Morphological changes of the muscovy duckling small intestine during development

The morphology of the small intestine was investigated in Muscovy ducklings before and after the hatching period using light micoscopy. The villi, crypt depth, villi : crypt (V : C) ratio, were measured in embryos on days 24 and 30 of development, on the day of hatching, and in neonates on days 2, 9 and 13 post-hatching. The height, width and perimeter (girth of villi) of small intestinal villi significantly increased with age (P50:05). Villi number (per transverse section of small intestine) decrease from 2 to 13 days post-hatching (P50:05). The crypt depth and width were significantly affected by age from hatching to 2 days of age (P50:05). The number of crypts increased significantly in the duodenum and jejunum between hatching and 9 days of age (P50:05). In the duodenum and jejunum, the V : C ratio peaked at hatching, and decreased from hatching to 2 days of age (P50:05). The parameters of villi and crypt of the small intestine rapidly changed between hatching and 9 days post hatch suggesting that the first week of life is a crucial step in physiological changes.