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1. The objective of this study was to determine the level and variation of the total mass, and load of nitrogen (N) and phosphorus (P) excreted into the outdoor run of organic egg production systems. 2. Three egg production farms with an aviary system and an outdoor run were selected for this study. Four measurements, one per season, were executed on each farm. 3. Mean content of N and P of a manure dropping was 14·0¿g N¿kg-1 and 3·12¿g P¿kg-1, mean mass of a dropping was 6·36¿g and mean dry matter content of a dropping was 238¿g¿kg-1. Mean rate of excretion in the outdoor run was 2·99 droppings per hen per h. Mean percentage of hens outside during the time the outdoor run could be accessed was lowest on Farm 1 (1·7%), highest on Farm 2 (16·0%), and intermediate on Farm 3 (7·1%). 4. On all farms an exponential decrease of the number of hens and of the load of N and P with increasing distance from the hen house was found. Load of N exceeded the fertilisation standard (of 170¿kg¿ha-1¿y-1) in the region at a 0 to 19¿m distance from the hen house on Farm 1, 0 to 146¿m on Farm 2 and 0 to 52¿m on Farm 3. 5. It is concluded that the husbandry system should be redesigned to solve the problem of overloading, unwanted loss of N and P to the environment and loss of N and P from the organic production cycle.

By sampling aerosolized microorganisms, the efficiency of a bioaerosol sampler can be calculated depending on its ability both to collect microorganisms and to preserve their culturability during a sampling process. However, those culturability losses in the non-sampling processes should not be counted toward the sampling efficiency. Prior to the efficiency assessment, this study was designed to investigate the culturability losses in three non-sampling processes: (1) the tracer uranine induced loss; (2) the loss during aerosolization (pre-sampling process); and (3) the bacteria and uranine recovery in air sample handling procedures for the samples of the Andersen 6-stage impactor and the Airport MD8 (post-sampling process). The results indicated that uranine had no significant effect on the culturability of Enterococcus faecalis, Escherichia coli, and Mycoplasma synoviae in suspensions (P > 0.05), but negatively affected the culturability of Campylobacter jejuni (P = 0.01). The culturability of E. faecalis, E. coli, and M. synoviae was not affected by stresses caused by aerosolization (P > 0.05). Only 29% of C. jejuni were still culturable during aerosolization (P = 0.02). In the air sample handling procedures, the four species of bacteria were recovered without significant losses from the samples of the Andersen impactor, but only 33-60% uranine was recovered. E. faecalis, E. coli, and M. synoviae were recovered without significant losses from the samples of the Airport MD8. More C. jejuni was recovered (172%), probably due to multiplication or counting variation. It is suggested that tracer and bacteria should be aerosolized separately when the tracer negatively affects the bacterial culturability. In both pre- and post-sampling processes, losses of bacterial culturability (or multiplication) may occur, which should be taken into account when assessing the efficiencies of bioaerosol samplers.

The analyses of the different sources which can contribute to particulate matter (PM) emissions from livestock houses are essential to develop adequate reduction techniques. The aim of this study was to morphologically and chemically characterize several sources of PM from livestock houses. We collected known sources of PM from different housing systems for poultry and pigs, which were later aerosolized in a customized laboratory dust generator to collect fine and coarse PM samples. These samples were morphologically and chemically characterized using scanning electron microscopy with X-ray microanalysis to develop comprehensive morphological and chemical source profiles. Moreover, source particle-size distribution was determined. Results showed distinct and unique particle morphologies in collected sources from different housing systems for poultry and pigs. Although presence of N, Na, Mg, Al, Si, P, S, Cl, K, and Ca were identified in all sources, their relative element concentrations varied amongst sources and could be used to discriminate amongst them. Particle size and size distribution also varied amongst sources (size ranged from 2.1 ¿m to 18.1 ¿m projected area diameter), and mainly depended on its mineral or organic origin. The results from this work can be useful information for source identification and quantification in PM from livestock houses, improving the understanding of how PM is generated in such environments, and developing strategies for its reduction. © 2010 Elsevier Ltd., We acknowledge the support of the Dutch Ministry of Agriculture, Food Quality and Nature that financed this study. We thank the Servicio de Microscopia Electronica (Universidad Politecnica de Valencia) for expert technical assistance during SEM analysis. The help from T. Hermosilla (Geo-Environmental Cartography and Remote Sensing Research Group, Universidad Politecnica de Valencia) in image analysis and M. Montero in the dust generation of samples is also acknowledged.

Livestock housing is an important source of emissions of particulate matter (PM). High concentrations of PM can threaten the environment, as well as the health and welfare of humans and animals. Particulate matter in livestock houses is mainly coarse, primary in origin, and organic; it can adsorb and contain gases, odorous compounds, and micro-organisms, which can enhance its biological effect. Levels of PM in livestock houses are high, influenced by kind of housing and feeding, animal type, and environmental factors. Improved knowledge on particle morphology, primarily size, composition, levels, and the factors influencing these can be useful to identify and quantify sources of PM more accurately, to evaluate their effects, and to propose adequate abatement strategies in livestock houses. This paper reviews the state-of-the-art of PM in and from livestock production systems. Future research to characterize and control PM in livestock houses is discussed. Control of particulate matter emissions, a major challenge to modern livestock production.

