| Dissertation note |
Mycotoxins are secondary metabolite toxins produced by fungi in or on grains, cereals and nuts used as feed in the poultry industry. Mycotoxicity in birds has been well documented and its severity increases in combination with other toxins. The study determined synergistic pathological responses in quail chicks when fed different level of Aflatoxin B1 (AFB1) and Ochratoxin A (OTA). A total of 245 quails chicks were divided into seven groups (G1-G7) having 35 quail chicks in each. OTA mixed feed was fed to quail chicks at a dose rate of 1 and 1.5 ppm in G1 and G2 respectively. G3 were fed 2 ppm OTA + 1 ppm AFB1. AFB1 was offered in the feed at a level of 1 and 1.5 ppm in G4 and G5 respectively. G6 birds were fed 2 ppm AFB1 + 1 ppm OTA while G7 acted as a control. All the birds offered toxin free basal diet for first 7 days. Day 7 was considered zero day of experiment. At this day chicks shifted to different groups of 35 each (G1-G7). Group G7 was control group and offered toxin free diet. Birds were monitored twice daily for clinical signs. Randomly selected six birds from each group were slaughtered at day 14, 21, and 28. Blood samples with and without anticoagulant were collected for hematological and biochemical studies respectively. Morbid tissue of liver, kidney, and intestine were collected for histopathological studies. The OTA groups developed anemia manifested by a significant decrease in the red blood cell count, packed cell volume percentage and hemoglobin concentration, while increase erythrocyte sedimentation rate at the end of the experiment all groups showed significant reduction in red blood cell count. This reduction was found to increase with time proportionally to the level of OTA and AFB1 alone or in combination exposure. Clinical signs in chicks administered AFB1 and OTA included depression, decreased feed intake and decreased body weight. Severity in clinical signs was dose related. Pathological lesions in liver of these chicks were hemorrhages, fatty change, centrilobular necrosis and periportal fibrosis. Microscopically, liver showed vacuolation, fatty change, congestion and individual cell necrosis. Kidney of these chicks included pyknotic changes in the epithelium of proximal and distal convoluted tubules. Severe necrotic changes in the collecting ducts and accumulation of pink homogenous material in the lumen of tubules. Intestine showed hemorrhages, edema, degeneration and infiltration of mononuclear cells were observed. OTA damaged intestinal mucosa more severely than AFB1. Serum biochemical study indicated a significant decrease in total serum proteins and increase in urea and creatinine. It is concluded that AFB1 and OTA are capable of inducing hematological and histopathological alterations in quail chicks at higher dietary concentrations, either individually or in combination.
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