At the end of the experimental period (35 days), one animal
per experimental unit was slaughtered to collect samples
for intestinal histology analysis and for organ morphometry.
Samples 2 cm in length were collected from the duodenum
(15 cm from the pyloric valve of stomach) and the jejunum
(150 cm from ileocecal junction). Four sections (cuts) of
6 μm per sample were prepared in paraffin and colored by
the method of hematoxylin–eosin staining. The villus height,
villus width and crypt depth were then measured in five villi
per section using optical microscopy (AFIP, 1994). The digestive
organs (stomach, pancreas, liver and small intestine) and
the spleen were weighed, and the length of the small intestine
was registered to calculate the weight of the organs in
relation to the fasted body weight and weight:length ratio
of the small intestine.