共查询到20条相似文献，搜索用时 31 毫秒
1.
High levels of dust and microorganisms are known to be associated with animal confinement rearing facilities. Many of the microorganisms are carried by dust particles, thus providing an excellent vector for horizontal disease transmission between birds. Two environmentally controlled rooms containing female broiler breeder pullets (n = 300) were used to evaluate the effectiveness of an electrostatic space charge system (ESCS) in reducing airborne dust and gram-negative bacteria levels over an 8-wk period (starting when the birds were 10 wk old). The ESCS was used to evaluate the effectiveness of reducing airborne microorganism levels by charging airborne dust particles and causing the particles to be attracted to grounded surfaces (i.e., walls, floor, equipment). The use of the ESCS resulted in a 64% mean reduction in gram-negative bacteria. Airborne dust levels were reduced an average of 37% over a 1-wk period in the experimental room compared with the control room on the basis of samples taken every 10 min. The reductions of airborne dust and bacteria in this study are comparable with earlier results obtained with the ESCS in commercial hatching cabinets and experimental caged layer rooms, suggesting the system could also be applied to other types of enclosed animal housing. 相似文献
2.
Commercial hatcheries typically infuse hydrogen peroxide or formaldehyde gas into hatching cabinets to reduce airborne pathogens that may lead to disease transmission during the hatch. A nonchemical option, an electrostatic space charge system (ESCS), was customized for full-sized commercial hatching cabinets and was tested extensively in broiler hatcheries. The ESCS cleans air by transferring a strong negative electrostatic charge to dust and microorganisms that are aerosolized during the hatch and collecting the charged particles on grounded plates or surfaces. In studies with three poultry companies, the ESCS resulted in significant (P < 0.0001) reductions of airborne dust of 77%-79%, in Enterobacteriaceae and fungus levels not significantly different (P > or = 0.05) from those with formaldehyde, and in 93%-96% lower Enterobacteriaceae than with no treatment or with hydrogen peroxide treatment (P < 0.01). The ESCS significantly (P < 0.05) reduced airborne Salmonella by 33%-83% compared with no treatment or hydrogen peroxide treatment. Results of this study suggest that the ESCS is a viable alternative to chemical treatment for reducing airborne pathogens in full-sized commercial hatchers, and it also provides dust control and containment, which should be helpful in reducing cross contamination and loading of ventilation ducts within different areas of the hatchery. 相似文献
3.
Salmonella in birds is a concern because of the human foodborne illness associated with the consumption of poultry meat and eggs. One of the methods of transmission of Salmonella within a flock can be by the air. Therefore, we used reduction of transmission of Salmonella to monitor the effectiveness of the electrostatic space charge system (ESCS). During the average broiler breeder laying cycle of 40 wk, a large amount of dust becomes airborne and accumulates on walls, ceiling, and equipment. Many microorganisms adhere to these dust particles, making dust an excellent vector for horizontal disease transmission between birds.We used two environmentally controlled rooms containing commercial broiler breeders to evaluate the effectiveness of an ESCS that produced a strong negative electrostatic charge to reduce airborne dust and, subsequently, microorganism levels. The ESCS caused the dust to become negatively charged, therefore moving to the grounded floor in the treatment room. The use of the ESCS resulted in a significant reduction (P < 0.0001, 61% reduction) in airborne dust concentration levels, which resulted in a significant reduction (P < 0.0001, 76% reduction) in total airborne bacteria and gram-negative bacteria (48% reduction) in the treatment room. Significant reductions (P < 0.05) of gram-negative bacteria (63% reduction) on the egg collection belts were also recorded in the treatment room, which resulted in a significant reduction (P < 0.0001) of gram-negative bacteria (28% reduction) on the eggshell surface. The ESCS treatment resulted in fewer Salmonella enteritidis-positive hens and their progeny from the treatment room due to reductions of dust and airborne bacteria. In addition, this significant reduction in bacteria on the eggshell surface should result in less bacteria in the day-old chicks, therefore better early chick livability. There was no significant difference (P > 0.05) in egg production, male or female body weights, mortality, or reproductive performance in the ESCS room compared with the control room. 相似文献
4.
