Histochemical investigation of duodenum in quail birds in Iraq

Background: The duodenum represents a critical segment of the small intestine in avian species, playing essential roles in digestion and nutrient absorption. Quail birds (Coturnix coturnix) are economically important poultry species in Iraq, yet comprehensive histochemical studies of their duodenal structure remain limited. Objective: This study aimed to investigate the histochemical characteristics of duodenum in Iraqi quail birds using multiple staining techniques to elucidate structural and functional aspects of this vital organ. Results: H&E staining revealed well-developed intestinal villi with distinct epithelial layers, goblet cells, and underlying lamina propria. Masson's Trichrome demonstrated significant collagen deposition in the submucosa and muscularis layers. PAS staining highlighted abundant glycogen and mucin content in goblet cells and brush border. Morphometric analysis showed mean villus height of 847±52 μm and crypt depth of 198±23 μm. Conclusion: The duodenum of Iraqi quail birds exhibits characteristic histochemical features essential for digestive function, with well-developed structural components that support efficient nutrient absorption and digestion processes.