Developmental morphology of the small intestine of African ostrich chicks

The objective of this study was to investigate the morphological development of the small intestine of African ostrich chicks and to examine the changes in the number of goblet cells therein by observing the gross anatomy and performing histochemistry and morphometry. The BW; length, height, and width of the villi; muscle thickness; depth of the crypts; and number of goblet cells in the intestinal villi and crypts were measured on neonatal d 1, 45, 90, and 334. Our results revealed that the weights of the duodenum, jejunum, and ileum (relative to the BW) peaked on d 90, 45, and 45, respectively, and tended to decline thereafter. The villus height and width and muscle thickness in the small intestine were positively correlated with the age of the birds. The ratio of the villus height to the crypt depth differed among the segments of the small intestine and at the different time points. The number of goblet cells in the intestinal villi and crypts increased rapidly up to postnatal d 45 and then decreased rapidly between d 45 and 90. The number of goblet cells in the villi was greatest in the jejunum on d 1 and in the ileum on d 45, whereas that in the crypt was greatest in the ileum on d 1 and 90 and in the duodenum on d 45. These results suggest that the small intestine develops gradually from postnatal d 1 to 90 and that the period up to postnatal d 45 is marked by significant developmental changes in the parameters reflective of the digestive capacity, such as the weight, length, and surface area of the intestine and the number of goblet cells. Therefore, in reared African ostrich chicks, feed management should be enhanced between postnatal d 1 and 45.