Browsing by Subject "Ventilation"

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Vergleich von zwei Haltungssystemen für Mastschweine mit unterschiedlichen Lüftungsprinzipien - Stallklima und Emissionen
(2003) Gallmann, Eva; Jungbluth, Thomas
The main goal of this work was to carry out a system comparison of two different housing systems for fattening pigs with regard to indoor climate and the gas emission and to derive a corresponding data basis in the frame of long-term measurements with a high temporal resolution. The housing systems to be compared were a conventional stable with fully slatted floor and a conversion solution designed as a kennel housing system with natural ventilation. The system comparison of the two different housing systems for fattening pigs was carried out in two spatially separated compartments of the experimental pig facility for fattening pigs in Hohenheim. During the investigations the conventional practical housing system served as reference system and featured fully slatted floor, six small groups with nine pigs each, forced ventilation with underfloor extraction. As comparison system a conversion solution for forced ventilated pig houses was developed and realized. It was designed as a kennel housing system with separate climatic areas and with natural ventilation. The kennel housing system consisted of two larger animal groups with 24 pigs each, it showed slatted floor at the activity area and a level concrete covered lying area for resting. The natural ventilation system in the kennel housing system was designed as a gravity shaft system with an additional, solar-powered fan in one chimney for optional supporting ventilation. No differences between the housing systems existed concerning feeding (sensor liquid feeding, four-phases nutrient adjusted feeding), occupation, demanuring, stocking management (all in - all out) and the animals origin. The relevant measuring parameters for evaluating the indoor climate and gas emissions as temperature, humidity, ventilation rate, gas concentrations (NH3, CO2, CH4), animal activity, wind speed and wind direction were registered with a high temporal resolution. In addition at regular intervals also manure samples were analysed, dust concentration measurements were carried out as well as data concerning the floor soiling, the animal weight, weight gain and feed conversion ratio were documented. Between the housing systems "fully slatted floor, forced ventilation (FSF)" and "kennel housing, natural ventilation (KN)" a clear difference existed concerning the indoor climate mainly due to the different ventilation systems. At both housing systems the indoor concentrations of NH3, CO2 and CH4 were acceptable, but at the same time lower at system KN than at system FSF, so it can be concluded, that the air exchange in the animals area was sufficient. Inside the kennels of the system KN the air quality was strongly dependent on the soiling with animals´ droppings, especially during warm days, when the pigs tend to switch the functional areas. Depending on the temperature and given the lower resting area requirements of the younger animals, some of the covered resting areas were heavily soiled. The indoor dust concentrations (PM 10; PM 2,5; PM 1,0) were during all measurements about two third lower at system KN than at system FSF. For all data sets a negative correlation between dust concentration and air flow rate per livestock unit LU (500 kg live weight) was determined. At both housing systems the dust concentrations during feeding were due to the increased animal activity two to six times higher than between the feeding times. Comparing the mean emission rates of NH3, CO2 und CH4, significant differences between the housing systems with entirely lower emission rates of the natural ventilated system KN were found during all four fattening periods under investigation. Due to manifold dynamic interrelations between the different influencing factors on the emissions at such complex systems as animal houses, also significant differences between the fattening periods within one housing systems were found. Therefore a seasonal effect on the emissions could not be proven on basis of the gained data sets. Considering both the daily mean values and typical daily courses of the gas emissions, different relationships between air flow rate, exhaust air concentration and emission were found between the two housing systems. At the forced ventilated housing system FSF as a result of increasing air flow rates the exhaust air concentrations were lowered (diluting effect) but the emissions raised up. At the natural ventilated housing system KN the relations were not always clear or opposite effects were observed. Increasing air flow rates resulted partly in just as increased exhaust air concentrations but following lower emissions. At both housing systems short emissions peaks of NH3 and CO2 can be explained by an increased animal activity during feeding.