Pathology and handling of poultry at the slaughterhouse.

Posted in: Welfare by admin on January 1, 1994 | No Comments

Field Evaluations of a Low Energy Swine Nursery Facility

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Transport of pathogens through soils and acquifers.

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Between 1971 and 1980, the use of untreated groundwater was responsible for more than one-third of the waterborne disease outbreaks in the United States. This statistic points to the potential for subsurface contamination by pathogenic microorganisms. The major sources of pathogens are waste water effluents, residual sludges from waste treatment, and septic tank effluents. The number of septic tanks in the United States has been estimated at 22 million units. These on-site treatment systems serve approximately one-third of the U.S. population. They are major contributors to the contamination of subsurface environments. The contaminants are household chemicals (nitrate, heavy metals, organic toxicants), pathogenic microorganisms in soils and aquifer material is primarily governed by their transport and persistence in these environments. The survival and transport of pathogens in soils and aquifers are controlled b four major factors: climate (e.g. temperature, rainfall), type of soil or aquifer material (e.g. texture, pH, water holding capacity, cation exchange capacity), properties of pore fluids (e.g. chemistry, saturation), and type of pathogen. In the following sections, we review the major factors controlling the persistence and transport of pathogens and discuss modeling efforts to assess pathogen fate in soil andsubsurface environments.

Modelling the Performance of a Non-steady State Continuous Aeration Plant for the Treatment of Pig Slurry.

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Modelling has been used to study and understand better the process occurring during manure aeration. The simulation showed that problems could be expected if the temperature in the digestor decreased under 10 C in cold winter conditions and the temperature reached 47 C were the microbial activity would be affected during hot summer.

Olfaktometrie – Bestimmung der hedonichen Geruchswirkung – Olfactometry – Determination of Hedonic Odour Tone

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To evaluate an highly odorant substance or source other parameters than the odour threshold have to be considered such as its effect for above threshold concentrations on the olfactory sensation and its hedonic odour tone. The Guideline presents a method for evaluating the hedonic odour tone of odorant air mixes or gases . The hedonic odour tone of an odour should not be confused with the odour quality (referring to fragrant, stale, pungent or such) and is, in the guideline, represented by a position on a scale from 4 which is an extremely pleasant odour to -4 representing an extremely unpleasant one with 0 being neither pleasant nor unpleasant. VDI 3881 and VDI 3882 should be used for odorant concentration and odour intensity determinations. The procedures are given to realize the hedonic odour tone measurements and the results evaluation and presentation. The hedonic odour tone has to be considered in odour abatement evaluation as reduction of the odorant emissions intensity may not always results in improvements of the hedonic odour tone. To evaluate a nuisance situation, frequency and duration of odorant presence in the ambient air have also to be considered.

This guideline gives interesting information and definitions of an important aspect of nuisance coming from odour which is the hedonic odour tone. Olfactometry methods are used to evaluate many parameters characterizing odours that are more oriented in quantity evaluation. These procedures can be applied to pleasant odour sources or substances in the same way than for unpleasant odour source. The hedonic odour tone evaluation gives information on the human emotional reaction to odour which is essential in odour evaluation and abatement.

Pre-slaughter diets affect meat quality

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The influence of oral acid or base load on the processing quality of hams from halothane positive (HP) pigs was examined. HP pigs received either ammonium chloride (8g/L), sodium bicarbonate (12.6g/L) or no additive (HP control) pigs were also slaughtered. Meat from HP animals showed pale, soft exudative properties and was of inferior processing quality to hams of normal quality from HN pigs. Ammonium chloride induced a metabolic acidosis, which further impaired ham quality. Hams from ammonium chloride treated HP hogs had greater thaw purge, less uniform slice appearance and were less juicy than comparable hams from control or bicarbonate treated HP hogs.

Handling and transport of spent hens.

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Natural Ventilation – 10 years later

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Natural ventilation has become a very viable alternative to fan ventilation for growing and finishing pigs. Like many newer technologies, it has had its problems and is following a typical learning curve. However, it is here to stay and will likely increase in popularity with rising energy costs and an increased use of straw bedded, group housing arrangements. Today’s naturally ventilated barn is quite a bit different than the early 80’s model. Sidewall and ridge openings are discussed along with controls for natural ventilation and building location.

Lung function in a five-year follow-up study of farmers

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Traitement du lisier de porc par aeration-sedimentation – Suivi de l'evolution physico-chimique en pilote.

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Experiments were done in order to verify the feasibility and performances of a continuous aeration and sedimentation process for swine manure. The tests were realized on a pilot scale setting with two reactors of 1 cubic meter where aeration was done. Three different aeration and retention time treatments were tested: 1 1/2 day with high aeration rate, 1 1/2 day with low aeration and 4 days with low aeration. During the experiment, the temperature in the reactors is maintained between 25 to 35 C. As it is a continuous process, every hour, some treated manure is put in the sedimentation bin for 48 hours if the retention time in the reactor is 4 days and 18 hours for the retention time of 1 1/2 days. The aeration treatments showed that the volatile fatty acids were importantly lower (reduction of 99,5%), the chemical oxygen demand was also reduced by more than 40% and the nitrogen was removed by 15 to 47% (the operation conditions of the reactor have to be well controlled in order to limit the losses by NH3 and N2O). At the end of the sedimentation stage, the sludge obtained represents 37% of the initial volume and contains the main part of the insoluble elements. The treatment deodorize the manure and the liquid part could be used for crop irrigation as it is still charged with nutrients.

No information is given on the level of deodorization. No information is given on the economics of such systems. Two products have to be disposed and evaluated for their nutrient content and two different types of equipment may be needed to handle the liquid part and to handle the sludge.