Histopathological and electron microscopic changes in T-2 toxicosis in broiler chicks

The effect of dietary T-2 toxin in broilers at graded concentration from 0 to 42^nd day of age was studied. Feed refusal, reduced activity, watery droppings, abnormal feathering and oral lesions were characteristic symptoms produced by T-2 toxicosis and effect was dose dependent. Ulcers in oral cavity and crop with atrophy of lymphoid organs were the gross lesions produced by T-2 toxin. Loss of tongue papillae and hydropic degeneration with formation of ulcers in the epithelium was the microscopic lesions produced by T-2 toxin in the upper alimentary tract. Degenerative changes, necrosis, and proliferation of Kupffer's cells in liver while degenerative changes in tubular epithelial cells were constant observations in T-2 toxicated birds. T-2 toxin induced dose dependent depletion of lymphoid population in medulla of thymus, bursa and germinal centers of spleen. Scanning and transmission electron microscopy (SEM & TEM) of tongue, oesophagus, crop and thymus, bursa of Fabricius and spleen were also performed. SEM examination of tongue revealed loss of papillae and ulcers on epithelium of oesophagus and crop. In T-2 toxicated birds, damage to cell membrane, endoplasmic reticulum, mitochondria, folds in nuclear membrane and cell apoptosis in the lymphoid tissues were recorded. The results suggested that T-2 toxin induced toxicity in broilers was due to poor utilization of feed, ulcerative lesions in alimentary mucosa and apoptic changes in lymphoid organs.