Baseline emission values of greenhouse gases were not well established for commercial poultry barns in cold regions, including Canada, due to a lack of well-designed field studies. Emission factors of carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O), were acquired for a commercial broiler barn and cage-layer barn in the Canadian Prairies climate. Between March 2015 and February 2016, monthly measurements throughout the year for the layer barn and over 6 flocks for the broiler barn, and diurnal measurements in the mild, warm, and cold seasons for both barns were conducted, respectively. The ventilation rate was estimated based on a CO₂ mass balance method; thus CO₂ emissions were quantified by the CIGR (2002) models. The CH₄ and N₂O emissions present at low levels from global perspective for both barns; the cold climate proved to be a major reason for the lower CH₄ emission from the layer barn. Considerable seasonal effect was observed only for N₂O emissions from the broiler barn, and for CH₄ and N₂O emissions from the layer barn, both with higher emissions in the mild and warm seasons than in the cold season. The big diurnal variations of CO₂ emissions for the layer barn demonstrated the uncertainty of the seasonal results by snapshot measurements and correction factors (from −20.9% to −22.5%) were obtained. Besides, the difference of CH₄ and N₂O concentrations and emissions as well as CO₂ concentrations between best-case (the first day after manure removal) and worst-case conditions (the last day before manure removal) was not obvious for the layer barn. Additionally, changes of temperature and ventilation rate were likely to have more impact on N₂O emission for the broiler barn and more impact on CH₄ emission for the layer barn than on the other two gas emissions, both with positive correlations.

This study investigated particulate matter (PM) loading rates and concentrations in ambient air from naturally ventilated dairy barns and also the influences of pertinent meteorological factors, traffic, and animal activities on mass loading rates and mass concentrations. Generally, relationships between PM2.5 concentration and these parameters were significantly poorer than those between the PM loading rate and the same parameters. Although ambient air PM2.5 loading rates correlated well with PM2.5 emission rates, ambient air PM2.5 concentrations correlated poorly with PM2.5 concentrations in the barns. A comprehensive assessment of PM2.5 pollution in ambient air, therefore, requires both mass concentrations and mass loading rates. Emissions of PM2.5 correlated strongly and positively with wind speed, temperature, and solar radiation (R2 = 0.84 to 0.99) and strongly but negatively with relative humidity (R2 = 0.93). Animal activity exhibited only moderate effect on PM2.5 emissions, while traffic activity did not significantly affect PM2.5 emissions.

Air pollutants accumulated in confined livestock barns could impact the health of animals and staff. Particulate matter (PM) and ammonia (NH3) concentrations are typically high in enclosed livestock houses with weak ventilation. The objective of this study was to investigate the distribution of PM in different size fractions and the levels of NH3 in a high-rise nursery (HN) barn and a high-rise fattening (HF) barn on a swine farm and to analyse the physicochemical properties of fine PM (PM2.5, PM with aerodynamic diameter ≤ 2.5 μm). The concentrations of total suspended particles (TSP, PM with aerodynamic diameter ≤ 100 μm), inhalable PM (PM10, PM with aerodynamic diameter ≤ 10 μm), PM2.5 and NH3 were monitored continuously for 6 d in each barn. The results showed that the concentrations of PM and NH3 varied with position, they were significantly higher inside the barns than outside (P < 0.01) and significantly higher in the forepart than at the rear of the two barns (P < 0.05). In the HF barn, the values of the two parameters were 0.777 ± 0.2 mg m−3 and 26.7 ± 7 mg m−3, respectively, significantly higher than the values observed in the HN barn at all monitored sites (P < 0.05). The PM concentrations increased markedly during feeding time in the two barns. Chemical characteristics analysis revealed that the main sources of PM2.5 in the two barns may have consisted of blowing dust, feed, mineral particles and smoke. In conclusion, the air quality at the forepart was worse than that at the rear of the barns. Activities such as feeding could increase the PM concentrations. The components of PM2.5 in the two barns were probably blowing dust, feed, mineral particles and smoke from outside.

This research investigated the use of two relatively cost-effective devices for determining NH3 concentrations in naturally ventilated (NV) dairy barns including an Ogawa passive sampler (Ogawa) and a passive flux sampler (PFS). These samplers were deployed adjacent to sampling ports of a photoacoustic infrared multigas spectroscope (INNOVA), in a NV dairy barn. A 3-day deployment period was deemed suitable for both passive samplers. The correlations between concentrations determined with the passive samplers and the INNOVA were statistically significant (r = 0.93 for Ogawa and 0.88 for PFS). Compared with reference measurements, Ogawa overestimated NH3 concentrations in the barn by ∼14%, while PFS underestimated NH3 concentrations by ∼41%. Barn NH3 emission factors per animal unit (20.6–21.2 g d⁻¹ AU⁻¹) based on the two passive samplers, after calibration, were similar to those obtained with the reference method and were within the range of values reported in literature.

