Characterization of particles, ammonia and endotoxin in swine confinement operations.

Posted in: Environment by admin on January 1, 1993 | No Comments

Total and respirable dust particles, ammonia and endotoxin were measured in the nursery and grower areas of 4 swine confinement houses during January-March and April-June. Increased ventilation in the spring-summer relative to that in winter reduced concentrations of large dust particles more rapidly than it did smaller particles and ammonia. The greater decrease in large particles correlating to increased room air velocity may reflect the momentum of larger particles causing impaction on surfaces. There was a significant spatial variation in the concentration of airborne endotoxin within individual swine rooms and pens reflecting different mixing of large feed and smaller manure particles. Smaller particles had a 4-fold higher concentration of endotoxin than did larger particles, suggesting they had higher faecal material concentrations. Total airborne endotoxin and total suspended particulates correlated to the fraction of functional endotoxin contained in large particles, suggesting that small particles (0.5-2.0 um) collide with large particles (50 um). These results indicate that large non-respirable particles remove smaller respirable particles from indoor atmospheres due to kinematic coagulation.

Loss of Nitrogen from Pig Slurry to Ammonia Volatilization and Nitrate Leaching

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The authors present an important literature review. When considering ammonia emissions, all means to reduce direct contact of manure with air, covers during storage and incorporation or injection of manure and rapid infiltration when spreading will lower the emissions. The leaching will be controlled when manure is applied the closer in time to the growth period.

Nitrogen Balance in the Case of Slurry Separation on the Farm

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For sedimentation, the addition of poly-electrolyte accelerate considerably the sedimentation process (2 to 3 days) compared to at least 20 days for temperatures above 16 C. The mechanical separation could not reduce sufficiently the dry matter content of the liquid fraction (1-2% lower compared to the effluent) to make this type of technology economically attractive. The separation system under the slats presented technical problems (brake down of the scraper, clogging of the urine outlet).The three separation systems showed disappointing results in this experiment. The performances obtained do not justify the investment costs of such systems.

Relationship Between Concentration and Intensity of Odours for Pig Slurry and Broiler Houses

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PENETRATION AND PRESSURE DROP OF A HEPA FILTER DURING LOADING WITH SUBMICRON LIQUID PARTICLES

Posted in: Air Filtration, Pork Insight Articles by admin on June 30, 1992 | No Comments

Researchers have created experiments and a model has been developed to measure the effects of mass loading a High-Efficiency Particulate Air (HEPA) fiber filter during filtration of sub-micron liquid aerosol particles. It was found that penetration of the test medium increased during clogging by a liquid aerosol, and this was irrespective of particle size. The affect was not changed by the physicochemical properties of the test aerosol. Application of a non-stationary filtration model shows that the increase in penetration is in part caused by an increase in interstitial velocity and in part by a decrease in the number of fibers available for capture of particles.

Effects of filtration, vacuum cleaning and washing in pighouses on aerosol levels and pig performance

Posted in: Air Filtration, Pork Insight Articles by admin on March 9, 1992 | No Comments

In order to reduce human and pig exposure to aerosols in pig housing units three techniques have been developed and tested. The techniques are: Filtration and recirculation of air in weaner rooms, weekly vacuum cleaning in a finishing house and weekly washing with water of weaned piglets. All the experiments were carried out on 70-92 pigs. The air filtration study was replicated seven times, the vacuum study was replicated two times and the washing study was replicated six times. In the air filtration study gravimetrical dried aerosol concentrations was reduced 40%. Although this did not result in significant changes to feed intake or daily gain for the pigs during the weaning stage. The vacuum study was able to improve reduction of aerosol particles by 10% after four days. Although no impact was made on feed intake or daily gain. But, pigs in a room that was not vacuumed had more veterinary treatments for respiratory health disorders. For the washing study aerosol particles were reduced 10%, and on the day of washing it was reduced 25%. Again there were no significant improvements to pig performance. The researchers conclude by saying that the costs of implementing these aerosol concentration reduction techniques do not compensate for the  pig performance improvements that they yield.

Effects of pen size, partial stalls and method of feeding on welfare-related behavioural and physiological responses of group-housed pigs

Posted in: Welfare by admin on February 10, 1992 | No Comments

A factorial experiment was carried out to see how welfare was effected, both long and short-term, by pens size and pen design. The experiment used mated gilt pigs in groups of four. The pigs were unfamiliar with each other and were put through six treatments which were combinations of either large or small pens (1.97 m² per pig or 0.98m² per pig) and pens with or without feeding stalls  and with stall feeding or floor feeding. Pigs were video taped and analyzed on aggressive behavior such as biting and butting. They were watched in the first 90 minutes they were grouped and after that during feeding periods on certain days. Also pigs were inspected for lesions before treatment and during treatment. Pigs were assessed for cortisone levels to determine the long term effects of stress. In the initial 90 minutes, pen size had no effect on the amount of aggressive behavior, also pen design had little effect on aggression. Around feeding the large pen had less incidence of aggression. Pen design also had impacts on aggression, in the treatment with stalls and when the stalls were used, it was found that there was reduced aggressive behavior. While pens without stalls and the use of floor feeding had the most aggressive behavior. Cortisone levels were seen to improve in bigger pens and pens designed with stalls and when stalls were used. Pen size or pen design had no effect on lesions. The article concludes to say there are potential welfare improvements that can come from pen size and pen design but further research is needed to find what pen design and management practices are ideal. Also more research is required to find what behavioral and physiological parameters should be used to measure welfare.

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Fast, Automated Testing of Different Air Filter Media

Posted in: Air Filtration, Pork Insight Articles by admin on January 29, 1992 | No Comments

Air filters are used for many different purposes in many different fields. Two different air filter categories are high efficiency particulate air (HEPA) filters which are used in clean room technology, and the other category, gas cleaning filters are used in emissions control and also in vacuum cleaners. HEPA filters usually are able to contain 99.97% of all particles over 0.1 µm in diameter. Gas filters accuracy varies between 0-100% efficiency with particles sizes between 0.3 µm and 100 µm. The fractional penetration measurement and the measurement of the pressure drop is key for describing the characterization and quality control for both filters. To test this a procedure was developed and two test rigs were built. By simultaneously measuring the fractional penetration and the pressure drop, loading studies can be done in a few mlnutes. Face velocity, upstream concentration, test dust material, filter material and electrostatic charge of the particles and fitter fibres can show influence under varying conditions. The study goes on to discuss the time and size dependent penetration and pressure drop of electret fibre, glass fibre, and paper media.

A Mathematical Model for Estimating the Amount and Composition of Slurry from Fattening Pigs

Posted in: Environment by admin on January 1, 1992 | No Comments

As models are a representation and simplification of the reality, specific and complex interactions between factors are difficult to evaluate and to integrate in a model. This model could be of interest when investigating the effect of different diet formulation on the manure production and the nutrient excretion.

A Review of the Control of Odour Nuisance from Livestock Buildings: Part 2, The Costs of Odour Abatement Systems as Predicted from Ventilation Requirements

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English pound (L).