Pathogen-associated molecular patterns (PAMP) such as lipopolysaccharide (LPS), lipoteichoic acid, beta-glucans (BGL), and possibly many others are important parts of (fine) dust in animal houses. When intratracheally (i.t.) administered, PAMP affected specific primary and secondary humoral immune responses to concurrently i.t. or systemically administered antigens and BW gain (BWG) of layer chickens. In the present study, we evaluated the effects of i.t. challenge with various PAMP known to be present in dust: LPS, lipoteichoic acid, zymosan-A (containing 1,3 BGL), next to heat-inactivated dust particles as a representative of mechanical stress, a combination of the former components, and NH3 as a chemical component of dust on primary and secondary (total) systemic antibody (Ab) responses and (isotype) IgM and IgG responses to concurrently i.t.-administered human serum albumin (HuSA) in broilers. Birds were challenged via the trachea for 2 consecutive days at 3 and 7 wk of age, respectively. All treatments affected immune responses at several moments, BWG, and heart morphology. beta-Glucans and LPS affected the birds most pronounced and for a prolonged period. Intratracheally administered LPS and BGL significantly enhanced primary and secondary total Ab, IgM Ab, and IgG Ab responses to HuSA. All birds that were challenged with dust, PAMP, or NH3 concurrently with HuSA showed a decreased BWG especially after primary, but also after secondary challenge. Weight, width, and length of hearts were enhanced in dust and PAMP-treated birds as well when these birds were challenged with HuSA. The present results indicated that components of dust such as PAMP when i.t. administered affect humoral immune responsiveness of broilers, which may lead to an enhanced status of immune reactivity. Furthermore, our results suggest that the hygienic status of the environment influences BWG and may affect heart morphology, and as a consequence physiology in broilers. The consequences of our findings with respect to dust, (airborne) PAMP, hygienic conditions in the barn, and immune responsiveness of broilers are discussed.

The objective of this study was to determine the effects of dietary crude protein (CP) level on odour emission, odour intensity, odour hedonic tone, ammonia and greenhouse gaseous emission from pig manure, and on fresh faeces and manure characteristics. An experiment was conducted with finishing pigs (n = 12) in a randomized complete block arrangement with 2 treatments of 12 and 15% dietary CP in six blocks. The 2 diets were supplemented with essential AA up to the level of the animal's requirement. Pigs with an initial body weight (BW) of 57.7 ± 0.7 kg were penned individually in partly slatted floor pens. Faeces and urine of each pig accumulated in separate manure pits under the slatted floor. In the 3rd week of the collection period, fresh faeces were collected for identifying fresh faeces characteristics and for assessing dry matter, organic matter, nitrogen (N), fat and non-starch polysaccharides digestibility using Cr2O3 as a marker. In the 6th week of the collection period, air samples were collected directly from each manure pit: one for odour, one for ammonia concentration and one for greenhouse gases. Afterwards the manure was mixed and a representative sample was taken for manure characteristic analysis. Odour samples were analyzed for odour concentration and for hedonic tone and odour intensity. Manure samples were analyzed for volatile fatty acids (VFA), indolic, phenolic, sulphurous compounds, ammonium and total N concentrations and pH. Reducing dietary CP level from 15 to 12% did not affect odour emission, odour intensity and odour hedonic tone and greenhouse gaseous concentration (CH4, CO2 and N2O) (P > 0.05) of odorous air above the manure pit. Reduced dietary CP level decreased manure pH (P

The behaviour and physiology of intensively housed animals will be negatively affected when the environmental temperature is above their thermo-neutral zone (TNZ). It is likely that production efficiency, welfare, health and reproductive capacity of the animals will be compromised. Traditional technologies, such as the use of different cooling systems and better building design, can be used to alleviate the negative effects of high temperatures on animals. However, there are real opportunities to further develop climate control technologies and create intelligent environmental control systems that will be able to predict and therefore control both the responses of animals and the buildings in relation to selected control interventions.

An experiment was conducted in growing pigs to determine the effects of content of potentially fermentable protein (FP) on odour and ammonia emissions from pig manure and on manure characteristics. Pigs (n = 18) were allocated in a randomised complete block arrangement with 3 treatments in each of 6 blocks. The three treatments had 28.4, 38.2 and 48.0 g fermentable protein per kg of feed. Pigs with an initial body weight (BW) of 41.3 ± 3.2 kg (mean ± S.D.) were housed individually in pens with partly slatted floor and offered a daily feed allowance of 2.8 × maintenance requirement (293 kJ net energy (NE)/BW0.75). Feed was mixed with water (1/2.5; w/w). After a 2-week adaptation period faeces and urine produced by each pig were collected in individual manure pits under the slatted floor. In the 5th week of the collection period air samples were collected from each manure pit for odour and ammonia analyses. Odour characteristics were measured by olfactometry and ammonia was measured by using two ammonia traps each containing 20 ml 0.5 M HNO3 solution. Manure samples from each manure pit, taken in the same week as air samples, were analysed for volatile fatty acids (VFAs), indolic, phenolic, sulphurous compounds, ammonium nitrogen and total nitrogen concentrations. Data were evaluated using analysis of variance. Odour and ammonia emissions from pig manure were in the range from 1.88 to 2.78 ouE/(s m2) and from 0.011 to 0.014 mg/(s m2), respectively and were not affected by fermentable protein content of the diet (P > 0.05). Increased fermentable protein content resulted in higher concentrations of total nitrogen, methyl sulphide, carbon disulphide, ethanethiol, phenol, 3-methyl indole and 4-ethyl phenol in the manure (P 0.01), but did not influence ammonium nitrogen, volatile fatty acids, cresols and indole concentrations in the manure. It is concluded that a decrease in the fermentable protein content of the diet does not reduce odour emission, odour intensity (OI) or odour hedonic tone (HT) in pigs.

