MORPHOGENESIS OF THE WALL OF GLANDULAR PART OF THE STOMACH IN CHICKENS DURING POSTNATAL PERIOD OF ONTOGENESIS

Abstract

Knowledge about the morphological features of the structure and functions of the digestive organs provides the basis for rational and effective use of feed, prevention and treatment of gastrointestinal diseases in poultry. In this regard, the study of the morphogenesis of the digestive system in birds and the mechanisms of their regulation is of great importance. The object of the study was the glandular part of the stomach (proventriculus) in chickens of Shaver 579 strain. The material for macro- and microscopic examinations was selected from birds at age of 1, 30, 60, 90, 120, 150, 180, 210, 240, 270, and 300 days and 1, 2, and 3 years; it was fixed in a 10% neutral formalin solution and embedded into paraffin according to conventional methods. For submicroscopic examinations, the material was selected from hens of this strain at age of 180 days. The structure of epitheliocytes in the superficial epithelium and secretory cells of the deep glands was studied in ultrathin sections. Digital indicators of research results were statistically processed by a personal computer using the Microsoft Excel program. The glandular stomach in chickens is a direct extension of the esophagus and has the form of a thick-walled tube, the wall of which is formed by mucous, muscular, and serous membranes. The superficial epithelium of the mucosa is represented by cylindrical epithelial cells that are located within the basal membrane. They are linked to each other by different types of contacts and have a well-defined polar differentiation. The lobules of the deep glands are formed by cells with well-developed synthesizing organelles and secretory granules. The morphogenesis of the glandular part of the stomach in chickens according to age aspect is manifested by changes in morphometric parameters of the thickness and the area of the membranes of its wall. The wall thickness increases (between the folds 4223.23 ± 189.25 and in the area of the folds 5561.32 ± 45.01 μm) unevenly in chickens up to the age of 240 days. The most developed membrane of the wall of the glandular stomach is the mucosa. Its area increases (by 82.14 ± 0.56%) in chickens up to the age of 180 days, and the area of muscular and serous membranes decreases (by 15.54 ± 0.65 and 2.32 ± 0.33%, respectively). In older birds, the thickness of the wall and the area of the membranes of the glandular stomach do not change significantly

Keywords

• chickens
• stomach
• morphometric parameters
• mucosa
• muscular membrane
• serosa