[Composting of poultry carcasses as an alternative method for disposal in case of an outbreak of an epizootic disease: first results]. / Kompostierung von Geflügeltierkörpern als alternative Beseitigungsmöglichkeit im Tierseuchenkrisenfall: erste Ergebnisse.

Composting of poultry carcasses represents an alternative method for disposal in case of an outbreak of an epizootic disease. Two composting experiments, each with a different construction of the compost pile, were carried out in a stable. In the first experiment two layers of turkey carcasses were formed. This compost pile covered with straw was directly built on the ground. In the second experiment no layers of carcasses were formed, and it was assembled on straw bales covered with plastic foil. One part of this compost pile was covered with straw, the other one was additionally covered with plastic foil. In the first experiment in the upper layers of the compost pile temperatures of up to 54.9 degrees C were reached and the decomposition of carcasses was very advanced with no soft tissues remaining after 30 days. In contrast temperatures of only 45.2 degrees C were reached in the lower layers and decomposition was far less advanced. This difference in decomposition was most likely caused by the temperature difference observed. In the second experiment the near complete decomposition seen in the upper layers of the compost pile at the first trial, was not achieved. Decomposition was more advanced in the straw covered part of this compost pile than in the part covered with straw and plastic foil. On the other hand, higher temperatures of up to 48.4 degrees C were measured in the lower layers of this compost pile most likely as a result of the increased heat insulation in particular to the ground.

Identification of risk factors for sub-optimal housing conditions in Australian piggeries: Part 1. Study justification and design.

We undertook a literature search related to pig production facilities with two major aims: first, to review all the likely benefits that might be gained from air quality improvements; and second, to review previous research that had identified statistically significant factors affecting airborne pollutants and environmental parameters, so that these factors could be considered in a multifactorial analysis aimed at explaining variations in air pollutant concentrations. Ammonia, carbon dioxide, viable bacteria, endotoxins, and inhalable and respirable particles were identified as major airborne pollutants in the review. We found that high concentrations of airborne pollutants in livestock buildings could increase occupational health and safety risks, compromise the health, welfare, and production efficiency of animals, and affect the environment. Therefore, improving air quality could reduce environmental damage and improve animal and worker health. To achieve a reduction in pollutant concentrations, a better understanding of the factors influencing airborne pollutant concentrations in piggery buildings is required. Most of the work done previously has used simple correlation matrices to identify relationships between key factors and pollutant concentrations, without taking into consideration multifactorial effects simultaneously in a model. However, our review of this prior knowledge was the first important step toward developing a more inclusive statistical model. This review identified a number of candidate risk factors, which we then took into consideration during the development of multifactorial statistical models. We used a general linear model (GLM) to model measured internal concentrations, emissions, and environmental parameters in order to predict and potentially control the building environment.

Identification of risk factors for sub-optimal housing conditions in Australian piggeries: Part 2. Airborne pollutants.

The concentrations of total airborne bacteria, respirable endotoxins, ammonia, and respirable and inhalable particles were monitored in 160 piggery buildings in Australia between autumn 1997 and autumn 1999. The overall mean airborne bacteria, respirable endotoxins, ammonia (NH3), and inhalable and respirable particle concentrations measured were 1.17 x 10(5) cfu m(-3), 33.1 EU m(-3), 3.7 ppm, 1.74 mg m(-3), and 0.26 mg m(-3), respectively. The characteristics of the buildings and management systems used were documented at the time of sampling. A multifactorial general linear model (GLM) statistical procedure was used to analyze the effects of housing and management factors on the concentrations of the airborne pollutants. Both airborne bacteria and respirable endotoxin concentrations were affected by building classification (type), and respirable endotoxin concentrations were positively correlated with increasing humidity. The concentrations of airborne bacteria increased as the level of pen hygiene (cleanliness) decreased. The NH3 concentrations were primarily affected by level of pen hygiene, building volume, pig flow management, and season. Building classification, pig flow management, season, building volume, ventilation rates, and temperature affected inhalable particle concentrations. Respirable particle concentrations were primarily affected by building classification, pen hygiene, pig flow management, season, ventilation rates, temperature, and humidity. These findings suggest that environmental improvement strategies (such as improved cleaning, ventilation, and temperature control) are likely to reduce airborne pollutant concentrations in pig buildings and in the environment, thus improving the health and welfare of both pigs and farm staff.

Identification of risk factors for sub-optimal housing conditions in Australian piggeries: Part 3. Environmental parameters.