The aim of this study was to determine the level and variations in ammonia emissions from buildings and outside yards, with different manure removal systems, for organically raised fattening pigs. Ammonia emissions were determined at three farms with organically raised pigs. Amongst other differences, farms mainly differed in manure removal system at the outside yard. Measurements were carried out during two measuring seasons, with two categories of pigs: fatteners of 45 and 80 kg. Excreting behaviour was analysed by video observations and ammonia emission was measured by the ventilated chamber technique. There were clear differences in ammonia emission between farms (probability, P

The effects of relative humidity and ambient temperature on evaporative heat loss were studied in 12 trials each with a group of 10 gilts with an initial BW of 61.7 kg (58.0–65.5 kg). The ambient temperature inside a respiration chamber was increased by 2 °C d −1 starting at 16 °C and ending at 32 °C. Relative humidity was set at 50%, 65% or 80% and remained constant within each trial. The animals had free access to feed and water. Skin temperature (SkinT), total heat production (HP), evaporative heat loss (EvapH), respiration rate (RR), and wallowing of the animals were recorded. SkinT was lowest at 80% relative humidity ( P P −1 d −1 and EvapH increased by 290 kJ pig −1 d −1 ( P

In different parts of Europe animal production is highly concentrated. Pig production generally is the main animal production activity in these areas. Main concerns of these large numbers of pigs are the amount of surplus nutrients in excreta and gaseous losses to the environment. Main nutrients of concern are N, P, and heavy metals and main gaseous losses of concern are ammonia, odour, and methane. Although losses are inevitable to a certain extent, nutrition seems to be a key factor in reducing these losses. Main nutritional strategies to reduce N and P excretions from pigs are: phase feeding (N, P), supplementation of limiting amino acids to the diet (N), and addition of phytase to the diet (P). Nutritional strategies to reduce heavy metals excretions from pigs are: finding alternative, natural, growth promoters that could replace Cu and Zn in the diet; using feedstuffs for the diet that are less contaminated with Cd. Main strategies to reduce ammonia emissions are: 1) lowering crude protein intake in combination with addition of limiting amino acids; 2) Shifting nitrogen excretion from urine to faeces by including fermentable carbohydrates in the diet; 3) lowering pH of urine by adding acidifying salts to the diet; 4) lowering the pH of faeces by inclusion of fermentable carbohydrates in the diet. These strategies proved to be independent from each other and effects are additive. By combining these strategies a total reduction of ammonia emission in growing-finishing pigs of 70% could be reached. Strategies to reduce odour emission are: 1) reducing protein fermentation by balancing available protein and fermentable carbohydrates in the large intestine; 2) Minimizing breakdown of absorbed sulphur amino acids. More studies are needed in this area of research, but results until now are very promising. A clear relationship exists between fermentable carbohydrates in the diet and methane emissions. This disadvantage should be considered when tackling ammonia emission by this strategy. It is concluded that there is a large potential to reduce environmental load within pig dense areas by nutritional means.

A model was developed as a tool for designing straw-bedded sow group-housing systems with low ammonia emission. Using mechanistic and empirical relationships it calculates the total ammonia emission by integrating ammonia volatilisations from all the urine pools in the house. The reference data were from a house with a floor comprising 60% straw bedding, 14% drinking area (slatted floor with pit), 3% waiting area (slatted floor with pit) and 23% alley (solid floor). Simulations were performed to elucidate the effect of the distribution of the urinations over the different surfaces, relating this to the size and distribution of the urine pools, and the area of the surfaces urinated upon. The results were compared with emission data from an entire sow house. When the default settings were a urine production of 7 l/d per sow, a urination frequency of 5 times a day per sow, and urinations distributed evenly over the four emitting surfaces the model estimated the ammonia emission from the entire house as 11.7 g/d per sow, and the relative contributions of the straw bed, the drinking area, the waiting area and the alley as, respectively, 27%, 22%, 9% and 42%. By comparison, the actual emission from the house was 8.7 g/d per sow. The 90% confidence interval was 6.5¿10.9 g/d per sow. Increasing the size of the urine pool from 0.14 m2 to 1.40 m2 in the model simulations caused ammonia emission initially to increase from 9.7 to 12.1 g/d per sow when the pool volume was 0.47 m2. If the pool was bigger, emission fell to 10.6 g/d per sow because, though the larger emitting area increases ammonia emission, the increase is outweighed by the reduction in emission caused by successive, superseding urinations on the same spot. If the entire emitting area was assumed to be straw bedding, the calculated emission from the house was 5.8 g/d per sow. Assuming slatted and concrete floors without straw bedding increased the emission to 16.5 g/d per sow. It is concluded that measures to reduce the ammonia emission from the bedded sow house should be aimed at decreasing the emission from the solid floor and/or allowing more urinations on the straw bed. The model is a useful design tool for achieving emission reduction from group-housing systems for sows with straw bedding. Its predictive power would be improved by inputting data on the actual size of the urine pool and urinating behaviour of sows.

The main objective of this study was to quantify ammonia emissions from organically raised pregnant sows and to compare them with emissions from conventional pig production. A second objective was to quantify the nutrients deposited in the paddock in organic pig grazing systems. Measurements were carried out on three Dutch farms on 1 day in each of two measuring seasons (spring/summer and autumn). Ammonia emissions were measured by the ventilated chamber technique at different locations inside the building and on the paved outside yard. The nutrient loads of N, P and K were calculated according to their content in urine and faeces, average weight of urine and faeces per excretion, and number of urinations and defecations in the paddock. Ammonia emission per m2 did not differ statistically significantly between seasons and between inside and outside the building. Fouling of the floor with urine and faeces had a strong effect on ammonia emission (probability P 0 · 0 0 1 ). Emissions varied greatly between farms. When emissions were calculated per kg per pig place per year, on one farm they far exceeded the Dutch standard for regular pig farming. On the other two farms they slightly exceeded the standard. The main reason seems to be that pregnant sows on organic farms have outside yards, which are an additional source of ammonia emission. The nitrogen and phosphorus loads on the paddock varied greatly between the farms, statistically significant for N ( P 0 · 0 1 ) , not significant for P and significant for K ( P 0 · 0 5 ) . The total amount of nutrients on one of the farms (407·5 kg ha−1 yr−1 for N and 113 kg ha−1 yr−1 for P) far exceeded the permitted levels (170 kg ha−1 yr−1 for N and 44 kg ha−1 yr−1 for P).

