2.9. Intestine Morphometric Measurements

Formalin-preserved terminal ileal segments were used to determine villus height, crypt depth, villus height to crypt depth ratio (VH:CD ratio) and total mucosa thickness. Hematoxylin-eosin stain was carried out on 18 samples (n = 3 birds per treatment) [48]. Zeiss SteREO V8 (Carl Zeiss, Jena, Germany) microscope paired with a Zeiss Camera (Carl Zeiss, Jena, Germany) were used to capture images of stained segments. Photos were evaluated by Adobe Photoshop CC version 19.1.6 software. Height of villus was determined from the tip of the villus to the top of the lamina propria, the depth of the crypt was determined from the villus-crypt axis to the base of crypt and total mucosa thickness was measured from the top of the villus to the wall of intestine including villus height, crypt depth and muscolaris mucosa [49].