For this study the jejuni of 50 adult (2-4 years), apparently healthy Iranian river buffaloes were collected
from the abattoir for gross morphology, histomorphology, and histomorphometry. Our statistical analysis
revealed that, there are significant (P<0.001) differences in the lengths, external diameters, internal
diameters, external circumferences, internal circumferences as well as wall thicknesses of jejunum between
all of the animals under study. Our macroscopic investigations also revealed that, in these buffaloes, jejunal
Peyer’s patches (jejpp) are not grossly visible in the mucosa of this part of gut. The histomorphology of
submucosa revealed a pear shaped jejpp through the whole length of the jejuni at mesenteric as well as
antimesenteric parts. The distributions of the jejpp in the middle and posterior parts of guts were greater than in the anterior part. The mean thickness of the mucosal glandular region was highly significant (P<0.001) between the anterior, middle, and posterior regions. There were no significant differences (P>0.05) in lengths as well as thicknesses of jejunal villi between the 3 different regions. The mast cells distributions were highly significant (P<0.001) between the superficial and deep regions of jejunal tunicae mucosae in all buffaloes. There were also highly significant (P<0.001) differences in the distribution of goblet cells between the superficial and deep regions of jejunal mucosa, and their population was more in the superficial than in the deep region.