Verdamping uit ligbodems van vrijloopstallen : oriënterende modelberekeningen = Water evaporation from bedding in dairy cattle freestall barns : model approach

Water evaporation from bedding in freestall dairy cattle houses was modeled. Calculated water evaporations from excreta in composting and non composting beddings were much lower in Holland than in Israel. A model approach to study the drying potential of bedding materials in freestall dairy cow barns under Dutch climate conditions was performed. Water evaporation from bedding in freestall dairy cattle houses was modeled. This was done as part of a feasibility study of freestall barns with different beddings under Dutch meteorological conditions. The beddings are made up of mixtures of soft composting, or non composting materials and animal excreta. Two available models on composting and drying were combined. The estimated water flux from urine and feces that is excreted on the bedding was integrated in the model approach. Model calculations were performed to compare the order of magnitude of evaporation from the bedding area under Dutch, Israeli and Minnesotan climate conditions and at 18 versus 9 m2 of bedding area per animal. Calculated water evaporations from excreta in composting and non composting beddings were much lower under Dutch weather conditions than under Israeli conditions. The calculated evaporation under cold Minnesotan winter conditions was lower and in hot Minnesotan summer was higher than under Dutch conditions. The calculated evaporation from a bedding that is composting was higher than from a non composting bedding. The calculated rate of composting was strongly dependent on the heat flux that results from conversion of organic matter and the heat loss from the bedding. The heat flux is strongly influenced by the air velocity above the bedding. High air velocities result in a large heat loss that may slow down or even inhibit the thermophylic composting process. The lower evaporation rate of inorganic beddings may be compensated to some extend by increasing the air velocity above the bedding. To keep the top layer of the bedding sufficiently dry it may also be searched for a bedding with a high fluid infiltrating capacity. By adding fresh bedding material or controlled drying of part of the bedding material outside the barn problems during adverse climate conditions may also be tackled. On farm pilot experiments with bedding materials and management are needed to test whether or not it is possible to keep the top layer of the bedding at an acceptable level of dryness under cold and moist Dutch weather condition

Stofniveau biologische varkensstal onveilig hoog

Biologische varkenshouders werken vaak langdurig in de stal vanwege de grote zorg voor de dieren. Daarnaast is strooisel een vereiste in de biologische varkenshouderij. Dit leidt ertoe dat biologische varkenshouders aan hoge stofconcentraties worden blootgesteld. Wageningen UR Livestock Research onderzocht samen met biologische varkenshouders hoe hoog de stofbelasting is en hoe zij zich tegen het stof kunnen bescherme

Blootstelling aan fijnstof in de biologische varkenshouderij = Exposure to fine dust in organic pig farming

In deze studie zijn metingen verricht van de persoonlijke blootstelling aan fijnstof tijdens het werk op drie biologische varkensbedrijven. Uit de resultaten blijkt dat biologische varkenshouders bloot staan aan fijnstofconcentraties die aanzienlijk hoger zijn dan geadviseerde streefwaarden. Dit rapport geeft praktische aanbevelingen aan biologische varkenshouders om de blootstelling aan fijnstof tijdens het werk te verlage

Plan van aanpak bedrijfsoplossingen voor fijn stofreductie in de pluimveehouderij

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 bo

Ammonia emission from houses for growing pigs as affected by pen design, indoor climate and behaviour

The ammonia volatilization in pig houses should be reduced to protect the environment and to improve the air quality inside the house. The objective of this study was to examine the effects of various housing factors and animal behaviour on the ammonia volatilization in houses for rearing and fattening pigs. The study was intended to yield ways that pig farmers could reduce the emission of ammonia by combining effective and economic housing measures. A marked increase was found in the ammonia emission during the growing period of the pigs. Ammonia emission was generally higher during the summer than the winter season and was positively related to the urine-fouled floor area and the frequency of urination. Reducing the slatted floor and slurry pit area and using slatted floors of smoother material and with more open space than concrete slatted floors, lowered the ammonia emission. The air quality was improved by using a ventilation system with a low air inlet in the floor of the feeding passage and a low outlet just above the slatted floor, instead of a high diffuse inlet and a high outlet. The ventilation system did not affect the total emission of ammonia. The ammonia emission could be reasonably well predicted with a dynamic numerical model at the low and moderate levels of emission, but was poorly predicted at high levels of emission. It is concluded that by combining simple housing measures it is possible to reduce appreciably ammonia emission from houses for growing pigs at relatively low costs. Furthermore, animal welfare and health and the working conditions of the stockman can be improved by these measures.Ph.D. thesis, Institute of Agricultural and Environmental Engineering (IMAG-DLO), department of Livestock Engineering, P.O. Box 43, 6700 AA Wageningen, the Wageningen Institute of Animal Sciences (WIAS) and the Department of Agricultural Engineering and Physics of the Agricultural University Wageningen.This study was financially supported by FOMA (Financieringsoverleg Mest- en Ammoniakonderzoek). Their contributions are gratefully acknowledged

