摘要：
[目的]探讨冬季地面平养机械通风肉鸡舍微生物含量及分布特征,为构建地面平养肉鸡舍微生物环境调控技术提供支持.[方法]以河南鹤壁某规模化肉鸡养殖场为研究对象,选取7日龄、17日龄、27日龄的肉鸡舍3栋,每栋鸡舍内分别在0,15和160 cm高度布设15个采样点.采用平板自然沉降法对舍内空气微生物进行采样,采用擦拭法采集设施表面微生物样品,采用梯度稀释法和划线法进行计数,利用专用培养基确定主要致病微生物种类,分析舍内微生物含量与环境因子的相关性.[结果]随着日龄的增加,肉鸡舍内微生物含量呈现上升趋势,以17日龄肉鸡舍内的空气微生物含量最大,比7日龄肉鸡舍显著上升了1.13倍(P＜0.05),但与27日龄肉鸡舍无著性差异(P＞0.05).肉鸡舍内空气微生物含量均以进风口端最小,向排风口端呈现出逐渐升高趋势,其中13个采样点空气微生物含量超过畜禽场环境质量标准.肉鸡舍设施表面微生物总菌落数由多到少依次为垫料＞铁质料线＞墙面＞塑料水线＞应急窗玻璃.金黄色葡萄球菌只在垫料中检出.舍内的空气细菌总菌落数与舍内温度、湿度以及粉尘、NH3和CO)2含量呈极显著或显著正相关.[结论]冬季环境条件下,地面平养机械通风肉鸡舍内微生物含量存在超标情况,部分病菌存在于鸡舍空气及垫料中,存在环境感染风险.因此,应做好保温与通风的管理工作,以控制肉鸡舍环境中的微生物水平,降低环境风险.%[Objective] To provide a technical support for microbial environmental control of broiler house,this study discussed the content and distribution characteristics of microbes in floor rearing broiler house with mechanical ventilation in winter.[Method] This study was conducted in a scaled broiler poultry farm at Hebi,Henan.Three houses with broilers at ages of 7,17,and 27 d were selected and 15 sampling spots were set at the heights of 0,15,and 160 cm,respectively.The condition of bacterial pollution in the air of the broiler house was identified using sedimentation plate method.The wiping method was adopted to collect the microbial samples on the surfaces of breeding facilities.Echelon serial dilution and scraping line methods were used to count the numbers of microbes and the species of pathogenic microbes were determined by different selective medium.The correlation of indoor microbial content and environmental factors was analyzed.[Result] The microbial content in house increased with the increase of broiler days.The maximum appeared in the house with broilers at age of 17 d,which was increased by 1.13 times from house with broilers at age of 7 d (P＜0.05).There was no significant difference from the house of broilers at age of 27 d (P＞0.05).The microbial contents increased gradually from the air inlet to the outlet with the minimum at the inlet.There were 13 sampling spots with microbial contents higher than the environmental quality standard of livestock farm.The pathogenic Escherichia coli,Salmonella and Staphylococcus aureus were found in the house air and litter.The total microbial counts were in the order of padding＞iron feed line＞wall＞plastic drinking line＞emergency windowpane.Staphylococcus aureus only existed in the padding.The total microbial content in the house air had significantly positive correlation with the change of house temperature,humidity and concentrations of dust,NH3 and CO2.[Conclusion] In winter,the contents of microbes in floor rearing broiler houses with mechanical ventilation exceeded standard.Some bacteria were found in the house air and litter,with the risk of infectious illnesses.Thus,insulation and ventilation are suggested to reduce microbial contents and environmental risks.
