author(s)
Sagar Surjagade, BP Joshi, RA Mathakiya, Bhumi Kapadiya, AP Bansod, AD Jadhao, Ramdatt Prajapati, DJ Ghodasara, CJ Dave and Purnima Jani

abstract
The present study was carried out on broiler birds belonged to different farms and age groups to know the incidence, mortality pattern, gross and microscopic lesions of the E. coli infection. Detection of E. coli infection was done by cultural isolation, staining properties, and biochemical test. The farm wise mortality due to E. coli infection from thirty different flocks varied between 0.92-6.39 percent with an average 2.18 percent. Gross lesions of the nature of fibrin covering on the surface of liver and heart were diagnostic of the disease condition. Histopathologically liver, heart and lung showed multiple areas of focal necrosis, congestion, haemorrhage, oedema and fibrinous thickening along with mononuclear cells infiltration whereas, spleen showed similar lesions like heart, liver and lung with lymphocyte depletion. It is concluded that the colibacillosis is one of the most prevailing condition among broiler birds responsible for heavy economic loss to poultry industry.