A note on the effect of deep-litter housing on growth performance of growing-finishing pigs

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

Deep-litter can be an alternative for liquid manure and for improvement of the pig’s welfare. The litter used was sawdust and the performances of the pigs on deep-litter were slightly higher. The author attribute this improvement to better thermal comfort of the animal as they lay on a warm surface rather than directly on concrete. The microorganisms activity of the litter result in an increase in temperature of the material. However, if we set aside the reduction of the manure volume obtained when using the deep-litter, more important losses of nitrogen is done to the atmosphere under the form of NH3 but also N2O and NOx (composting process) than for liquid manure systems.

Effect of porcine somatotropin and dietary protein level on the nitrogen losses of pigs.

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The use of somatotropin is not allowed presently in Canada. However the results on N retention obtained with the use of this hormone are very interesting and could lead to better overall performances and reduction of the N excreted. The cost involved with the use of this hormone is not given.

Reduction of Ammonia Emission from Slurry by Application of Liquid Top Layers

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The experiments were done in a laboratory. It must be reminded that the figures given consider only the ammonia emission reduction from the manure pit which represents only a source of emission in the building (wet or soiled floor or slats are also ammonia sources). More work as to be done on real scale to determine the best type of liquid to be used on economical and environmental points of view and also the best manure removal techniques that would retain the top liquid layer in the pit.

The Fate of Nitrogen in Pig Slurry Applied to a Pasture Soil in New Zealand

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The manure applied was analyzed and the total N content equaled 1420 mg N/kg of slurry; ammonium-N was 1200 mg/kg and nitrate-N was 0 mg/kg. Ammonia losses occurred within the first seven days following application. The application rates equivalent to 200 kg N/ha for the slurry used equals to 140 ton slurry/ha and for 600 kg N/ha to 425 ton slurry/ha.

Effect of three protein feeding strategies, for growing-finishing pigs, on growth performance and nitrogen output in the slurry and in the air

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An efficient way to reduce the N excretion in the manure (-23% in this study) as well as N gaseous emissions from the building (-25%) is to lower the protein supply in the diet of growing-finishing pigs and improve the amino acids balance.

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

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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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Using swine dust to verify a lumped-parameter model in a ventilated enclosure.

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Pig dust was used as a test dust to verify a lumped-parameter model derived for predicting airborne dust concn at any location within a ventilated airspace. Average equilibrium airborne dust concentrations were predicted as a function of ventilation and dust generation rates. Time-dependent airborne dust concentrations at a designated location (or control volume) were also predicted from ventilation and dust generation rates. The model calculation, solved as a 3-D lumped form of control vol., represented conservation of air mass flow rate. Pig dust used in this project had an av. aerodynamic diam. of 2 mum, 95% of the dust particles were less than 5 um in diameter and approx. 45% of the particles were 2 um in diameter. Both ventilation rate and dust generation rate have a significant effect on airborne dust concentration. The lumped-parameter model is shown to be capable of predicting the ventilation rate required to maintain acceptable levels of airborne dust in animal housing. The accuracy of the model is influenced by the test dust particle size uniformity.