Development of the intestinal tract lymphatic system in goats
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Date
1989
Authors
Journal Title
Journal ISSN
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Publisher
Sokoine University of Agriculture
Abstract
Gross and microscopic studies of the Gut-Associated Lymphoid
Tissue (GALT) and Mesenteric Lymph Nodes (MLN) were performed
on ten fifteen 3 months old kids and fifteen
8-12 months old goats.
Morphological changes of the intestinal
tract lymphatic system with age, the relationship of morpholo
gical changes between and within intestinal lymphoid organs in
particular the Peyer's patches and the MLN during growth, possible
role of the Peyer's patches in the immune system of the caprine and
lymph flow from the intestine were studied.
Kids were born with an average of 35 histologically mature
Peyer's patches in the jejunum (Jejunal Peyer's patches-JPP)
which ranged in size from five follicles to 4.5 cm. long patches.
A long Peyer's patch whose width was not uniform was also found in
newborn kids.
j e j unum
It was broader caudally and it extended from the
to the ileocecocolic junction (Jejunal-Ileal Peyer's
Patch-JIPP).
The average length of the JIPP was 0.83 m.
Two
round Peyer's patches were found in the colon (Colon Peyer's
Patches - CPP ).
The Peyer's patches were present on 17% of the
intestine length.
The shape of the follicles and the interfollicular area
breadth were different in the JPP, JIPP and CPP.
Interepithelial
lymphocytes (IEL) number on domes decreased from cranial end
to caudal end of the intestine. The trend was not observed on the
villi epithelium.
Intestinal tract villi epithelial cells in kids which had not suckled were columnar and had their nuclei in
the apices.
In average newborn kids had 5(1— 10) jejunal, 1 (1 - 3)
Their total
ileocecocolic and 3 (2 - 6) colic lymph nodes.
was 0.11% of post-slaughter animal body weight corrected
weight
for stomach compartments weight.
The MLN were immature.
Wi thin
twelve hours after birth and colostrum ingestion, secondary
lymphoid nodules appeared on the MLN.
At three months age, kids had about 38 JPP with size ranging
from five follicles to patches 5.4 cm. long.
The width of the
JIPP was also not uniform, and it was 1.4 tn. long.
There were 2
Peyer's patches were present on about 18% of the intestinal
CPP.
length.
There were 3 (1 - 9) jejunal, 1 (1 - 2) ileocecocolic and
3 (2 - 5 ) colic lymph
nodes.
Their total weight was 0.29% of
the post-slaughter animal body weight corrected for stomach compart-
ments weight.
The MLN were histologically mature.
Goats of 8 - 12 months age had about 33 JPP and 2 CPP.
In a single observation, three snail patches were found in the
cecum.
JIPP had grossly atrophied and measured about 1.5 m.
in length.
Peyer's patches were present on about 13% of the
intestine length.
There were 5 (1 - 12) jejunal, 2 (1 - 4)
ileocecocolic and 4 (2 - 5 ) colic lymph nodes.
Their total
weight was 0.16% of the post-slaughter animal body weight corrected
for stomach compartments weight.
mature.
The MLN were histologically
There was a general trend of a decrease of IEL number on the demes and villi from cr«iiial end to caudal end of the
intestinal tract.
Domes epithelia were columnar and had a mean of
1.2 + 0.3,
1.8 + 0.5 and 0.2 + 0.1 goblet cells per dome in the newborn, 3
IEL nunber on
months and 8-12 months old goats, respectively.
dome and villi showed a general increase with age.
There was no significant difference
(P > 0.05) between the
means of the JPP number of the three age groups.There was
also no significant correlation neither betweenlength of Peyer's
patches and intestine length nor between MLN and body weights.
There was no significant difference ( P >0.05) between the
proportion of intestine on which the Peyer's patches were present
in newborn and 3 months old kids, while there was significant
difference ( P < 0.05) between these two
months old group.
groups and the 8-12
There was significant difference (P < 0.05)
between the means of the MLN weight of the three age groups and
there was also significant difference (P < 0.05 ) between the means
of MLN-body weight proportion of the three age groups.
The JPP, JIPP and CPP had a common character of being
histologically mature at birth, but differed in their follicular
histology and life history.
The JPP follicles were short,
broad and pear-shaped, had large interfollicular areas and did
not show signs of atrophy with age.
The JIPP follicles were
cylindrical or sac-shaped and atrophied with age like the thymus
and avian Bursa of Fabricius.
The atrophy of the JIPP started at the mid portion of the patch. Similarity between the caprine
JIPP and the avian Bursa of Fabricius with regard to their
prenatal maturation, their proximity to the gut and their postnatal
involution is compatible with the assumption that the caprine
JIPP is the equivalent of the avian Bursa Fabricii.
A bean-shaped jejunal lymph node cdudaily located on the
group chain was found in three out of seven animals.
The node
with the single ileocecocolic node drained the JIPP. Efferent
from the bean-shaped jejunal node joined efferent of the ileoce
cocolic lymph node and the vessel formed joined the efferent of the
colic lymph nodes to form the colic trunk.
In three animals,
efferents of one or two colic lymph nodes drained into the
ileocecocolic lymph node.
The colic trunk confluenced with the
jejunal trunk to form the intestinal trunk which emptied into
the cisterna chyli.
Goats did not have visceral trunk.
Description
Dissertation
Keywords
Lymph nodes, Lymphoid tissue, Gross - microscopic studies, Morphological changes