Evaluation Of The Developmental Morphology Of The Proventriculus And Ventriculus Of Turkey (Meleagris Gallopavo):- Eleizu, Innocent

ABSTRACT The present study examined gross and microscopic anatomy of the proventriculus and ventriculus of turkey (Jvfeleagrisgallopavo) from 3rd day post-hatch to 98 day post-hatch. Fifty birds were used for the work in order to investigate morphological changes due to age and change in diet. Turkeys aged between 3 and 98 days were sequentially sacrificed and proventriculus and ventriculus were excised from each bird. In addition to noting other gross features, the weight and length of the proventriculus and ventriculus were determined and recorded. Both the proventriculus and ventriculus were prepared for histology using paraffin wax embedding technique. The proventriculus was spindle shaped with slightly enlarged mid-section and the ventriculus was biconcave lens shaped with thickened ridges. The proventriculus and ventriculus showed no variation in shape, although there was rapid change in length and weight in the late post-hatch periods. The mean weight of proventriculus at day 3 was 0.31g and increased to 4.35g at day 98. The mean weight of the ventriculus at day 3 was 2.17g and increased to 53.15g at day 98. The mean length ofthe proventriculus at day 3 was 1.27cm and increased to 2.00cm at day 98. The mean length of the ventriculus at day 3 was 1.53cm and increased to 6.02cm at day 98. Examination ofthe mucosal surface of the proventriculus revealed the presence of circumscribed papillae over the entire surface of the proventriculus and elongated parallel ridges on the ventriculus. The histological structure of the proventriculus was characterized by the presence of long mucosal folds. The folds were lined by simple columnar epithelium. The cores were occupied by lamina propria made of loose connective tissue. The submucosa was strictly occupied by submucosa glands which appeared as lobules separated by thin connective tissue. The glands appeared as compound tubular glands which were closely packed together. Each gland was lined by cuboidal epithelium referred to as oxyntopeptic cells. The tunica muscularis consisted ofthree layers: an internal longitudinal layer, a middle circular layer and an external layer of longitudinal smooth muscle fibres. A thin serosa, surrounded the external surface ofthe tunica muscularis. The laminal surface ofthe mucosa of the ventriculus was covered by koilin which was homogeneously pink stained material and was located over the mucosal epithelium which extended into the lumen ofthe glands giving the impression that koilin was actually secreted by both the surface and glandular epithelial cells of the mucosa. Underneath the glands, there was laminal propria submuscosa made up of dense connective tissue. The tunica muscularis was particularly thick and composed of both longitudinal and circular muscle fibres followed by the serosa which was lined by mesothelium. It appeared that apart from the increase in size, the histological changes remained the same despite the change in diet and nutrition.