Immunopathological response of pigs In aflatoxicosis

Abstract

The immune response of pigs fed aflatoxin at two different dose levels. 0.1 and 0.2 mg/kg body weight was studied. The reduction in weight gain observed in the aflatoxin fed pigs was associated with decreased feed consumption and total serum protein concentration. There was increase in ESR and decease in PCV, haemoglobin and total erythrocyte count in the toxin fed groups. The neutrophilic and lymphocytic count did not show any significant variation except when the animals contracted mange infection. Following infection there was slight neutrophilia. The cell-mediated immune response was assessed employing ANAE, PHA and DNCB as markers. A decrease in the immune response was documented in the aflatoxin fed pigs. The humoral immune response was found to be suppressed as evidenced by a decrease in the concentration of total serum protein and gammaglobulin in the toxin fed groups. The phagocytic activity of neutrophils and macrophages was assessed using Nitroblue tetrazolium (NBT) test. The data revealed a decreased phagocytic activity. Haemorrhages were seen in almost all the visceral organs.The liver of aflatoxin fed animals was enlarged and icteric. The gall bladder was distended and oedematous. Fetty change centrilobular necrosis, haemorrhage, bilary hyperplasia, fibrous tissue proliferation, reticular collapse and focal lymphocytic infilteration were the characteristic histological features. Haemorrhage and haemosiderosis evident in the spleen. Tubular degeneration and focal haemorrhages were seen in the kidney. The thymus and the lymphnodes revealed depletion of lymphoid cells and focal areas of haemorrhage. Some of the lymphnodes revealed reactive proliferative response. Regular screening of feed for aflatoxin was advocated as a routine farm operation to prevent the deleterious effect of aflatoxin on the health and productivity of pigs.