《The Journal of Applied Poultry Research》2004,13(2):200-206
The use of chemicals in food plant sanitation for removing and killing microorganisms could be reduced by the use of alternative nonchemical interventions. Supercharged negative air ionizers have shown potential to effectively reduce airborne and surface microorganisms. In our earlier studies, a small chamber, controlled at 85% relative humidity and supercharged with a −25 kV electrostatic space charge system (ESCS), was used to transfer a strong negative charge to bacteria on stainless steel surfaces. The ESCS treatment caused the levels of biofilm bacteria from chicken carcass rinses to be significantly decreased with 99.8% efficiency at a distance of 18 cm with ion densities of 106 negative ions/cm3 or more. In the present study, effects of the −25 kV charge of ESCS on specific pathogens important for food safety were studied. Treatment of Campylobacter jejuni, Escherichia coli, Salmonella enteritidis, Listeria monocytogenes, and Staphylococcus aureus achieved up to a 4 log reduction with 99.9% reduction efficiency in 3 h. Treatment of bacterial spores of Bacillus stearothermophilus achieved up to a 3 log reduction with a 99.8% reduction efficiency in 3 h. These significant reductions for 5 species of pathogenic bacteria and bacterial spores suggest that the ESCS is a promising alternative treatment for reduction of microbial load in a food-processing facility with the potential to reduce the amount of antimicrobials used. 相似文献
5.
Bacteriologic culturing of environmental samples taken from sources such as manure pits and egg belts has been the principal screening tool in programs for identifying commercial laying flocks that have been exposed to Salmonella enteritidis and are thus at risk to produce contaminated eggs. Because airborne dust and aerosols can carry bacteria, air sampling offers a potentially efficient and inexpensive alternative for detecting S. enteritidis in poultry house environments. In the present study, an electrostatic air sampling device was applied to detect S. enteritidis in a room containing experimentally infected, caged laying hens. After oral inoculation of hens with a phage type 13a S. enteritidis strain, air samples were collected onto agar plates with the electrostatic sampling device, an impaction air sampler, and by passive exposure to the settling of aerosols and dust. Even though the floor of the room was cleaned once per week (removing most manure, dust, and feathers), air samples were positive for S. enteritidis for up to 4 wk postinoculation. On the basis of both the number of S. enteritidis colonies observed on incubated agar plates and the frequency of positive results, the efficiency of the electrostatic device was significantly greater than that of the passive exposure plates (especially at short collection intervals) and was similar to that of the far more expensive impaction sampler. The electrostatic device, used for a 3-hr sampling interval, detected airborne S. enteritidis on 75% of agar plates over the 4 wk of the study. 相似文献
6.
《The Journal of Applied Poultry Research》2006,15(3):394-405
Emissions from animal feeding operations have become a growing concern. Although many studies describe occupational exposures and exhaust concentrations associated with animal facilities, very little information has been provided about the ambient air around the houses. This study investigates real-time and primarily 24-h time-integrated levels of particulate matter ≤2.5 μm in diameter inside and outside (up to 500 ft from the house) of commercial tunnel-ventilated broiler houses on a farm in northeast Georgia. None of the 24-h particulate matter measures collected when the houses were tunnel ventilated exceeded the Environmental Protection Agency's 24-h National Ambient Air Quality Standard of 65 μg/m3. 相似文献
7.
《The Journal of Applied Poultry Research》2014,23(4):625-638
In-house windrowing of broiler litter between flocks has been adopted by producers to reduce pathogens and improve litter quality before chick placement. In this study, 5 consecutive windrow trials were conducted in commercial broiler houses for their effect on litter bacterial populations, organic matter stabilization, cumulative ammonia emissions, and nutrient transformation and compared with litter conditioning (tilling) in adjacent houses. No significant reduction ofClostridium spp. andEscherichia coli populations was found in windrowed litter from d 0 to 7. No significant difference of 7-d mortality was found between windrow and nonwindrow houses. The windrowed house resulted in better foot quality than the nonwindrowed house from 1 of 3 scored flocks. Water-soluble phosphorus increased in both windrowed and nonwindrowed litter; therefore, appreciable biotic and abiotic activity occurred in litter with both treatments after flocks were removed. Overall, no negative effect of windrow treatments on litter quality for agronomic applications was observed. Both the control and windrow treatments resulted in a decrease in litter moisture content (2 to 5%) likely beneficial to bird health conditions. High ammonia emissions persisted after windrow spreading; therefore, a need may exist for an extended period of ventilation or a litter amendment as crucial before chick placement. Litter amendment at a low dose was effective in lowering ammonia concentrations after windrowing and was more economical comparing to operating fans in winter conditions. 相似文献
8.