We report a study on crossbred growing pig ((Duroc x Pietrain) x Large White) that measured the effect of tropical conditions on respiration rate (RR), skin temperature (ST), rectal temperature (RT) and productivity and determined the efficacy of two simple cooling methods. The experiment was a randomized complete block design using 120 growing pigs. The factors were cooling system and pen design. The effects of two cooling systems (water bath (WB) and sprinkling (S)) were evaluated and compared with a control (CON). Cooling systems were tested in pens with (Y) or without an additional outdoor yard (NY). The pens were similar to those used in small-scale pig keeping in South-East Asia. The inside pen size was 2.5 x 3 m, the yard was 2.5 x 2 m. The same experimental design was used in two blocks: one block was in the wet season with average ambient temperature (T) of 27.5 degrees C and average relative humidity (RH) of 74.7% and the other was in the dry season with average T of 28.7 degrees C and average PH of 62.8%. In each block a batch of 60 pigs was reared in 12 pens (five pigs per pen). Pigs had free access to feed and water. Results showed that cooling and pen type significantly affected most parameters. The bath and S reduced RR by 4.2 and 5.2 min(-1), respectively (P

De Star+-stal is ruim twee jaar geleden in gebruik genomen op het Varkens Innovatie Centrum in Sterksel. In dit artikel wordt ingegaan op de achtergronden van deze stal en welke onderzoeken er de afgelopen twee jaar zijn gedaan. De resultaten van deze onderzoeken zullen in meer detail in andere artikelen worden beschreven.

De Star+-stal is ruim twee jaar geleden in gebruik genomen op het Varkens Innovatie Centrum in Sterksel. In dit artikel wordt ingegaan op de achtergronden van deze stal en welke onderzoeken er de afgelopen twee jaar zijn gedaan. De resultaten van deze onderzoeken zullen in meer detail in andere artikelen worden beschreven.

Large amounts of airborne microorganisms are emitted from livestock production. These emitted microorganisms may associate with dust, and are suspected to pose a risk of airborne infection to humans in vicinity and to animals on other farms. However, the extent to which airborne transmission may play a role in the epidemic, and how dust acts as a carrier of microorganisms in the transmission processes is unknown. This paper presents the current knowledge of the entire process of airborne transmission of microorganisms - from suspension, transportation until deposition and infection - and their relation to dust. The sampling and the mitigation techniques of airborne microorganisms and dust in livestock production systems are introduced as well.

The objective of this research was to assess the potential to reduce the integral ecological impact (i.e. impact along the egg production chain per kg egg) of Dutch organic egg production by replacing currently used imported diet ingredients with Dutch diet ingredients. We realized this objective by comparing the life cycle assessments (LCA) of current Dutch organic egg production, i.e. base situation (B) with different scenarios. In each scenario, one imported diet ingredient was replaced with a diet ingredient produced in the Netherlands. Finally, we formulated a scenario in which several ingredients, that individually resulted in the lowest mean change in ecological impact along the organic egg production chain, were replaced simultaneously. We included differences between production chains in cultivation (i.e. field operation, manure application and yield), transport, feed intake, egg production and N excretion. Replacement of Ukrainian wheat with Dutch triticale, and of Brazilian soybeans, Italian sunflower seed expeller and German peas with Dutch rapeseed expeller reduced the integral ecological impact compared with current organic egg production. Simultaneous replacement of these ingredients (scenario MU) resulted in an overall lower and more balanced reduction of the different ecological impacts (41–101%) than single replacement of these ingredients (41–215%). Compared with B ecological impact of scenario MU decreased for global warming potential (91%), energy use (79%), land occupation (68%), acidification potential (99%), N deficit (85%), P deficit (41%) and P surplus (81%), but slightly increased for N surplus (101%). The low ecological impact of MU was explained by (1) a relative small increase in feed conversion ratio (from 2.32 for B to 2.37 for MU), (2) a reduction of the transport distance of 44.4% of the diet ingredients, (3) replacement of the currently used crops with crops that have a higher yield in combination with a balanced applied amount of N and P in manure, and (4) use of expeller instead of whole ingredients.

In this desk study, twelve measures were evaluated for their ability to reduce greenhouse gas (GHG) emissions from pig and poultry houses. A number of measures show good perspective for GHG reduction in animal houses, but an integral analysis, including the complete manure chain and all relevant components, is needed to determine the true perspective of these measures. In deze deskstudie is het perspectief bepaald van een twaalftal potentiële maatregelen ter vermindering van broeikasgasemissies uit varkens- en pluimveestallen. Hoewel een aantal maatregelen perspectiefvol lijkt t.a.v. emissies uit stallen, is een integrale analyse van de gehele mestketen en alle milieucomponenten noodzakelijk om de werkelijke milieuwinst vast te stellen.

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The objective of this study was to determine the effects of dietary crude protein (CP) level on odour emission, odour intensity, hedonic tone, and ammonia emission from pig manure and on manure composition (pH, total nitrogen, ammonium, volatile fatty acids, indolic, phenolic and sulphur-containing compounds). An experiment was conducted with growing pigs (n = 18) in a randomised complete-block design with three treatments in six blocks. Treatment groups were 12%, 15% and 18% CP diets. Barley was exchanged for soya-bean meal. Crystalline amino acids (AA) were included in the 12% CP diet up to the level of pigs' requirement; the same amount of AA was added to the 15% and 18% CP diets. Pigs with an initial body weight (BW) of 36.5 ± 3.4 kg (mean ± s.d.) were individually penned in partly slatted floor pens and offered a daily feed allowance of 2.8 × maintenance requirement for net energy (NE: 293 kJ/kg BW0.75). Feed was mixed with water, 1/2.5 (w/w). Faeces and urine of each pig were accumulated together in a separate manure pit under the slatted floor. After an adaptation period of 2 weeks, the manure pits were cleaned and manure was collected. In the 5th week of the collection period, air samples for odour and ammonia analyses, and manure samples were collected directly from each manure pit. Air samples were analysed for odour concentration and for hedonic value and intensity above odour detection threshold. Manure samples were analysed for volatile fatty acids, and indolic, phenolic and sulphurous compounds, ammonium and total nitrogen concentrations. Reducing dietary CP from 18% to 12% lowered odour emission ( P

