Lack of effect of aerial ammonia on atrophic rhinitis and pneumonia induced by Mycoplasma hyopneumoniae and toxigenic Pasteurella multocida

Micro- and Macroenvironmental Conditions and Stability of Terrestrial Models

Environmental variables can have profound effects on the biological responses of research animals and the outcomes of experiments dependent on them. Some of these influences are both predictable and unpredictable in effect, many are challenging to standardize, and all are influenced by the planning and conduct of experiments and the design and operation of the vivarium. Others are not yet known. Within the immediate environment where the research animal resides, in the vivarium and in transit, the most notable of these factors are ambient temperature, relative humidity, gaseous pollutant by-products of animal metabolism and physiology, dust and particulates, barometric pressure, electromagnetic fields, and illumination. Ambient temperatures in the animal housing environment, in particular those experienced by rodents below the thermoneutral zone, may introduce degrees of stress and thermoregulatory compensative responses that may complicate or invalidate study measurements across a broad array of disciplines. Other factors may have more subtle and specific effects. It is incumbent on scientists designing and executing experiments and staff responsible for animal husbandry to be aware of, understand, measure, systematically record, control, and account for the impact of these factors on sensitive animal model systems to ensure the quality and reproducibility of scientific studies.

Yearly emission factors of ammonia and particulate matter from three laying-hen housing systems

The aim of the present study was to measure the concentration of ammonia and particulate matter (PM) that passes through a size‐selective inlet with a 50% cut‐off at 10-μm aerodynamic-equivalent diameter (PM10) and emissions into atmosphere in the following three types of laying-hen houses: traditional battery cages with aerated open-manure storage (BSP) and two best available technique (BAT) housing types, namely, an aviary-system housing (ASH) and a vertical tiered cage with manure belts and forced-air drying (VTC). Measurements were taken continuously for a period of 1 year in each house. Ammonia concentration was measured continuously in each house using an infrared photoacoustic detector with a 15-min sampling interval. PM10 was measured continuously using a scatter light photometer, corrected by the traditional gravimetric-technique concentration to lower the measurement error. The same instrument was also used to collect PM10 through a traditional gravimetric technique. This procedure was performed to adjust the particulate matter-specific gravity of PM that is typical and specific for every animal house. PM10 and ammonia measurements were carried out together with measurements of inside and outside temperature, inside and outside relative humidity and ventilation rate. For the high PM10 concentrations measured in the ASH house during a preliminary survey, concentrations of total suspended particles (TSP) and fine PM (particles <2.5 microns) were also measured to evaluate the dustiness in the building during the working hours. The ammonia concentration was 5.37 mg/m3 in the traditional BSP house (the reference for cage-housing system), 4.95 mg/m3 in the VTC and 3.85 mg/m3 in the ASH. The ammonia-emission factors were 15.445 mg/h.hen place (0.135 kg/year.hen place) for BSP, 8.258 mg/h.hen place (0.072 kg/year.hen place) for VTC, and 23.704 mg/h.hen place (0.208 kg/year.hen place) for ASH. Ammonia emission-reduction efficiency of VTC v. the BSP was 53%, according to thresholds assessed by Integrated Prevention Pollution Control. The ammonia-reduction efficiency of ASH v. that of the standard Reference Housing system for non-cage housing was 68%. Average yearly PM10 concentration was remarkably higher in the ASH, with 0.215 mg/m3 v. 0.108 mg/m3 for the VTC and 0.094 mg/m3 for BSP. In the ASH, the concentration of total suspended particles (TSP) was 0.444 mg/m3 and that of PM2.5 was 0.032 mg/m3. In this facility, a great variation of PM10 concentration occurred in the morning hours. Recorded values for the PM10 emission were 0.433 mg/h.hen for BSP and 0.081 mg/h.hen for VTC, while the ASH showed the highest PM10 emission (1.230 mg/h.hen), with clear peaks occurring in the morning hours during daily farming operations.