H G Hilliger 《DTW. Deutsche tier?rztliche Wochenschrift》1991,98(7):257-261
The content of airborne dust and germs in animal houses is described qualitatively and quantitatively. After having left the animal house by way of the exhaust air the microorganisms suffer a decay which is caused by dispersion and death-rate. The dispersion can be demonstrated by models. The boundary of the dispersion of germs and dust is about 200 m from source under normal conditions. Epidemiologic studies indicate that some virus particles can be transported over several miles by way of the air. Control of airborne dust and germ levels in animal houses is still poor. 相似文献
9.
1. The natural history of air hygiene in a pullet house was assessed at three-weekly intervals using a combination of in vitro and in vivo assays. The performance of an internal air filter was also examined as an experimental technique for providing clean air. 2. Overall, air hygiene was poor by comparison with occupational standards for human health. The mass concentrations of respirable and inspirable dust were 1.4 and 11.3 mg/m3 compared to human exposure limits of 5 and 10 mg/m3 respectively. The concentration of ammonia was typically about 20 ppm. 3. The majority (greater than 99%) of airborne particles were non-viable. Commensal bacteria from the skin were the most numerous airborne bacteria. Scopulariopsis and Aspergillus spp. were the most prevalent fungi recovered from the air and bird's lungs respectively. The concentrations of airborne and lung fungi were positively correlated with ammonia concentrations. 4. The differences between in vivo and in vitro assays of airborne microorganisms suggest that an aerosol sampler should be devised which better mimics the physical and biochemical environment of the respiratory tract. 相似文献
10.
《The Journal of Applied Poultry Research》2015,24(1):73-79
A study was conducted in South Georgia to assess the carbon footprint of poultry farms. The study included broiler grow-out farms, pullet farms, and breeder farms from one commercial broiler complex. Data collection included the fuel and electricity bills from each farm, house size and age, flock size and number of flocks per year, and manure management. Emissions were calculated using a greenhouse gas (GHG) calculation tool. The carbon dioxide, nitrous oxide, and methane (CH4) emissions were computed and a carbon footprint determined. Carbon footprint comparisons were made based on house construction and age. Based on these results, an evaluation of the mechanical sources of emissions showed that approximately 96% of the emissions from the broiler and pullet farms were from propane use, while only 3.9% of the total mechanical emissions from breeder farms were from propane use. On breeder farms, 83% of mechanical GHG emissions were the result of electricity use, while the pullet and broiler grow-out farms accounted for 2.9 and 2.7%, respectively, of the total mechanical emissions from electricity use. The data collected from the farms and entered into the GHG calculation tool revealed that breeder houses had higher levels of CH4 emissions from manure management when compared to emissions from broiler and pullet houses. Even though the GHG emissions from poultry production farms were minimal compared to other animal production farms, the different sources of emissions were identified, thereby enabling the farmer to target specific areas for mitigation. 相似文献
11.
Biofilters and bioscrubbers are ultimate tools to control odour emissions from animal houses in pig and poultry production. Little is known about the efficiency of these devices to remove airborne particulate pollutants such as dust, microorganisms and endotoxins from the exhaust air of animal houses. Preliminary results of a one year field campaign in two piggeries show that the biofilter reduces the number of particles in the exhaust air by 79 to 96%. The efficiency of the bioscrubber was 22% only. The biofilter reduced the amount of mesophilic bacteria by 11% and 71%, respectively, the amount of thermotolerant fungi by 71%. The concentration of endotoxin and mesophilic fungi in the clean air after the bioscrubber was 3.8 times resp. 2.7 times higher than in the air of the piggery. The washing water which is regularly recirculated in both systems was highly contaminated with varying amounts of air contaminants. It seems that the quality of the washing water distinctly influences the reduction efficiency of both systems. 相似文献
12.
