Continuous odour measurement from fattening pig units

peer reviewedA study in experimental slatted-system fattening pig units was conducted with the aim of estimating the odour emission factor (in ou/s.pig), which can subsequently be used in dispersion models to assess the odour annoyance zone. Dynamic olfactometry measurements carried out at different development stages of pigs showed a logical trend of the mean predicted odour emission factor with the pig weight. However, the variation within the same weight class was much larger than variation between classes. Possible causes of such variation were identified as the evolution of ventilation rate during the day and the circadian rhythm of pig. To be able to monitor continuously the daily variation of the odour, an electronic nose was used with suitable regression model calibrated against olfactometric measurements. After appropriate validation check, the electronic nose proved to be convenient, as a complementary tool to dynamic olfactometry, to record the daily variation of the odour emission factor in the pig barn. It was demonstrated that, in the controlled conditions of the experimental pens, the daily variation of the odour emission rate could be mainly attributed to the sole influence of the circadian rhythm of pig. As a consequence, determining a representative odour emission factor in a real case cannot be based on a snapshot odour sampling

Emissions of ammonia, nitrous oxide and methane from pig houses: Influencing factors and mitigation techniques

info:eu-repo/semantics/publishe

Terorizem (in zapiranje Guantanama)

info:eu-repo/semantics/publishe

Ammonia emissions from pig houses: Influencing factors and mitigation techniques

Pig houses are important sources of ammonia (NH3) emissions. For decades, investigations were carried out in determine the influencing factors and to point out opportunities of mitigation. In Europe, current NH3 emissions associated to pig production are about 24% lower than in 1990. However, further reduction seems necessary to avoid noxious effects on ecosystems. The main factors influencing NH3 production are the floor type, the manure removal system, the climatic conditions inside the building, the diet composition and the feed efficiency of animals. In pig production, the main floor types are the slatted floor and the bedded floor systems. In both systems, numerous variants and adaptations can be found with consequently a range of emission levels for each housing condition. Therefore, decision in favour of a floor type as regards NH3 emissions is difficult, especially as effective reducing strategies are available for both systems. For litter-based systems, the nature and the amount of substrate greatly influence the NH3 production with usually lower emission in case of generous bedding. For slatted floor systems, most of the studies resulted in lower emissions with partly slatted floor on condition that the solid part of the floor remains clean. Indeed, hot conditions, high animal density or inadequate pen design can increase the soiling of the solid floor and lead to increased NH3 emissions. In any case, emissions are lower if concrete slats are replaced by smooth materials like iron cast, metal or plastic slats. Several slurry pit designs and manure removal strategies were developed to mitigate emissions. The reduction of the slurry pit surface thanks to sloped pit walls are related to proportional reductions of NH3 emissions. Frequent manure removal, flushing and separating urine from faeces by V-shaped scraper or conveyor belts reduce the NH3 releases from the buildings by about 50%. However, the emissions during the storage period outside the building have to be taken into account for a whole assessment of the technique. Climate conditions inside the building also influence the emissions which are positively correlated with ambient temperature and ventilation rate. Consequently, ammonia emissions present seasonal and nychtemeral patterns. But, reducing the NH3 production by modulation of the climate conditions is rather unpractical because the ambient parameters must primarily respect the bioclimatic requirements for animal comfort. A closer match between dietary intakes and requirement of the pigs according to the physiological and growth stage results in lower NH3 emissions. In this way, diets with reduced crude protein content are highly effective in reducing the emissions with almost a 10% reduction for every 10 g kg−1 reduction in dietary crude protein. Other dietary strategies are also effective in lowering emissions. Dietary fibre inclusion reduces NH3 emissions by about 40% by shifting the nitrogen from urine to faeces due to promotion of bacterial growth in the large intestine. Lowering the dietary electrolyte balance or supplementation with acidifying salts like benzoic acid or CaSO4 are related to significant reductions. Other feed additives like Yucca extract, zeolites, probiotics, humic substance or lactose were also validated by several experiments. Moreover, better feed efficiency obtained by genetic selection or modification of the hormonal status of the pigs is also related to reduced emissions. In conclusion, effective reduction of ammonia emissions from pig buildings can be reached operating both on housing conditions and feeding strategies. The former are very efficient but the assessment has to include the specificity of each system and involve the complete process. In some cases, investment and cost operating can hamper their development. Feeding strategies offer the advantage of being easy to implement and rapid to adapt function of particular circumstances

Effets de la surface disponible et du type de sol sur les émissions gazeuses lors de l’élevage de truies gestantes

peer reviewe

Ammonia and greenhouse gas emissions during the fattening of pigs kept on two types of straw floor

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Effet des fibres dans l'alimentation des truies gestantes et des porcs charcutiers sur les émissions d'ammoniac et de gaz à effet de serre

peer reviewedThis study aims to measure under barn conditions the emissions of NH3, N2O, CH4 and CO2 associated with gestating sows (trial 1) and fattening pigs (trial 2) fed either by a control diet (CTD) based on cereals or a high-fibre diet (HFD) based on sugar beet pulp (SBP). Three successive batches of 10 Belgian Landrace gestating sows were used for trial 1. Two successive batches of 24 Piétrain x Belgian Landrace fattening pigs were used for trial 2. Animals were kept on slatted floor. The gas emissions were measured by infrared photoacoustic detection and expressed per day and per livestock unit (LU, equal to 500 kg body weight). Similar trends were observed for both animal types. With HFD, NH3 emission was reduced (27.2 vs. 36.5 g/LU for the gestating sows, P0.05), and on CO2 emission (around 6.0 kg/LU for gestating sows and 9.1 kg/LU for fattening pigs, P>0.05)