Survival of airborne virus influences the extent of disease transmission via air. How environmental factors affect viral survival is not fully understood. We investigated the survival of a vaccine strain of Gumboro virus which was aerosolized at three temperatures (10°C, 20°C, and 30°C) and two relative humidities (RHs) (40% and 70%). The response of viral survival to four metrics (temperature, RH, absolute humidity [AH], and evaporation potential [EP]) was examined. The results show a biphasic viral survival at 10°C and 20°C, i.e., a rapid initial inactivation in a short period (2.3 min) during and after aerosolization, followed by a slow secondary inactivation during a 20-min period after aerosolization. The initial decays of aerosolized virus at 10°C (1.68 to 3.03 ln % min −1 ) and 20°C (3.05 to 3.62 ln % min −1 ) were significantly lower than those at 30°C (5.67 to 5.96 ln % min −1 ). The secondary decays at 10°C (0.03 to 0.09 ln % min −1 ) tended to be higher than those at 20°C (−0.01 to 0.01 ln % min −1 ). The initial viral survival responded to temperature and RH and potentially to EP; the secondary viral survival responded to temperature and potentially to RH. In both phases, survival of the virus was not significantly affected by AH. These findings suggest that long-distance transmission of airborne virus is more likely to occur at 20°C than at 10°C or 30°C and that current Gumboro vaccination by wet aerosolization in poultry industry is not very effective due to the fast initial decay.

We studied the effects of a concurrent challenge on slow-growing broilers with 1) airborne particles of 2 sizes: fine dust (smaller than 2.5 microns) and coarse dust (between 2.5 and 10 microns) that were directly collected from a broiler house and 2) lipopolysaccharide on intratracheal immunizations with the specific antigen human serum albumin (HuSA) and measured primary and secondary systemic (total) antibody responses and (isotype-specific) IgM, IgG, and IgA responses at 3 and 7 wk of age. All treatments affected immune responses at several ages, heart morphology, and BW gain, albeit the latter only temporarily. Dust particles significantly decreased primary antibody (IgT and IgG) responses to HuSA at 3 wk of age but enhanced IgM responses to HuSA at 7 wk of age. Dust particles decreased secondary antibody responses to HuSA, albeit not significantly. All of the birds that were challenged with dust particles showed decreased BW gain after the primary but not after the secondary challenge. Relative heart weight was significantly decreased in birds challenged with coarse dust, fine dust, lipopolysaccharide, and HuSA at 3 wk of age, but not in birds challenged at 7 wk of age. Morphology (weight, width, and length) of hearts were also affected by the dust challenge at 3 wk of age. The present results indicate that airborne dust particles obtained from a broiler house when intratracheally administered at an early age affect specific humoral immune responsiveness and BW gain of broilers to simultaneously administered antigens differently than when administered at a later age. The hygienic status of broiler houses at a young age may be of importance for growth and immune responsiveness, and consequently, for vaccine efficacy and disease resistance in broilers. The consequences of our findings are discussed.

In the Netherlands, measures for mitigation of Particulate Matter (PM) emissions are needed for poultry houses to lower their contribution to elevated ambient PM concentrations. In this study, we 1) investigated whether on-farm drying systems (DS) for poultry manure can remove PM from the exhaust air flow, and 2) evaluated the contribution of DS to ammonia emissions. At two layer facilities, a total of twelve 24-hour measurements were carried out of temperature, relative humidity, ventilation rate, PM and ammonia between December 2009 and February 2010. A substantial removal of inhalable dust (69% for house 1), PM10 (83% for house 1; 33% for house 2) and PM2.5 (57% for house 1; 32% for house 2) was found. Concentrations of ammonia however, increased by a factor 5.0 (house 1) and 3.6 (house 2) over the manure layer. This study shows that DS for poultry manure show good ability to remove PM, but further research is necessary to avoid problem swapping by elevating emissions of other pollutants.

Further research is needed to validate real-time continuous devices for particulate matter (PM) against gravimetric samplers in livestock houses to obtain accurate absolute values. The objective of this study was to compare co-located real-time light scattering samplers and the equivalent gravimetric sampler in different poultry and pig livestock houses for PM10 mass concentration and to develop livestock-specific calibration factors for light scattering samplers. Paired DustTrak light scattering device (DustTrak aerosol monitor, TSI, U.S.) and PM10 gravimetric cyclone sampler (URG Corp., U.S.) were used for measuring PM10 mass concentrations during 24 h periods (from noon to noon) inside livestock houses. Sampling was conducted in 32 livestock houses in the Netherlands, including broilers, broiler breeders, layers in floor and in aviary system, turkeys, piglets, growing-finishing pigs in traditional and low emission housing with dry and liquid feed, and sows in individual and group housing. A total of 119 pairs of 24 h measurements (55 for poultry and 64 for pigs) were recorded and analyzed using linear regression analysis. In poultry, cyclone sampler and DustTrak data fitted well to a linear regression, with a regression coefficient equal to 0.41, an intercept of 0.16 mg/m3 and a correlation coefficient of 0.91 (excluding turkeys). In pigs, we found a regression coefficient equal to 0.61, an intercept of 0.05 mg/m3 and a correlation coefficient of 0.84. Measured PM10 concentrations using DustTraks were clearly underestimated (approx. by a factor 2) in poultry as in pigs compared with cyclone pre-separators. DustTrak light scattering devices should be self-calibrated to investigate PM10 mass concentrations accurately in livestock houses.

Het effect van huisvestings- en managementmaatregelen op de ammoniakemissie bij leghennen, vleeskuikens, kalkoenen en eenden is door Wageningen UR Livestock Research onderzocht.

The effects on the emissions from pig houses of a low protein diet with and without the partial replacement of calcium carbonate by calcium chloride were studied. De effecten op de emissies uit vleesvarkensstallen in de praktijk werden onderzocht van eiwitarm voer zonder en met gedeeltelijke vervanging van calciumcarbonaat door calciumchloride. Hiertoe werden op vier bedrijven emissiemetingen uitgevoerd. Het effect van een emissie-arme voervariant werd binnen elk bedrijf vergeleken met een gangbaar voer als controle.

