Pattern of Occurrence of Single and Concurrent Diseases Associated with Mortality in Commercial Chickens in Bangladesh

Abstract

The high mortality rate of commercial poultry has been encountered as a major problem which discourage farmers and entrepreneurs in this industry in Bangladesh. This study was carried out to determine the role of single and concurrent infections associated with mortality in 1751 commercial chickens during one year period from January to December 2002. Diagnosis of diseases was made on the basis of history, necropsy findings, isolation and identification of causative bacteria and other laboratory tests. The etiological investigations of 1751 dead chickens showed that about 39.81% bacterial, 22.73% viral, 13.65% mycoplasmal, 1.54% fungal, 10.11% parasitic, 31.64% systemic, 3.43% nutritional deficiency and 1.77% other diseases were associated with these mortality. Salmonellosis (21.99%), Colibacillosis (8.40%), Fowl cholera (6.52%), Avian mycoplasmosis (13.65%), Infectious bursal disease (11.20%), Newcastle disease (10.34%) and coccidiosis (6.23%) were recognized as major diseases associated with mortality in commercial chickens in Bangladesh. About 32 diseases were recorded, of which both single (76.30%) and mixed infections as two (21.53%), three (1.83%) and four (0.34%) types were associated with mortality of chickens. Significantly (p < 0.01) highest proportionate mortality rate was recorded in > 20 weeks old adult layer (45.52%) in comparison to > 2 to 8 weeks old grower (24.04%), > 8 to 20 weeks old pullet (18.16%) and up to 2 weeks old brooding (12.28%) chickens. Seasonal influence showed highest mortality rate during Summer (43.06%) in comparison to Rainy (27.81%) and Winter (29.13%) seasons. It may be concluded from this study that both the single and concurrent infections are associated with high mortality rate in commercial chickens in Bangladesh. Therefore, the interactions of different pathogens in naturally occurring diseases should be considered during diagnosis and evaluation of vaccination.  Key words: Occurrence; concurrent; mortality; diseases; chickens DOI = 10.3329/bjvm.v1i1.1911 Bangl. J. Vet. Med. (2003). 1 (1) :  15 - 20