Maatregelen ter vermindering van fijnstofemissie uit de pluimveehouderij; deskstudie naar mogelijke toevoegingen aan de oliefilm

In this desk study it was determined which additives are suitable for the oil in the oil film system to reduce ammonia and odour emissions

Algenkweek op stallucht = Cultivation of algae on ventilation air from animal houses

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

Integrated ecological hotspot identification of organic egg production

Ecological sustainability in agriculture is a concept that contains various environmental problems, which are caused by emission of compounds during different processes along the food chain. A precise ecological analysis of farming systems and food chains is needed in order to suggest and implement effective measures to improve sustainability. Life Cycle Assessment (LCA) assesses the environmental impact along the entire chain. In this research, LCA was used to locate environmental hotspots within the organic egg production chain and explore options that substantially improve ecological sustainability using sensitivity analysis. The environmental impact was expressed per kg of organic egg leaving the farm gate. Five environmental impact categories were included: 1) climate change i.e., emission of CO2, CH4 and N2O, 2) eutrophication i.e., emission of NH3, NOx, N2O and leaching of NO3 - and PO4 -, 3) acidification i.e., emission of NH3, NOx, and SOx, 4) fossil energy use i.e., oil, gas, uranium and coal and 5) land use. In case of a multifunctional process, economic allocation was used. We interviewed 20 out of 68 Dutch organic egg farmers to collect farm data for 2006. Data on transport, feed, rearing and hatching were gathered by the conduction of interviews with suppliers and from literature. The Life Cycle Inventories of electricity, natural gas, tap water, transport and cultivation originated from the Eco-Invent V2.0 dataset. A sensitivity analysis was executed for production parameters from the laying hen farm. To identify hotspots, the relative contribution of transportation, feed production, rearing and hatching and the laying hen farm, as well as the contribution of various compounds to each impact category was determined. We identified a chaincompound combination as a hotspot if it contributed to more than 40% of the total of the environmental impact category. Results showed four hotspots. First, 62% of climate change was caused by emission of N2O from soils during growing of feed. Second, 57% of acidification was caused by NH3 emission from the laying hen farm. Third, 47% of energy use was oil used for cultivation of feed and fourth, 95% of the land use was arable land required for feed production. We identified no hotspot for eutrophication, but feed production contributed most with 37% nitrogen leaching and 26% PO4 - leaching. From the sensitivity analysis it appeared that the most sensitive parameters on an organic laying hen farm are the number of produced eggs, the amount of feed consumed and the housing system. An increase in average egg production from 276 with a SD of 39 eggs per laying hen reduced climate change with 13%, acidification with 15%, eutrophication with 13%, energy use with 12% and land use with 12%. A reduction in average annual feed consumption from 42.9 kg with the SD of 7.2 kg per laying hen reduced climate change with 14%, acidification with 17%, eutrophication with 15%, energy use with 14% and land use with 13%. A shift from deep litter housing to an aviary housing with manure drying reduced climate change with 11%, acidification with 53%, eutrophication with 18% and had no effect on land use. The effect on energy use is still being assessed. We conclude that feed conversion and housing are effective ecological optimization options for organic laying hen farmers. However ecological sound feed production also needs attention

Maatregelen ter vermindering van fijnstofemissie uit de pluimveehouderij: labproef karakterisering van olievernevelaars (druppelgrootte en snelheid) = Measures to reduce fine dust emission from poultry houses : laboratory study: characterizing oil spraying nozzles (droplet size and velocity)

Two spraying nozzles have been studied with respect to droplet size and velocity of the sprayed rapeseed oil depending on the applied liquid and air pressures. For the nozzle with a wide angle round spray the air pressure should be lower than the oil pressure and should be in the range of 1.5 and 2.5 bar. For the flat spray nozzle the variation in droplet size is small and the oil and air pressure may vary between 2.0 and 3.0 ba

Maatregelen ter verminderding van fijnstofemissie uit de pluimveehouderij; factorenstudie stofemissie bij verschillende volièresystemen

Uit verschillende volièresystemen emitteren verschillende hoeveelheden fijnstof. Uit de factorenstudie blijkt dat dit niet veroorzaakt wordt door de verschillende lay-out van de systemen maar veel meer door de kwaliteit van het strooise