Between autumn 1997 and autumn 1999, we measured ventilation rates (using a CO2 balance method), air temperatures, and relative humidity (using self-contained dataloggers with built-in sensors) in 160 pig housing facilities in Queensland, South Australia, Victoria, and Western Australia, in each case over a 60 h period. In some buildings, the internal air velocities above the animals were also recorded. While the monitoring instruments were being set up, a detailed questionnaire was used to collect data on major housing features and management factors. This information was statistically analyzed to quantify the effects of housing and management factors on the resulting environment conditions using a multifactorial analysis. The overall mean air temperature, relative humidity, internal air velocity, and ventilation rate were 20.3 degrees C, 58.9%, 0.12 m s(-1), and 663.9 m3 h(-1) 500 kg(-1) live weight, respectively, across all buildings. Internal building temperature and humidity were affected statistically by the type of insulation material used, the classification of buildings, and external climatic conditions. Ventilation rates were primarily affected by the type of ventilation system used, height (size) of ventilation openings, stocking density (kg m(-3)), and length, width, and height of buildings. These findings should aid the development of strategies for the industry to improve environmental control in piggery buildings.

Suitability of biocompost as a bedding material for stabled horses: respiratory hygiene and management practicalities.

REASONS FOR PERFORMING STUDY: Bedding material in stables has an important influence on air hygiene and information on the suitability of biocompost and wood shavings is incomplete. OBJECTIVES: To compare the suitability and benefit of biocompost and wood shavings as bedding in horse stables and to determine key air factors for the evaluation of the potential impact of these materials on respiratory health. METHODS: The study was conducted in a naturally ventilated stable with 4 horses. Air hygiene parameters were measured 24 h/day for 7 days with each bedding type: ammonia (NH3), inhalable and respirable dust, endotoxins, colony forming units (CFU) of total mesophilic bacteria, fungi, actinomycetes and thermophilic actinomycetes. Both bedding materials were analysed for general chemical composition, particle size distribution and natural microbial content. The animals' behaviour was monitored by video cameras, and their health and cleanliness status determined by clinical and visual examination. RESULTS: Concentrations of NH3, dust, endoxins and fungi were significantly higher during the monitoring period with wood shavings than with biocompost. In contrast concentrations of mesophilic bacteria, mesophilic actinomycetes and thermophilic actinomycetes microbial pollutants were highest with biocompost. The water content of bulk biocompost was considerably higher than that of wood shavings. Particles < or = 0.4 mm were not detectable in bulk wood shavings. The concentration of thermophilic actinomycetes by weight in raw biocompost was 639 times higher than in raw wood shavings. No significant differences were observed in the time spent by the horses lying down. The biocompost material tended to adhere more intensively to the animals' hair coat. Horses showed no clinical signs indicating any adverse effects of the biocompost material during the trials. CONCLUSIONS: Biocompost cannot be recommended as bedding material for horses in stables, because the concentration of thermophilic actinomycetes and other agents that elicit and maintain recurrent airway obstructions was significantly higher with biocompost than with wood shavings. To ensure the well-being of horses, any new bedding material must be tested very carefully before it is introduced to the market.

[Total count of bacteria in the air of three different laying hen housing systems]. / Zum Umfang des allgemeinen Luftkeimgehaltes in drei verschiedenen Legehennenhaltungssystemen.

Bacteria in the air of animal housing is assumed to have an impact on the health of the humans and the animals in them and on the environment. The bacterial count in poultry housing systems is particularly high in comparison to those of pigs and cattle. Little is known about the bacteria in the air of new laying hen housing systems. We therefore made simple, simultaneous measurements in the air of three different systems (enriched cages, AK; conventional battery cages, BK; aviary, VOL), in the unheated scratching area of the VOL, and in the outside air over a period of one year (24-h samples were taken about once a month using polycarbonate filters) in order to determine the general bacterial count (using blood agar). The highest concentrations of bacteria were found all year long in the VOL, followed by the BK and the AK. In the VOL, there were on average 2.16 and 0.56 x 10(6) colony forming units (cfu)/m3 in the winter and summer, respectively; 0.25 and 0.38 in the BK; and 0.39 and 0.12 in the AK. These preliminary results show that air quality considerations should be included in the development and implementation of new housing systems, as should the impact on the respiratory system of the humans and animals in them and on the environment, because high concentrations of air contamination in the housing generally also lead to high emissions into the vicinity of the facility, the significance of which cannot always be estimated, as has recently been shown for antibiotics in the exhaust air from animal housing.

[A proposal for calculating the dustlike particle emissions from livestock buildings]. / Ein Vorschlag für die Berechnung staubförmiger Partikelemissionen aus Ställen der Nutztierhaltung.