13.
14.
畜禽舍微生物气溶胶向环境扩散的研究 总被引：7，自引：0，他引：7
应用一个扩散模式估算来自畜禽舍的微生物气溶胶向环境的扩散。在此考虑到了较大悬载尘埃颗粒的沉落和气悬状态下细菌生物学活性对空气微生物传播的影响。菌源高度 (栏舍废气排放孔 )认作 3m和 1 0m。当扩散级为IV和菌源强度为 1 0 6CFU/s时 ,在距离畜禽舍 1 0 0 ,2 0 0 ,30 0 ,40 0 ,5 0 0m处细菌含量分别为 5 0 ,1 0 0 ,2 0 0 ,5 0 0和 1 0 0 0CFU/m3。研究证明 ,畜禽舍之间保持一定距离将很大程度地减少气源性感染的威胁 ;畜牧场应建设在距居民区最少 5 0 0m的地方。 相似文献
15.
Our aim in this longitudinal study (covering years from 1996 to 1999) was to use data regularly recorded in a production database, to identify farm- and flock-level factors associated with cumulative mortality in broiler flocks during: (a) the 1st week after housing and (b) the rest of the growout (2nd to 5th week). A total of 1664 broiler flocks kept in 132 broiler farms were included. The average weekly cumulative mortality was 1.54% (95% CI: 1.46, 1.62%) during the 1st week and 0.48% (95% CI: 0.47, 0.49%) during the rest of the growout.The final least-squares regression model of cumulative mortality during the 1st week identified the following significant factors: study year, flock size, stocking density, use of paper underlay for feeding during the 1st week, and the interaction terms between type of ventilation, drinking system and floor insulation. The final model for the 2nd to 5th week demonstrated that the factors age of the broiler house, heating system and control system for the air intake were associated with cumulative mortality, but the effects of the two latter variables were significantly modified by age of the broiler house. A significant difference in mortality between flocks delivered from various hatcheries was found in both analyses.Our results suggest that changes in several housing factors and management routines might reduce the mortality losses, but the relationship depends on the stage of production. 相似文献
16.
试验旨在对商品肉鸡层叠式立体养殖模式的环境参数进行监控,分析不同季节笼养肉鸡环境参数的差异,为科学养殖提供数据支撑。选择规模化肉鸡养殖场的同一栋鸡舍,在秋季和冬季饲养周期中,采用分次多点测量法,连续监测3~6周龄肉鸡舍内温度、湿度和空气质量,测定点均匀分布在舍内4个位置,比较秋季和冬季舍内环境参数的变化。结果显示,在肉鸡生长后期,冬季舍内环境温度略高于秋季,差异不显著（P＞0.05）;秋季舍内湿度显著高于冬季（P＜0.05）,两个季节的温湿度均可满足不同日龄肉鸡生长需求。有害气体和微生物检测结果显示,冬季舍内氨气浓度略高于秋季,差异不显著（P＞0.05）;冬季舍内二氧化碳浓度显著高于秋季（P＜0.05）;同时冬季舍内空气微生物总菌数显著高于秋季（P＜0.05）。层叠式立体笼养肉鸡舍内温度在不同季节可保持恒定;在冬季饲养期,舍内湿度降低,二氧化碳浓度升高,空气微生物总菌数升高。因此,冬季饲养肉鸡在做好保温的同时应适当增加通风换气。 相似文献
17.
