| China’s livestock industry development more and more quickly,intensive and high density aquaculture model result in the pathogens increased in the interior of the barn,the diseases of livestock and poultry is also more and more,pathogenic microorganisms have many ways to spread,air is one of the main means of transmission.At present,the research on microbial aerosols in the environment of the farm is focused on the investigation of one or several specific microbes,lack of a quality assessment for overall air of the aquaculture environment and a comprehensive analysis of the microbes contained in the air.This research selects a dairy farm Changchun area as a sample,sampling 1 times per month from September to December,using TSI laser particle counter,Andersen-6 microbial aerosol sampler and SASS 2300 bio-aerosol sampler,to real-time monitoring and sample collection of the ambient air in the cattle farm.The particle size and concentration distribution of aerosol particles,the number of bacteriain this environment were analyzed and elaborated.Research indicates:The results show that the concentration of aerosol particles in dairy cows is closely related to environmental factors.The changes of temperature,humidity,wind speed and hygienic condition will directly affect the concentration of aerosol particles.in the four months,the aerosol concentration in December was the highest,and the aerosol concentration was the lowest in October,but the concentration of aerosol particles in the range of particle size in different months is the same.Particle size in 0.3μm ~ 5.0μm accounted for 99.61% of the total particle concentration,the aerosol particles in this range are also the most serious harm to human and animal respiratory systems.In 4 months,the highest concentration of aerobic aerobics in September,the concentration of aerated bacteria was0.91×104CFU/m3~1.36×104CFU/m3,and the percentage of respirable was between 57.12% and 63.62%.The lowest in October,the aerobic concentration of aerated bacteria was 0.84×104CFU/m3~1.18×104CFU/m3,and the range of respirable percentage was 65.88% ~ 69.89%.From the results,there was no direct correlation between aerosol particle concentration and the concentration of aerobic bacteria;In October,although the concentration of culturable bacteria was low,but the number of respirable particles was high and could not be ignored.The results also prove that the traditional concept that the northern semi-open animal homes within the pathogen microbial concentration will be higher claims that the high number of particles does not mean that the pathogenic microbial aerosol particle content must be high.Analysis of the 16 s rDNA and macro genome technology,the dairy house contains 104 strains of bacteria and 150 kinds of bacteria;In this study,108 strains of bacteria were isolated and purified,identified 9 bacteria and 25 kinds of bacteria.The dominant bacteria were: Saprophytic Staphylococcus,Bacillus licheniformis,Staphylococcus and Bacillus subtilis,The proportion of 108 strains was 24.07%,17.59%,12.04%and 9.26%;Dominant strains are:Staphylococcus and Bacillus,the percentages were 44.44% and 41.67%.China’s aquaculture industry is developing rapidly and occupying an important part of agricultural output.The quality of the environment and the monitoring of the types and concentrations of the pathogenic microorganisms contained therein are an important part of the effective control of the occurrence and spread of animal infectious diseases.It is also an important guarantee for ensuring the safety of farmers and livestock products.The results of this study can provide a basic data for the timely understanding of the background of the pathogen of cultured plants,the real-time monitoring of the quality and quantity of pathogenic microorganisms in the air,and the assessment of the potential hazards of pathogens and conditional pathogens.It is also an important basis for effectively preventing the epidemic of airborne infectious diseases,maintaining animal health and improving productivity. |
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