Particles emitted from livestock buildings are supposed to cause health implications in nearby residents. This increasingly causes conflicts between farmers and neighbours. At the same time the national emission control regulations are tightened and focus also on the environmental impact of particulate emissions. In front of this background a calculation model is presented by which the emitted masses of PM10 and PM2.5 from animal houses can be estimated. The model may help to establish emission inventories for particulates in rural areas with livestock production and can become a valuable instrument of the emission control act. The validity of the proposed model depends largely on the quality and amount of the input data. The more valid data are available the more precise the model can work. Therefore it will be necessary to improve the data sets on emission amounts for PM10 and PM2.5. In spite of these limitations it appears that a first and reliable estimation of particulate emission amounts from animal buildings can be given by the proposed model calculation.

[Reduction efficiencies of a biofilter and a bio-scrubber as bio-aerosols in two piggeries]. / Untersuchungen zum Rückhaltevermögen eines Biofilters und eines Biowäschers für Bioaerosole an zwei Schweineställen.

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.

[Orienting endotoxin measurement in the atmosphere]. / Orientierende Endotoxinmessungen in der Aussenluft.

Airborne endotoxins are supposed to influence the respiratory health of animal and man in animal housings as well as at certain work places in agriculture. Little is known about the usual concentrations of endotoxin in the outdoor atmosphere. Therefore in a field study 30 air samples were taken, 22 samples in a rural region, and 8 in a more residential and industrial area. The samples were taken by impingement and filtration. The analysis was carried out by means of the chromogen-kinetic limulus amoebocyte lysate test (LAL-Test). The median concentration of all samples was 0.36 ng/m3. The highest median concentration of 0.49 ng/m3 was found in summer with a maximum value of 1.80 ng/m3 indicating large variations. In the other seasons the median concentrations (ng/m3) were distinctly lower (spring: 0.30, n = 11; autumn: 0.26, n = 5; winter: 0.19, n = 3). No significant differences were observed between farming and residential areas at this low concentration level. The concentrations of endotoxin found in this study were far below all threshold limits which are presently discussed for work places.

[Emission of particulates from a pig farm with central air exhaust in the pig stall]. / Freisetzung partikelförmiger Stoffe aus einem Schweinestall mit zentraler Abluftführung in die Stallumgebung.

There is increasing concern that airborne dust and particulates from animal enterprises which are emitted into the environment may impair the health of people living in nearby residential areas. Investigations were carried out to trace the distribution of particulate emissions from a piggery in the vicinity by means of an aerosol lidar. Additionally, dust was sampled with a high volume impactor (HVS) at two places downwind (50 m, 115 m) and at a reference point 50 m upwind the piggery. The total dust concentraction in the animal house air varied between 0.2 and 1.0 mg/m3 within 24 hours. 50 m downwind the building 0.08 mg/m3 dust was measured by means of the HVS. At a distance of 115 m downwind the same concentrations (0.037 mg/m3) as the reference point (0.037 mg/m3 upwind the animal house were found. The endotoxin concentrations were 60 ng/m3 (50 m downwind), 15 ng/m3 (115 m downwind) and 9 ng/m3 (50 m upwind). The lidar signals discriminated clearly between the density of the air directly above the exhaust chimney and the 115 m downwind position. It seems that the lidar technique in combination with high volume impaction form an useful tool to describe the distribution distance of particulate pollutants farm animal housing.

[Emissions and immisions of bio-aerosols from a duck fattening unit]. / Emissionen und Immissionen von Bioaerosolen aus einem Entenmaststall.

In a field study emissions and immissions (receptor exposition) of bioaerosols emitted from and near a duck fattening house (25 m distance) were investigated. Within the livestock building mean concentrations of 3,342,289 CFU m-3 for airborne total mesophilic bacteria were determined. Total dust and endotoxin yields were 1.9 mg m-3 and 7,132.4 ng m-3, respectively. Additionally, enterobacteria, mesophilic and thermotolerante fungi as well as mesophilic actinomycetes were detectable. Measurements of immissions have shown, that downwind in the rear of the house a mean total germ concentration of 10,007 CFU m-3 was measurable in contrast to the upwind side of the building, where no airborne mesophilic bacteria were found. Higher concentrations downwind were generally determined for total dust, mesophilic fungi and actinomycetes, too, but not so for endotoxins. A supporting application of a numeric dispersion model confirmed the immissions for total mesophilic bacteria near by the duck fattening house. From this viewpoint immission predictions can be made in future for varying input data, i.e. wind conditions, of different components of bioaerosols.