general regularity of the lymphoid nodules localization in the mucosal and muscular layer of the organs.