Post-hatching Development of Ventriculus in Muscovy Duck: Light and Electron Microscopic Study

Abstract

The current study described the developmental sequence of the ventriculus of the post-hatching Muscovy ducks of both sexes ranging from 1-60 days old, by using gross-histomorphometic measurements and by using light microscope, scanning electron microscope and transmission electron microscope. The ventriculus was extended from the level of the 4th intercostal space to terminate behind the last rib at variable distances dependent on the age of the duck. The statistical analysis revealed that the length of the ventriculus from that of the stomach was decreased by the advancement of the age, while the weight was increased. At all developmental age-stages, the cuticula gastrica was composed of two layers; vertical rods and horizontal matrix. The vertical rods projected slightly as dentate processes beyond the surface of the mucosa at 30-60dys old. The type of the gizzard gland was different according to the age; it was simple tubular type lining by one type of cells (chief cells) at 1-15 days old, but were compound-branched type lining by two types of cells; chief and basal cells at 30-60 days old. By semithin sections, the secretory basophilic granules within the cells lining of the tubular glands were increased by ageing. Transmission electron microscopy exhibited that the chief cells had numerous large sizes electron dense and electron lucent secretory granules. In conclusion, there are wide variations in the morphometrical analysis and the structure of the ventriculus at the developmental age-stages of the duck.