Effect of Pelleting Mixed Feeds on Phytase Activity and the Apparent Absorbability of Phosphorus and Calcium in Pigs

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The conditions during pelleting are determinant for diets that contain phytase. Temperature that reaches 80 C or more during the pelleting process of the diet results in a reduction of the digestibility of the P. Results showed that diets that contained phytase after steam pelleting presented the same P digestibility than diet that was phytase-inactivated. Not only the digestibility of P was decreased by pelleting but also the calcium digestibility was also lowered. Consequently, pelleting at high temperature has to be avoided.

Reducing dust levels in a livestock barn by the addition of canola oil to the feed.

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Dust particle counts, airborne dust mass concentrations, and amounts of settled dust were monitored during a 12 weeks study in a pig feeder barn. Particle counts were converted to particle production rates per kilogram of pig mass to account for changes in ventilation rate and number of animals. The effects of adding rapeseed oil to the feed and 2 flooring types (partially slatted and fully slatted floor) were investigated. Dust production rates indicated a high degree of variation over time. When rapeseed oil was added to the feed there was no significant decrease in airborne respirable particle production rates, but a significant decrease in the dust mass concentration and in the amount of settled dust. There was no significant difference in dust levels for the 2 types of flooring.

The Effect of the Plane of Nutrition on the Optimum Dietary Amino Acid Pattern for Growing Pigs

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The experiment determined an optimal ratio for amino acids to improve the digestibility of diets of growing pigs. As many of those experiments, a small group of animal was used. The addition of those amino acids improve the protein quality and the protein level of the diet can be lower without lowering the performances. As a consequence, the N excretion is lower.

Air filtration in a piggery: Filter design and dust mass balance.

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The design principles of internal recirculating dry air filters for use in livestock buildings are discussed and several designs described. In one design for a flat-deck early-weaner room a centrifugal rotor draws air through a floor-standing pre-filter and discharges it through a fine filter at a velocity of about 0.4 m/s. The fine filter constitutes the under-surface of a duct located above the pigs. The air throughput of the filter is equal to the max. ventilation rate of the room in order to achieve adequate dust reduction. When used in flat-deck rooms with early-weaner pigs, the filter unit reduced dust mass and bacterial colony-forming particle concn. by 50-60% and collected dust at daily rates of 100-500g per 100 piglets, depending on the design of the room and the age of the pigs. The pre-filter was periodically vacuum cleaned and the changes in pressure losses across the filters recorded for several weeks. The airborne dust concn. in a flat-deck room with a wire-mesh pen floor was only one-quarter of that in a room with similar stocking and ventilation rate with a solid floor. Measurements of dust deposition rate suggest that it is approx. proportional to the airborne dust concn. A theory is proposed which relates dust concn. to ventilation, filtration and deposition rates and accounts for the reductions in dust concn. achieved by the filtration described above. Calculations suggest that, under certain conditions, sedimentation can clear as much as 74% of the dust mass and of the number of particles generated and that this value is normally likely to exceed the percentage cleared by ventilation. It is probable that a floor of high voidage reduces dust because of the combined effects of a reduction in floor-generated dust and the voids providing a clearance path.

The Economic Potential of Feedlot Wastes Utilization in Agricultural Production

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Airborne microbial contents in two types of swine confinement buildings in Quebec.

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Two farrowing units housed 400 pigs each, and two fattening units housed 800 and 400, respectively; temperatures were controlled and the relative humidity was similar in each unit. Six-stage samplers collected microorganisms every 2 weeks for 6 visits from January to April; 4 and 20 minutes, respectively, were optimum for the total fraction and respirable fraction. The average airflow in the samplers was 28.3 litres/minute at 1 m above ground in the central aisle. The flow rate for dust sampling by filters was 2 m/minute for 1 hour. The total bacterial count was higher in the fattening houses. Averages of 48%, 15%, 52% and 19%, respectively, of total bacteria, gram-negative bacteria, fungi and yeasts of the farrowing units were in the respirable size range of < 5A

Ecological Analysis of a Cluster of Villages Emphasising Land Use of Different Tribes in Meghalaya in North-east India

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Nitrogen Losses during the Storage of Liquid Livestock Manures

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The experiment was realized in laboratory under controlled conditions and with small samples (5 – 12 kg/pot). Additives (sugar-beet vinasses, microbial additive, commercial Agriben, bentonite, pharmaceutical mixture and biodynamic preparation) were used with no significant effect on ammonia emission. The storage time however had a significant effect on the nitrogen losses.

Bronchial hyperreactivity among pig and dairy farmers

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Questionnaire evaluating organic dust exposure

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