Abstract

The objective of the present study was to assess the effects of T-2 mycotoxin at dose level of 2 ppm in association with infectious bronchitis virus (IBV) infection on growth performance and clinical signs of broiler chickens. A total of 128 one-week-old chicks were classified into four groups and were treated respectively with T-2 toxin alone, IBV alone, T-2 toxin and co-infected with IBV, and untreated (control) for a period of 6 weeks. The treatment groups exhibited variable degrees of dullness, lethargy, and dehydration, intensity of which increased with duration of treatment. The T-2 toxicated birds, in addition, showed thin and haemorrhagic droppings. The birds treated with T-2+IBV exhibited severe weakness, recumbency, extending and dragging of neck on the ground and gasping (respiratory distress) at 48 h post IBV infection. Characteristic ruffled, thin shafted, uneven and fewer hairs of feathers were also noticed in almost all toxicated birds. Body weights were lower in toxin groups since 2^nd week of toxin feeding. In IBV groups, however, birds did not show much difference from control, but it was higher than toxin groups. The mean percent body weight gains (BWG) and feed conversion ratios (FCR) in all treatment groups were significantly reduced from 3 weeks of toxin feeding or 3^rd day post infection (DPI) onwards.

Key words: Broiler chickens, growth performance, clinical signs, feather, IBV, T-2 toxin.