عنوان مقاله [English]
Limited information exists on mortality rates and it’s causes on Iranian broiler farms. In the present study, Mortality rate, etiology and risk factors associated with mortality rate in broiler flocks, were evaluated.178 folders related to the mortality of broilers which were covered by the national insurance program for broilers in Mashhad, from 21 March 2011 to 20 March 2012, were investigated. For each case, number and breed of chicks, season of raising, number of death during the entire grow out period and it’s causes, and management factors were recorded. The average of mortality rate in broiler flocks which were inclusive of insurance payment was 23.5% (95%CI: 21.1-25.9%). Most important causes of death were avian influenza and Newcastle disease, respectively. Linear regression analysis revealed that season of raising and presence of disinfectant pool are related to the mortality rate. Flocks which were raised in summer and Autumn experienced 10.4 and 7.2% greater mortality rate than those were raised in winter. Also, farms which used disinfectant pool had 5.7% lower mortality rate than farm did not. Control of environmental effects and improvement of management techniques could prevent disease occurrence and reduce economic losses.