MVSc

In this investigation the pathological effects of aflatoxicosis and
permissible levels of aflatoxin were studied at different dose levels viz. 5ppb,
10ppb, 20ppb and 40ppb. In the aflatoxin fed ducks, reduced feed intake and
diarrhoea were noticed. There was a significant reduction in the body weight
and carcass weight which were indicative of the toxic injury to the
gastrointestinal tract. There was a significant increase in the liver weight
reflecting the damage to the hepatic system.
There was reduction in the haemoglobin concentration, total erythrocyte
count, packed cell volume and significant increase in the erythrocyte
sedimentation rate indicating the adverse effect of aflatoxin on the
haemopoietic system. Leucocytosis with heterophilia and lymphopenia were
observed suggesting the deleterious effect of aflatoxin on the lymphoid organs.
Highly significant reduction in serum total protein, albumin values, AlG
ratio and significant increase in globulin were observed indicating hepatic
damage.
Grossly, the aflatoxin fed birds showed pale enlarged liver, focal
necrotic areas, subcapsular haemorrhage, fatty liver, greenish discolotation
and surface granularity and nodularity of varying intensity depending on the
dose and duration of the treatment. In the kidney and spleen, mild congestion
were observed. Bursa showed atrophic changes.
Histopathological alterations in the liver consisted of biliary
hyperplasia, fatty changes, congestion of the hepatic sinusoids portal venous

congestion, portal fibrosis, focal collection of mononuclear cells, dissociation
of hepatocytes, hepatocytomegaly and fibrous tissue proliferation of varying
intensity depending on the dose and duration of the treatment.
In the spleen, congestion, vascular sclerosis and depletion of
Iymphocytes in the cortical and paracortical areas were noticed, whereas in
the kidney besides nephrosis, mild peritubular accumulation of mononuclear
cell were noticed at 20ppb level of aflatoxin while tubular degeneration,
swelling of the tubular epithelium, mild fibroblastic proliferation with cellular
infiltration in the interstitium were noticed at 40ppb level.
Generally, bursa of fabricius of the treated birds revealed lymphoid
depletion in the follicles, interfollicular edema and proliferation of interfollicular
connective tissue.
Aflatoxin treated groups showed dose and duration dependant degrees
of ultra structural changes. The ultrastructural changes noticed were intact cell
nucleus with prominent nuclear pores, increased amounts of heterochromatin
that appeared as clumps, dilatation and degranulation of rough endoplasmic
reticulum (RER), rounded, oval or elongated mitochondria which were either
normal or swollen containing swollen cristae along with the presence of
electron dense material within the matrix, smooth endoplasmic reticulum (SER)
that appeared as small tortuous vesiculated structures and scattered lipid
droplets.
Aflatoxin B1(AFB1) residues were detected in the liver, muscle pooled
samples of th.e kidney and blood of birds maintained with feeds containing

• aflatoxin at levels of 20 and 40 ppb during the fourth, sixth and eighth month.
No residual toxin could be detected in birds treated with aflatoxin at a level of
5ppbthroughout the experiment. At dose level of 10ppb, no AFB1 residues
could be detected by the second and fourth month, but during the sixth and
eighth month negligible amount of residues could be detected in the liver and
muscle.
This study highlights the pathological effects of aflatoxicosis in ducks.
Moreover, the adverse effects on the hepatic, haemopoietic and renal systems
could be documented. By considering the above facts aflatoxin level of 10ppb
is fixed as permissible level in ducks. However, permissible level can vary
with the season, diseased conditions of the bird and storage practices of feed.
Therefore, this study emphasizes the need for regular screening of feed for
aflatoxin content.