This reports describes the results of a research on the effects of spraying water on bedding material on the fine dust, ammonia and odor emissions of laying hens in aviary housing systems. In dit rapport worden de resultaten beschreven van een onderzoek naar de effecten van het aanbrengen van een waterfilm op het strooisel op de fijnstof-, ammoniak- en geuremissie bij leghennen in volièresystemen.

In this study the options are shown to reduce ammonia emission from sow houses by feeding measures. In deze studie worden de mogelijkheden geïnventariseerd, inclusief effecten en kosten, om de ammoniakemissie uit zeugenstallen te reduceren via voermaatregelen.

The significance of airborne transmission in epidemics of infectious diseases in the livestock production industry remains unclear. Using infectious bursal disease virus (IBDV) as a viral model, this study investigated the shedding route (feces vs. exhaled air) of virus by broilers and the emission of airborne virus from an experimental room with 526 broilers which were orally inoculated at age 20 days. The airborne virus was sampled by three different bioaerosol samplers: Andersen six-stage impactor, all-glass impinger (AGI-30) and OMNI-3000. The results showed infected broilers started to shed virus in feces on day 5 post inoculation (PI), and stopped shedding on day 12 PI. The fecal virus remained detectable for at least two days after drying under broiler room conditions. No virus was detected in air exhaled by broilers. The airborne virus was detected on days 5, 8 and 12 PI at 20 cm above the floor, and on days 8 and 12 PI in exhausted air. The emission rates of IBDV were 4.0 log10 50% tissue culture infectious dose (TCID50) bird-1 day-1 on day 8 PI, and 4.5 log10 TCID50 bird-1 day-1 on day 12 PI.

This report describes potential measures on housing and management to reduce ammonia emission from laying hen, broiler, turkey and duck houses. In dit rapport zijn de mogelijkheden geïnventariseerd om de ammoniakemissie op leghennen-, vleeskuiken-, kalkoenen- en eendenbedrijven te verminderen door relatief eenvoudige maatregelen op het gebied van voeding, huisvesting en management of één of meerdere combinatie(s) van maatregelen.

To determine ventilation rates from mechanically ventilated livestock buildings fan-wheel anemometers have been extensively used. This method is reasonably accurate, but the cost of deploying this method is high, especially when a livestock building is provided with a large number of ventilation fans as may be the case in poultry livestock buildings. Here the CO2 mass balance method may provide a cost effective alternative. In this paper, the accuracy of this method for the determination of ventilation rates in mechanically ventilated livestock buildings in The Netherlands was evaluated with existing data from finished and on-going Dutch studies for pig and poultry categories. Fan-wheel anemometers were used as a reference method. The results from this analysis indicated that (under Dutch conditions) the CIGR method could be applied with reasonable accuracy to estimate the ventilation rate from livestock buildings for broilers, fattening pigs, sows and piglets. Using the CIGR method requires accurate registration of the parameters used in the model (animal weight, feed characteristics, and the production of meat/eggs from the animals) and accurate CO2 concentration measurements.

Emissions of dust, pathogens and gases have been measured in two goat houses. Coxiella burnetii, the bacteria responsible for Q-fever, could be detected in a number of dust samples. Het doel van dit onderzoek was om de emissies van stof en ziektekiemen uit representatieve geitenstallen vast te stellen (fase I) en vervolgens naar oplossingen te zoeken om de emissie en de verspreiding van C. burnetii uit stallen voor melkgeiten en melkschapen te voorkomen (fase II). Het onderzoek is uitgevoerd in twee moderne representatieve stallen voor melkgeiten op twee verschillende locaties, één in Limburg (480 dierplaatsen), de ander in Noord Brabant (750 dierplaatsen). In de eerste fase zijn de emissies, de bronnen en de eigenschappen van stof onderzocht en zijn de concentraties of aan-/afwezigheid van een aantal bacteriën in de lucht vastgesteld, waaronder die van C. burnetii. Aangezien de rapportage in mei 2011 afgerond moest zijn, zijn in dit onderzoek slechts metingen gedaan tijdens de najaar- en winterperioden.

For groups of pigs to cope adequately with their housing conditions they need sufficient static space (occupied by the body of the pig), activity space (for movement between different functional areas and behaviours relating to these) and interaction space (for appropriate social behaviour). Estimates for static space have been presented for thermoneutral conditions, but are expected to increase substantially as temperature increases. The present paper models the relationship between ambient temperatures above the comfort zone, and thermoregulatory lying behaviour in finishing pigs. Estimates of the effect of posture on floor occupation were obtained and presented as ‘k-values’ (k = floor area occupied (m2)/body weight2/3 (kg)) to correct for the effect of pig size. A literature review was conducted to collect information on three aspects of lying behaviour: lying frequency, posture (lateral, semi lateral or ventral lying) and level of space sharing (huddling) in response to increasing temperatures. The lowest and highest values found were: increase in lying down: 0.2–0.66%, reduction in space sharing: 1.7–4.9% and increase in lateral vs sternal lying: 0.8–2.3% per °C temperature increase. Extrapolation of k values in the comfort zone to T = 31 °C suggests a range of k-values from k = 0.0331 to k = 0.0385 for static space. In the second part of this paper we analyse video data from a pig building in which groups of 18 pigs were kept in large pens (1.67 m2 per animal) at temperatures ranging from 16 to 32 °C. We find a value of k = 0.0339 at T = 31 °C for static space, which is at the lower end of the range predicted from literature. A possible explanation for this relatively low additional space requirement is that the animals coped by increasingly using the slatted area (with sprinkler system) as a lying area. The study confirms earlier suggestions that the amount of space required by EU legislation is insufficient for pigs at the end of the finishing period, even at relatively low temperatures. In situations where the average room temperature exceeds the comfort zone, pigs need additional space to cope with their housing system, or alternative methods to cool themselves down.