The study was conducted to detect the indoor environmental quality parameters of broiler house with three-overlap cages and analyze the differences in winter and autumn. In the process of feeding, the same farming house in the same farm was chosen to carry out the test. The indoor ambient temperature, humidity and the air quality were determined in chicken house in different seasons. The measure points were distributed in 4 different positions in the house. The experiment period was from 3 to 6 weeks of broilers.The results showed that there was no significant difference in the ambient temperature between autumn and winter during experimental period (P >0.05). The ambient temperature in the house in winter was slightly higher than in autumn. The humidity in autumn was significantly higher than that in winter (P <0.05).The temperature and humidity in two seasons could meet the requirements of broiler growth. There was no significant difference in ammonia concentration between autumn and winter, while ammonia level in winter was slightly higher than that in autumn. The carbon dioxide in the house was significantly higher in winter than that in autumn (P <0.05). The total number of airborne bacteria in winter was significantly higher than that in autumn (P <0.05). The indoor temperature kept constant in autumn and winter seasons in closed poultry house. In winter, the humidity was reduced, the carbon dioxide concentration was increased, and the total number of bacteria in the air was increased.So, the ventilation should increase at the same time of heating in winter. 相似文献
18.
Airborne gram-negative bacterial flora in animal houses 总被引：1，自引：0，他引：1
Zucker BA Trojan S Müller W 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2000,47(1):37-46
The concentration and the species composition of airborne gram-negative bacteria were studied in four cattle houses, one pig house and one poultry barn. On average only between 0.02 and 5.2% of the total number of culturable aerobic bacteria were identified as gram-negative bacteria. Obligate anaerobic gram-negative bacteria were not isolated at all. In the airborne gram-negative bacterial flora the following bacterial families dominated: the Enterobacteriaceae, the Pseudomonadaceae and the Neisseriaceae. Within the family of the Enterobacteriaceae the species Escherichia coli and Enterobacter agglomerans were predominant. In animal houses using straw as bedding material Ent. agglomerans was most frequent, whereas in animal houses without litter E. coli was mainly found. Airborne Neisseriaceae were isolated very frequently in cow barns with Acinetobacter lowffii as the primary species. Airborne Pseudomonadaceae were found in high concentrations during periods of high air humidity. The results presented may also give some indications on the origin and sources of airborne endotoxins in animal housing. 相似文献
19.
Three air contaminants that may have serious health consequences to humans and poultry are ammonia, dust, and aerosolized bacteria. This study measured ammonia concentrations, dust concentrations, and the presence or absence of aerosolized Salmonella spp. and Escherichia coli inside and outside five commercial layer facilities. The average outside ammonia concentration measurements decreased as the distance from the facility increased from 10 to 40 ft. The measurements at 10 ft from the facilities were consistently higher than the average concentrations inside the facilities. The ammonia measurement trends inside of the facilities were affected by the temperature-dependent ventilation systems. Average dust concentrations inside the five facilities were consistently below 2 mg/m3. Three facilities also experienced average outside dust concentrations at all measured distances below 2 mg/m3. Two facilities had relatively high average dust measurements at 10 ft from ventilation fans (32.12 mg/m3 and 75.18 mg/m3). Escherichia coli and Salmonella were isolated from the air inside all five facilities and outside the facilities up to 40 ft from the ventilation fans. In condusion, dust concentrations may pose the largest risk to human and animal health at 10 ft away from the poultry facilities; risks associated with ammonia inhalation are greatest inside facilities during the coolest months of the year; and aerosolized bacteria are found inside and outside poultry facilities, but further work is needed to quantify the bacteria to further assess the health risk related to this issue. 相似文献
20.
Air hygiene in a broiler house: comparison of deep litter with raised netting floors 总被引：2，自引：0，他引：2
1. Deep litter and raised netting flooring systems in broiler houses were compared for their effects on air quality and bird health during an 8-week growing period. 2. Weekly measurements were taken of respirable dust, numbers of airborne microorganisms and concentrations of gaseous pollutants. Airborne fungi and bacteria were identified to species. 3. At the end of the experimental period, randomly sampled bird lungs were examined for the presence of viable microorganisms and for pathological changes. Bird health and performance were monitored throughout the 8 weeks. 4. Respirable dust concentrations and numbers of airborne microorganisms were significantly higher in the litter rooms. The type of floor had no effect on concentrations of gaseous ammonia. 5. Floor type had no significant effect on bird mortality but birds on litter had a slightly better gain:food ratio. However, birds on litter were observed to have a higher incidence of lung damage and more of the birds on litter had viable microorganisms present in the lungs at necropsy. 相似文献