Mode bx5

The segment of mid-jejunum (~2 to 3 cm) was taken from euthanized 3 birds per replicate on days 21 and 42. The whole jejunum was located between endpoint of the duodenal loop and the Meckel’s diverticulum. The intestinal tissue was flushed and immediately fixed in 10% formaldehyde solution, followed by tacking in paraffin wax [6 (link)]. Afterward, fixed intestinal samples were placed on a glass slide and then stained using hematoxylin and eosin. Villus height (VH), villus width (VW) and crypt depth (CD) were measured using a light microscope at 100× magnification (Mode BX5; Olympus, Tokyo, Japan). These data were calculated for the villus height to crypt depth (VH:CD) ratio and villus surface area (VSA). VSA was calculated using the following Eq. 2.

The segment of mid-jejunum (~2 to 3 cm) was taken from euthanized 3 birds (the same birds as being used for ileal digestibility) per replicate on days 21 and 42. The whole jejunum was located between endpoint of the duodenal loop and the Meckel’s diverticulum. The intestinal tissue was flushed and immediately fixed in 10% formaldehyde solution, followed by tacking in paraffin wax [19 (link)]. Afterward, fixed intestinal samples were placed on a glass slide and then stained using hematoxylin and eosin. Villus height (VH) and crypt depth (CD) were measured using a light microscope at 100× magnification (Mode BX5; Olympus, Tokyo, Japan). These data were calculated for the villus height to crypt depth (VH:CD) ratio.