In this study emissions of fine dust (PM10 and PM2.5) from layer houses with a manure drying tunnel were determined. In addition, emissions of ammonia, greenhouse gases and odour were determined. In dit onderzoek zijn de emissies bepaald van fijnstof (PM10 en PM2,5) uit leghennenstallen met een droogtunnel. Additioneel zijn de emissies van ammoniak, broeikasgassen en geur bepaald.

In an airborne transmission experiment, Campylobacter in the air was sampled by three types of bioaerosol samplers (all-glass impinger AGI-30, Andersen six-stage impactor, and OMNI-3000) in four broiler rooms. In each room, five 14-day- old broilers inoculated with Campylobacter jejuni were kept in a central cage located in the middle of the room. Another ten broilers, as susceptible animals, were kept individually in ten cages surrounding the central cage at a distance of approximately 75 cm. Air samples were taken on eight days: the day before inoculation (BI) as a negative control, and 1, 3, 6, 9, 14, 21, and 29 days post-inoculation (PI). Presence of C. jejuni was investigated with the culture method for culturable bacteria and with the PCR test for bacterial DNA. Results showed that Campylobacter infection of susceptible broilers occurred in all four rooms; however, no culturable C. jejuni could be detected in any of the air samples. This might have been the result of the low number of broilers in the room and the unfavorable conditions for Campylobacter survival, leading to Campylobacter concentrations below the detection limits of the bioaerosol samplers. The PCR test showed that DNA of C. jejuni was detected in the air samples on the first day PI, but no bacterial DNA was detected on the following days. It is concluded that the three samplers used in this study are not able to alarm Campylobacter outbreaks through an airborne route when low bacterial concentrations are present. Developments of new sampling techniques with low detection limits are required for biosecurity assessment.

In this study, the fine dust emission reduction of an oil spraying system was determined through validation measurements on broiler farms. In dit onderzoek is de fijnstofemissiereductie van een oliefilmsysteem vastgesteld door validatiemetingen op vleeskuikenbedrijven.

The effect of spraying rapeseed oil on the reduction of dust and ammonia concentrations and emissions, and on animal parameters was investigated in a dose-response study in a broiler house during three growing periods in four (round 1) or five rooms (rounds 2 and 3). The spraying rates varied per room, from 0 (control) to 24 mL oil m(-2) d(-1). Concentrations of PM10 and PM2.5 in incoming and outgoing air were measured. Production results (growth rate, feed intake, mortality rate) and foot-pad lesions were also determined. Regression analysis showed that a spraying rate of 6 mL oil m(-2) d(-1) reduced PM10 concentrations by 44% and PM10 emissions by 48%. At 24 mL oil m(-2) d(-1), the reduction was 82% for PM10 concentrations and 87% for PM10 emissions. For PM2.5, the lowest spraying rate of 6 mL oil m(-2) d(-1) was sufficient to reduce concentrations by 68% and emissions by 84%. The reduction achieved at higher spraying rates was not significantly greater. Emissions of PM10 and PM2.5 increased exponentially with the age of the broilers. A clear diurnal pattern was observed, with lower dust concentrations during the dark periods. Production results were unaffected by the spraying rate. A high rate of 24 mL oil m(-2) d(-1) increased the number and severity of foot-pad lesions. It is concluded that spraying rapeseed oil significantly reduces dust concentrations and emissions from broiler houses. To prevent adverse effects on broilers' foot-pad quality, it is recommended that the maximum rate should he 16 mL oil m(-2) d(-1).

The objective of this study was to evaluate the efficiencies and suitability of samplers for airborne microorganisms and dust, which could be used in practical livestock houses. Two studies were performed: 1) Testing impaction and cyclone pre-separators for dust sampling in livestock houses; 2) Determining sampling efficiencies of four bioaerosol samplers for bacteria and virus. Study 1. The overloading problem of the EU reference impaction pre-separator (IPS) was tested in layer houses and compared with cyclone pre-separators (CPS) for sampling PM10 and PM2.5. Study 2. Physical and biological efficiencies of Andersen 6-stage impactor, all glass impinger (AGI-30), high air flow rate sampler OMNI-3000, and MD8 with gelatin filter were investigated for collecting aerosolized bacteria, Enterococcus faecalis, Escherichia coli, Campylobacter jejuni and Mycoplasma synoviae and live Gumboro vaccine virus. A tracer (uranine) was used to determine physical efficiencies and bioaerosol deposition. The study was done in a HEPA isolator (volume: 1.3 m3). The results show the PM10 IPS did not become overloaded in 24 h measurements in layer houses, whereas PM2.5 IPS became overloaded within 1 h. CPS did not become overloaded during 48 h sampling of both dust fractions. The OMNI-3000 (62%) had lower physical efficiency than the MD8, while the other samplers had similar efficiencies as MD8. All the bioaerosol samplers had high biological efficiencies for all four bacterial species, except for C. jejuni (1%) when measured with the OMNI-3000 and for E. coli (38%) and C. jejuni (2%) when measured with the MD8. The biological efficiencies of the Andersen impactor (61%), the AGI-30 (90%) and the MD8 (163%) were not significantly different from 100% for collecting the aerosolized virus. However, the biological efficiency (23%) of the OMNI-3000 was significantly lower than 100%.

The first objective of this study was to measure the year round emissions of ammonia (NH(3)), nitrous oxide (N(2)O), and methane (CH(4)) from three commercial aviary systems with organic laying hen husbandry. The second was to determine the effect on NH(3), N(2)O and CH(4) emissions of varying removal interval when using manure belts. Emissions were computed from the ventilation rate, calculated with the carbon dioxide (CO(2)) mass balance method, and gas concentrations of NH(3), N(2)O, and CH(4) inside and outside the hen house. Mean emission per hen for NH(3) was 410 mg d(-1), for N(2)O was 3.12 mg d(-1), and for CH(4) was 81.7 mg d(-1). Mean predicted emission per hen for NH(3) on the first day after manure removal was 298 mg d(-1), and increased by 5.47% d(-1). The presence of manure on the belt did not affect emissions of N(2)O and CH(4). Emission of NH(3) from aviary systems with organic laying hen husbandry was in the same range as emission of NH(3) from aviary systems with non-organic laying hen husbandry. Using organic laying hen husbandry in aviary systems instead of single-tiered systems has the potential to reduce emissions of NH(3), N(2)O, and CH4; further reductions might be realised by changes in litter management. (C) 2011 IAgrE. Published by Elsevier Ltd. All rights reserved.

