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Prairie Swine Centre is an affiliate of the University of Saskatchewan
Prairie Swine Centre is grateful for the assistance of the George Morris Centre in developing the economics portion of Pork Insight.
Financial support for the Enterprise Model Project and Pork Insight has been provided by:
Denitrification in a Coastal Plain Riparian Zone Contiguous to a Heavily Loaded Swine Wastewater Spray Field
Posted in: Environment by admin on January 1, 2004 | No Comments
Production responses of weaned pigs after chronic exposure to airborne dust and ammonia.
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Nine hundred and sixty weaned pigs were exposed for 5.5 weeks to controlled concentrations of airborne dust and ammonia in a single, multi-factorial experiment. Production and health responses were measured but only the former are reported here. The treatments were a dust concentration of either 1.2, 2.7, 5.1 or 9.9 mg/m3 (inhalable fraction) and an ammonia concentration of either 0.6, 10.0, 18.8 or 37.0 p. p. m., which are representative of commercial conditions. The experiment was carried out over 2.5 years and pigs were used in eight batches, each comprising five lots of 24 pigs. Each treatment combination was replicated once and an additional control lot (nominally approx.0 mg/m3 dust and approx.0 p. p. m. ammonia) was included in each batch to provide a baseline. The dust concentration was common across the other four lots in each batch in which all four ammonia concentrations were used; thus the split-plot design was more sensitive to the effects of ammonia than dust. The pigs were kept separately in five rooms in a purpose-built facility. The pollutants were injected continuously into the air supply. Ammonia was supplied from a pressurized cylinder and its concentration was measured with an NOx chemiluminescent gas analyser after catalytic conversion. The endogenous dust in each room was supplemented by an artificial dust, which was manufactured from food, barley straw and faeces, mixed by weight in the proportions 0.5:0.1:0.4. The ingredients were oven-dried, milled and mixed and this artificial dust was then resuspended in the supply air. Dust concentration was monitored continuously with a tribo-electric sensor and measured continually with an aerodynamic particle sizer and gravimetric samplers. Live weight per pig and cumulative food intake per pen of 12 pigs were measured after 5.5 weeks of exposure. Exposure to both aerial pollutants depressed live weight relative to the control (control v. pollutant, 25.7 v. 25.0 (s.e.d.=0.33) kg, P=0.043) and there was a trend for food intake to be lower for pollutant-exposed pigs (control v. pollutant 292 v. 280 (s.e.d.=7.1) kg per pen, P=0.124). The reduction in live weight and food intake was dependent upon the concentration of dust (mean across all ammonia concentrations for increasing dust concentration; live weight 25.3, 26.4, 24.0 and 24.5 (s.e.d.=0.65) kg, P=0.081; food intake 295, 316, 248 and 263 (s.e.d.=14.3) kg per pen, P=0.016) but not ammonia (mean across all dust concentrations for increasing ammonia concentration; live weight 24.4, 25.1, 25.3 and 25.3 (s.e.d.=0.41) kg, P=0.158; food intake 279, 275, 288 and 279 kg (s.e.d.=9.0) kg per pen, P=0.520). There was an interaction between dust and ammonia for live weight (P=0.030) but the effects were complicated and may have been the result of a type I error. There was no interaction for food intake (P=0.210). In general, both food intake and live-weight gain, but not food conversion efficiency, were lower for weaned pigs exposed to 5.1 and 9.9 mg/m3 dust concentrations compared with 1.2 and 2.7 mg/m3 treatments. Other measures of production were also analysed and supported the overall interpretation that dust concentrations of 5.1 mg/m3 and higher depress performance. This study is the first to quantify the effects of chronic exposure to common aerial pollutants on the performance of weaned pigs. The results suggest that dust concentrations of 5.1 or 9.9 mg/m3 (inhalable fraction) across ammonia concentrations up to 37 p.p.m. adversely affect performance. The commercial significance of these findings depends on the financial benefits of the superior production at low dust concentrations relative to the cost of providing air of this quality.
DE: air-pollutants; air-pollution; ammonia-; dust-; exposure-; feed-conversion-efficiency; feed-intake; liveweight-gain
Community-Based Strategies for Resolving Agricultural and Land Use Conflict
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Design and Testing of an Enclosed Biofilter
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Biofiltration of odourous air from livestock barns using a horizontal airflow configuration
is possible. During the course of this research, two possible designs have been evaluated.
A pressurized headspace design functioned well, but may not be practical for a full-scale
commercial hog operation. Using the principle that “simpler is better”, a biofilter using a
non-pressurized headspace seems to eliminate some of the practical challenges associated
with the pressurized headspace design. Looking to the future, I see two potential applications of horizontal airflow biofilters. First, as we have demonstrated in this project, is a retrofit situation where the exhaust air from an existing barn is to be treated. I envision that individual biofilter units would be constructed in a factory setting and then transported to the barn for installation and
filling. Each biofilter unit could be custom-designed to either the airflow requirements of the exhaust fan, or the odour reduction desired by the owner. Construction of the units would be quick, easy, and inexpensive at a central, factory-like location. The dimensions of the units are such that they could be transported on a flat-deck trailer. Further work must be done to determine the best way to install the units within the limits imposed by insurance companies. The second potential application of a horizontal airflow biofilter is the integration of the biofilter with the barn at the time of construction. Specifically, the integration of the exhaust fan and the booster fan. By considering both the ventilation requirements for air quality within the barn and the airflow resistance characteristics of the biofilter, a single fan could be selected to satisfy both functions. With such integration at the design stage, there should be no need for insurance companies to be uptight about the presence of a
biofilter. During this project, much has been learned about the technology of biofiltration. At the
same time, much has been learned about the non-technical issues associated with biofiltration of hog odour. As evidenced by the response to the open house event, the general public is extremely interested in biofiltration if it can make the smell go away. Those within the hog industry are somewhat interested, but seem to be more skeptical. Companies that design livestock facilities are beginning to take notice of the technology because it may help to remove roadblocks to new expansion within the hog industry. Municipal officials are watching closely. And finally, the insurance companies are
concerned about increased liability.
Land Application of Manure
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Odours, dust from road traffic and potential soil and water contamination are often associated with land application of manure. These issues can be addressed effectively through proper management techniques and through an awareness of cropping principles and environmental regulations.