DETECTION AND CHARACTERIZATION OF MICROBES CAUSING STUNTED GROWTH IN COMMERCIAL BROILERS

The study was conducted to isolate and characterize the microbes causing stunted growth in commercial broilers from Vai-Vai Poultry Farm (Kornai, Katapara, Dinajpur), Israfil Poultry Farm (Basherhat, Dinajpur), Guljar Poultry Farm (North Sibrampur, Dinajpur) and Maa Poultry Farm (Nayanpur, Dinajpur), during the period from January 2011 to July 2011. A total of 158 samples comprising dead birds, sick birds, litter, droppings, poultry feed and drinking water were collected among them 56 (n= 56) positive samples were isolated for this study from commercial broilers and subjected to primary isolation by propagating in nutrient broth followed by culture on selective media– Brilliant Green Agar, Salmonella-Shigella Agar, Eosin Methylene Blue Agar and Sabouraud’s Dextrose Agar media. Gram's staining techniques were performed. Biochemical properties of the isolates were studied and reaction in TSI agar slant was also observed. Among the 56 positive isolates 9 isolates were found positive for Fungi, 37 isolates were found positive for E. coli and 26 isolates were found to be positive for Salmonella spp. that are the casual factors for stunted growth in commercial broilers. Among them 16 isolates were found mixed infection with Salmonella spp. and E. coli also included in both prevalence. The prevalence of Fungi, E. coli and Salmonella spp. were recorded as 16.07%, 66.07% and 46.42% respectively. Among the microbes isolated Escherichia coli was determined as predominant bacteria (66.07%) causing stunted growth in commercial broilers than Salmonella spp. (46.42%) and Fungi (16.07%). Litter and dropping samples were the highest sources of contamination than tracheal swabs. Fungal samples were isolated from feed, litter and drinking water samples and the prevalence of Fungi were recorded as lowest (16.07%) than other microbes causing stunted growth than Escherichia coli (66.07%) and Salmonella spp. (46.42%). DOI: http://dx.doi.org/10.3329/bjvm.v10i1-2.15643