The knowledge on the contribution of individual sources to particulate matter (PM) in different size fractions is essential to improve PM reduction from livestock houses. We investigated which input data (particle chemical, morphological or combined characteristics) were best to distinguish amongst specific potential sources of PM. We used a cross-validation procedure with classification rules based on decision trees and analyzed misclassification errors. The PM from two livestock species (poultry and pigs), and in two different fractions (fine and coarse) was studied. A total of 618 particles were analyzed from poultry houses for fine, and 805 for coarse PM. A total of 317 particles were analyzed from pig houses for fine, and 337 for coarse PM. Results showed the selection of the best input data varies depending on the sources, which depend on livestock species. Using only particle chemical characteristics results in higher overall classification accuracies than using only morphological characteristics. Particle morphological characteristics can add value when sources show well defined morphologies or differ in size. Using combined particle chemical and morphological characteristics results in the highest overall classification accuracies (average of 69% of particles correctly assigned to their source). The approaches presented in this study are promising to determine the contribution of different sources to PM in livestock houses.

In this study, the fine dust emission reduction of a negative ionization system was determined through validation measurements on broiler farms. In dit onderzoek is de fijnstofemissiereductie van een negatief ionisatiesysteem vastgesteld door validatiemetingen op vleeskuikenbedrijven.

Dit rapport beschrijft een onderzoeksprogramma voor het terugdringen van fijn stofuitstoot uit pluimveestallen. Het plan van aanpak voor de ontwikkeling van concrete praktijkrijpe bedrijfsoplossingen wordt op hoofdlijnen beschreven met de randvoorwaarden. Daarnaast komen de deelprojecten met oplossingen die implementatierijp zijn in 2009 en in 2011 aan bod

The upcoming ban on battery cages in the European Union is expected to cause a shift in husbandry systems from predominantly battery cages to enriched cages and loose housing systems, such as barn, free range and organic systems. To gain insight into ecological and economic consequences of such a ban, we quantified the ecological and economic performance of the most commonly used egg production systems in the Netherlands, and identified which parameters explain differences in performance. We included the conventional battery cage system and the following loose housing systems: single and multi-tiered barn systems, single and multi-tiered free range systems, and single and multi-tiered organic systems. Ecological indicators used were deduced from a life cycle assessment, and were: global warming potential, energy use, land occupation, fossil phosphorus use, acidification potential, nitrogen and phosphorus deficit, and nitrogen and phosphorus surplus, each expressed per kg of egg. Economic indicator used was net farm income per full time employee. Based on our ecological evaluation of Dutch egg production systems, we predict that a ban on battery cages in the European Union will increase global warming potential, land occupation and acidification potential per kg of egg produced, whereas the effect on energy use, fossil phosphorus use, nitrogen and phosphorus deficit, and nitrogen and phosphorus surplus depends on relative importance of different loose housing systems. Of all loose housing systems, organic systems had lowest global warming potential, energy use, fossil phosphorus use, and nitrogen and phosphorus surplus, whereas land occupation and nitrogen and phosphorus deficit was lowest for barn systems. Acidification potential was lowest for a multi-tiered barn system. Differences in LCA results among production systems can be explained mainly by differences; in feed conversion, in parameters that determine ecological impact per kg feed ingredient (e.g., crop yield per ha; number field operations, type and amount of fertilization), in drying of grain, in transport of concentrates and manure, in type of hen house and in N excretion per hen per year. Free range systems had highest net farm income, followed by organic systems. Multi-tiered systems had a higher net farm income than single-tiered systems. In case differences among egg and cost prices of different systems do not change after a ban on the battery cage, multi-tiered free range and organic systems are economically most favourable.

The feasibility was studied of producing algae on compounds in the exhaust air of pig houses. The application of ventilation air in algae growing systems will not lead to a significant decrease of production costs of algae. De haalbaarheid van algenkweek op componenten in de uitgaande lucht van varkensstallen is onderzocht. Het toepassen van stallucht in kweeksystemen voor algen zal niet leiden tot een aanzienlijke verlaging van de kweekkosten van algen.

Two studies were conducted to assess the efficiency of air scrubbers to reduce airborne microorganisms in the exhaust air from animal houses. First, in a field study, the effects of a bio-scrubber and an acid scrubber on total bacterial counts were assessed. Higher bacterial counts were found in the outlet air compared to the inlet air of a bio-scrubber (increase from 6.1 × 104 to 2.4 × 105 CFU m-3), while an acid scrubber with sulfuric acid reduced bacterial emissions from 2.7 × 105 to 8.4 × 104 CFU m-3. Second, in a laboratory study, the effects of three disinfectants, added to the circulating water of an experimental air scrubber, on reductions of bacteria and virus were tested and compared with the effect of using only water. The air to the scrubber was extracted from four isolators each harboring seven roosters. Enterococcus faecalis and Gumboro vaccine virus were aerosolized in the air of one of the isolators. Hydrogen peroxide (H2O2; 0.6%), peracetic acid (CH3CO3H; a solution of 0.13% acetic acid, 0.6% peroxide, and 0.13% peracetic acid), or ozone (O3; 0.015%) were used as disinfectants. Peracetic acid was the only disinfectant that reduced bacteria and virus concentrations to below the sampler detection limits. We conclude that an acid scrubber with sulfuric acid is very useful at reducing ammonia emissions to the atmosphere but cannot significantly prevent emissions of microorganisms. Peracetic acid has a high potential to reduce these emissions and could replace or supplement sulfuric acid in existing scrubbers during periods of high risk of disease outbreak.