Histomorphometry and histopathology of small and large intestine of fattening lambs fed pomegranate peel treated with tannase producing bacteria

Abstract

Introduction: High concentrations of polyphenolic compounds in plants cause tissue damage,
Erosion of microvilli, and villi shortening. Therefore, the aim of this study was to evaluate the
histomorphometry and histopathology of small and large intestinal tissue of fattening lambs fed
pomegranate peel and pomegranate peel treated with Klebsiella pneumonia as a tannase-producing
bacteria.
Materials & Methods: Fifteen Arabi male lambs with nine or ten months old and initial body
weight of 39.75±7.91kg were used in a completely randomized design with three treatments and
five replicates. Experimental treatments included 1- control diet (without pomegranate peel) 2-
control diet + 20% untreated pomegranate peel, 3- control diet + 20% pomegranate peel treated
with Klebsiella pneumoniae. After slaughtering the lambs, for histological studies, parts of the
duodenum, jejunum, and ileum of the small intestine and large intestine were separated and placed
separately in closed-sealed containers containing 10 Percentage formalin.
Result: The effect of experimental treatments on the feed consumption of the whole period was
significant (P<0.05). Villi height, crypt depth, villi width and villi area in duodenum in treatment
containing untreated pomegranate peel were significantly lower than other treatments (P<0.05).
Thickness of tunica muscularis in the treatment containing untreated pomegranate peel was
significantly higher than other treatments (P<0.05). In the jejunum section, the villi height in the
control treatment was higher than other treatments (P<0.05). Thickness of tunica muscularis in the
treatment containing pomegranate peel treated with bacteria was less than other treatments
(P<0.05). Villus height to crypt depth ratio in the control treatment was significantly higher than
other treatments (P<0.05) and in the treatment containing pomegranate peel treated with bacteria
was more numerically than the treatment containing untreated pomegranate peel. In the ileum
section, thickness of tunica muscularis in the treatment containing pomegranate peel treated with
bacteria was significantly less than other treatments (P<0.05). The severity of inflammation in
different intestinal tissues was reduced in the treatment containing pomegranate peel treated with
bacteria compared to the treatment containing untreated pomegranate peel.
Conclusion: Due to the positive effects of Klebsiella pneumoniae in increase villi height, villi
height to crypt depth ratio in the treatment containing pomegranate peel treated with bacteria
compared to the treatment containing untreated pomegranate peel; reducing inflammatory cells of
eosinophils in the small intestine and reducing the severity of inflammation in the large intestine
for treatment containing pomegranate peel treated with bacteria compared to the treatment
containing untreated pomegranate peel, the use of this bacterium can be recommended to moderate
tannins and other polyphenolic substances in feeds containing tannins.