The 3-cm jejunal samples were dehydrated and embedded in paraffin, and then sectioned into 4-m slices, which were then stained with hematoxylin and eosin. Jejunal morphology was examined using a light microscope with a computer-assisted morphometric system (BioScan Optimetric, BioScan Inc., Edmonds, WA, USA.). The villus height (VH) was measuredfrom the villus tip to the valley between individual villus. The crypt depth (CD) was measured from the valley betweenindividual villus to the basolateral membrane. The 10 longest and straightest villi and associated crypts were measuredfrom each segment (Xu et al., 2003; Li et al., 2015).