Influence de l'alimentation et des performances sur les rejets azotes des porcs

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An improvement in the productivity of the pig production (increase in the number of piglets produced per year, a better feed conversion ratio, improvements in the herd health) has a direct effect on the nitrogen excretion as the animals become more effective in their feed utilization.

Respiratory Health-Status in Swine Producers Relates to Endotoxin Exposure in the Presence of Low Dust Levels

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An assessment, including questionnaire and spirographic measurements, was conducted on the respiratory health status in 54 male swine producers, aged on average 36.3, who worked an average of 10.7 years in the industry and spent on average 4.7 hours per day in the swine barns. Atmospheric contaminants were measured including carbon dioxide, ammonia, total dust, respirable dust and airborne endotoxin. Respiratory symptoms and lung function studies did not relate to categories of low, medium and high exposure to respirable dust. The data suggest that respiratory health status relates to endotoxin levels but not to dust level exposures in the presence of low dust levels and indicates that control measures should include endotoxin as well as dust control.

Analyse des chantiers d'epandage des fumiers et lisiers pratiques dans l'Ouest de la France

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The value of animal excretion is increasingly appreciated by the farmers. To give a better control of the manure value through application, a thorough analysis of the elements around manure handling and spreading on the farm was done by the FRCUMA (a regional union of cooperatives of agricultural machinery users). The following elements were taken into account in the study: distances between the manure storage facilities and the fields where the manure is applied, spreading systems, actual application rates compared to the rates that are intended by the farmers, and fertilizing value of the manure applied. The factors affecting application rates are also presented.

Livestock wastes are often perceived as wastes and should be considered as a resource. However to reach this change in mentality, means have to be considered in order to understand all the elements such as technical, economical, psychological and social aspects contributing to practices evolution. In studying contract or cooperative manure spreading, consideration have to be put to technical, economical and labor aspects.

Farmer's Options to Reduce Odour and Ammonia Emissions from Animal Buildings and Storage

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For farmers, it is interesting to control ammonia and odour with a single measure. However, ammonia and odours have different impact regarding the environment thus the motivation for investments from farmers to control ammonia or odour are different. In the Netherlands were animal density is high, the control of both odour and ammonia became necessary as for other countries with lower animal density, odour is the first priority. As most measures to reduce emissions are not economically profitable, attention has to be given on measures that are applied where the emissions are important, as for the Netherlands the manure landspreading representing 1/2 the ammonia emission and a high proportion of the odour complaints. More effective proteins feeding will have an impact on the N excretion as urea and uric acid, thus lowering the ammonia concentration and emission. Housing systems that limits emission have also to be considered and the way manure is stored has also an impact. Outside manure tanks would be a better measure in reducing ammonia emission than in reducing odour emission. Housing systems with litter would result in odour control by lowering odor emission but not in the total N emissions (less ammonia but more NO, N2O than standard systems). Manure treatment have an effect on the emission however as anaerobic digestion reduces odour emission, it doesn’t reduce ammonia emission and as acidification prevent the ammonia emission, it has little effect on odor. Measures that reduce ammonia emission cannot be automatically considered as being effective in odor reduction and conversely. The control of ammonia has to be regulated otherwise the farmers tend to consider odours as a higher priority.

This article gives a general view of the situation and means to reduce ammonia and odour emissions. The need for regulation on ammonia control is stressed as it is generally costly and odour control is consider the first priority with its direct impact on the neighborhood.

Respiratory symptoms and bronchial reactivity among pig and dairy farmers

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Cyclone design for axial-flow fan exhaust systems.

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The utilization of new cyclone design methodology has resulted in the development of a 1D-2D cyclone design with a 2D-2D inlet, a 1D-3D outlet, an enlarged dust outlet of D/2, and a larger outlet tube diameter of D/1.6. This design has exceeded preliminary goals of a maximum 623 Pa pressure drop and minimum 80% collection efficiency as a fine dust and fine dust/trash collector. This design may facilitate the need for an improved air abatement device for the first-stage lint cleaner.

Engrais organiques et amendements : vers la maitrise de l'epandage.

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The CEMAGREF is implicated with the machinery industry to help them evaluate and improve the spreading systems they put on the market in order to improve the accuracy of the application for the application rate and transversal and longitudinal uniformity. However no specific information is given on the steps and measures taken for this evaluation.

Reduction of Ammonia, Compared with Odour Concentration on Pig and Poultry Farms

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Experiments were done on a pig farm and included about 4850 piglets 24-86 days old and on a broiler chicken farm including about 16000 animals. The possibilities of reducing ammonia and odours by using “deodorase” additives in the feed and in slurry were investigated. Ammonia, hydrogen sulfide as well as other micro-climatic elements have been measured and olfactometric measurements have been done to determine the odour concentration obtained with the use of the additive (165g/t in prestarter feed, 65g/t for the grower and 15g/m3 slurry) compared to a control group. The results showed that for the pigs, the ammonia reduction was about 59% (significant at P<0.001) and the odour reduction was 22% but with no significant difference with the control group. It was found that there were differences in the reduction of ammonia and olfactometric values obtained between the pig and poultry farms (where for poultry the ammonia was reduced by 28% and the odour by 19.7%). No information was given on the economical part of the additive use. The performance regarding odour cannot be considered in this experiment because no significant difference with the use of the additive (the difference of 22% could come from other experimental procedures and not necessarily from the additive). Even if the experiment was done with a large number of pigs, the experiment was not repeated.

A LAND-LIMITED AND ENERGY-SAVING TREATMENT SYSTEM FOR DILUTE SWINE WASTEWATER

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Numerical simulation of particle transport in slot-inlet ventilated airspaces.

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Numerical simulation of particle transport in slot-inlet ventilated air spaces was conducted to determine the influence of exhaust placement, inlet placement, obstruction, and number of inlets on particle transport. Air flow was simulated using the 2-equation k-epsilon turbulence model and particle transport was calculated using the equation of motion of the particle. Results showed that the vertical position of the exhaust outlet on the sidewall did not significantly influence particle transport. Vertical position of the inlet significantly influenced particle transport; however, results did not show any considerable difference in particle concentration with inlet placement. Obstruction also significantly influenced particle transport: mean particle concentration at animal height was lower for all flow cases with no obstruction than for all flow cases with an obstruction. Results also showed that using a slot inlet on both sidewalls was more effective in removing or exhausting particles than using a slot inlet on 1 sidewall only.