1 گروه علوم دامی، پردیس کشاورزی و منابع طبیعی دانشگاه تهران، کرج- ایران
2 گروه علوم دام و طیور، پردیس ابوریحان دانشگاه تهران، پاکدشت- ایران
3 سازمان دامپزشکی کشور، تهران- ایران
4 صندوق بیمه محصولات کشاورزی، تهران- ایران
عنوان مقاله [English]
BACKGROUND: Poultry production in houses and high stocking density, results in increase in mortality because of different diseases. Objectives: Investigating the effective managerial and environmental factors on mortality in industrialized poultry farms, proportion of each factor and ranking farms based on mortality risk to solve some problems of Iran’s poultry farm insurance. Methods: Samples were taken from 47 broiler, 20 layer and 30 broiler breeder farms of 16 Iranian provinces which were selected based on geographical location, climate and outbreaks of diseases. House characteristics were evaluated by precision measurement. Parameters such as heat exchange, light intensity, atmospheric conditions (inside oxygen and ammonia concentration, acidity and moisture of litter) and quality of equipment (ventilator capacity, heating & cooling systems) were measured. Based on collected data, managerial index was defined and calculated. Parameters related to sanitary condition, birds’ health and immunization were measured by blood anti body titer. A total of 97 poultry farms were included in the investigation and 27231 measurement data were recorded. Results: Average mortality in broiler, layer and breeder farms was 15.4, 11.2 per period and 1.9% per month, respectively. According to stepwise minimum Wilk’s Lambda discriminant regression, the highest standardized coefficient belonged to vaccine accomplishment (VA) followed by house ventilator capacity (VM), immunization against avian influenza (AIG), farm biosecurity (SHOW), drinker type (DRIN), precipitation rate (RAIN) and temperature management index (TMI): Mortality Risk(0,1)=-2.622+1.533 VA-1.135 SHOW+0.739 AIG+0.551 DRIN-0.016 VM+0.003 RAIN+0.002TMI. Main variables of models which were fitted to layer and broiler breeder flocks were health and ventilation. Conclusions: 6 managerial and environmental factors, immunization of flock against diseases, farm biosecurity and house ventilation had the greatest impact on ranking the mortality risk.