摘要
Abstract
Based on a case of power outage failure in the environmental control system at a large-scale broiler farm in Shangnan County,Shaanxi Province,on March 5,2025,methods such as on-site investigation,personnel interviews and laboratory tests were adopted.It analyzed the incidence of diseased chickens,epidemiological history,pathological characteristics,infection status of viruses including highly pathogenic avian influenza,as well as changes in environmental parameters such as temperature and humidity inside the chicken house,thus revealing the impact of the system failure on the chicken house environment and broiler health.The results showed that a total of 10 800 broilers died in this case,with a mortality rate of 72%.The mortality rates of chickens in the bottom,middle and upper layers of cages were 9.5%,100%and 100%respectively.The power outage lasted for 123 minutes.This flock of broilers had no history of highly pathogenic avian influenza,newcastle disease or other related diseases,and the feeding and management procedures,as well as the sources of feed and drinking water,were all normal.Anatomical findings indicated that the skin,combs and wattles of the affected chickens appeared cyanotic;the tracheas were congested,hemorrhagic and filled with mucus;the lungs and livers suffered from severe congestion and edema;the intestinal mucosa was congested and the intestinal walls became thin.Real-time fluorescent quantitative PCR test results showed that the nucleic acid detection results of highly pathogenic avian influenza virus and newcastle disease virus were both negative.Data from the environmental controller demonstrated that after the power outage,the temperature and humidity inside the house increased significantly,the oxygen concentration decreased continuously,and the ammonia concentration accumulated rapidly at the same time.Comprehensive analysis showed that the influence of infectious diseases and poisoning factors could be ruled out for this case.The power outage failure of the environmental control system and the consequent chain physiological and environmental stress were the main causes of the case.Based on the research results,multi-level risk prevention and control strategies can be put forward from the dimensions of technical protection and personnel management,including installing backup power supply systems,adding independent alarm devices,and establishing on-duty or remote monitoring systems.These measures are expected to construct a comprehensive risk management system and provide a reference for improving the safe production level of large-scale broiler farming.关键词
肉鸡养殖/环境控制系统/热应激/负压Key words
broiler farming/environmental control system/heat stress/negative pressure分类
农业科技