Understanding how artificial light at night (ALAN) impacts wildlife is increasingly important because more and more species are colonizing urban areas. As most of the bird studies on ALAN use controlled light set inside or around nest-boxes, the ecological effect of ALAN resulting from in situ streetlight on birds remains contentious. The barn swallow (Hirundo rustica) often builds open nests on buildings, which are directly exposed to varying intensity of ALAN, and thus provides a good system to examine the effect of in situ ALAN on birds. By examining the nest-site selection, reproductive success and behavior of barn swallows under various ALAN intensity in Taipei City, we found a positive effect of ALAN on their fledging success; nonetheless, such effect was only found in the swallows’ first brood, but not second one. We also found that parent birds in the nests with higher ALAN intensity had higher feeding rates and more extended feeding time past sunset, which were likely stimulated by the increased begging behavior of their chicks. The night-feeding behavior might contribute to the increased fledging success, especially at the early breeding season. Interestingly, despite of the reproductive benefits obtained from ALAN, we found that the barn swallows did not select nest sites regarding ALAN intensity. The weak nest-site selection perhaps result from the complex life history interactions involving ALAN and/or confounding factors associated with ALAN in cities. This study improves our understanding of how urban birds, especially open-nesting ones, respond to in situ ALAN and provides useful information for developing urban conservation strategies.

Animal agricultural activities can be a significant source of pollutants affecting the health of farmers and neighboring communities. The main objective of this research was to improve the air quality by reducing the interior concentrations of emitting pollutants such as particulate matter (PM) and ammonia (NH3) within forced-ventilated fattening pig barns in order to improve the working conditions for human and the living conditions for animals as well as to have less impact on the surrounding environment. The mitigation techniques were a recirculating air scrubber and spraying of a water-oil mixture. The reduction efficiencies of the two mitigation techniques for PM and NH3 concentrations inside the barns were investigated. Two air scrubbers were mounted in a barn occupied with 515 pigs. A water-oil mixture spraying system with two different nozzles geometries was installed in a barn with 680 pigs. The data obtained from the mitigation system was compared with that obtained from a control barn with the same animal capacity and conditions. The results indicated that the average reduction efficiencies were 63% for total PM, 61% for PM10 and 32% for NH3. The results indicated that the average reduction efficiencies of the spraying system for the whole periods were 74% for total PM, 72% for PM10 and 19.5% for NH3 when using small nozzles and 44% for total PM, 39% for PM10 and 16% for NH3 when using large nozzles. The spraying system reduced the germs and fungal spore concentrations by 14 and 58%, respectively.

The adverse effects of air emissions from animal feeding operations (AFOs) on public health, environment, and quality-of-life have been well-documented. Regulations or lawsuits may force AFOs to reduce their air emissions. Since livestock barn particulate matter (PM) has relatively high particle density and diameter and many gasses adsorb onto PM, its filtration might reduce air emissions. A porous windbreak wall that imposes acceptable backpressure (< 12.5 Pa) and covers the fan could be a promising option. Seventy-two different porous windbreak wall scenarios were modeled to compare their backpressure on the fan as well as average airspeed over the ground. These scenarios were combinations of shape (box, chamfered, curved), size (lengths of 2, 2.5, and 3 fan diameters), presence or absence of an opening (opened and closed), screen porosity (mosquito screen or clean screen, SunBlocker 70% or clogged screen), and fan angle and height. Backpressure and airspeed decreased with increasing windbreak wall length. Generally, the box-shaped windbreak wall had lower backpressure and airspeeds than the other shapes. The increased backpressure with clogged screen even at two fan diameters (2d) was acceptable. The tilted fan commonly used in poultry houses had higher backpressure and airspeed over the ground than the non-tilted fan used in swine houses due to the former’s lower surface area and tilt towards the ground. Overall, taking into account cost considerations and footprint size (for retrofittability), despite its higher airspeed over the ground (vs. larger footprints) and modest reduction in airflow rate, the 2d, open box model seems the most promising option.

Dairy cows are responsible for significant emissions of enteric methane (CH₄) and produce nitrous oxide (N₂O) and ammonia (NH₃) gas from manure. As an abatement strategy, we explored the effects of long-term condensed tannin (Quebracho and chestnut extracts) addition to dairy cow diets. Previous studies have demonstrated that tannins in cow diets reduce methane and ammonia efflux, but none have done so over a >1-month time period. A modified stanchion barn equipped with gas analysis instrumentation measured CH₄, N₂O, and NH₃ fluxes into and from the barn, at the onset of the experiment, and 45 and 90 days after feeding groups of lactating dairy cows a control diet or two levels of tannin extract at 0.45 and 1.8 % of dietary dry matter. Few statistical differences among treatments were observed, likely a consequence of high variability and low sample size necessary for conducting a study of this duration. However, on a per-cow basis, low and high tannin diets lowered CH₄ emissions by 56 g cow⁻¹ day⁻¹ and by 48 g cow day⁻¹, respectively. Diet tannin additions lowered CH₄ (33 %), NH₃ (23 %), and N₂O (70 %) per unit milk corrected emissions in the high tannin treatment compared to the control at the end of the experiment, without significant loss in milk production. These results suggest that relatively low concentrations of diet tannin additions can reduce ruminant CH₄ and gaseous N emissions from manure. The tannin effect observed after 90 days is a starting point for considering tannin additions as a potential long-term strategy for improving the environmental footprint of milk production.

Odor concentrations (OC) and emissions (OE) were measured for a commercial broiler barn and a cage-layer barn in a cold region (the Canadian Prairies). Seasonal OC and OE profiles were plotted by monthly measurements over the course of a year from March 2015 to February 2016, and diurnal profiles were generated by 2-day measurements in cold, mild, and warm seasons, respectively. Seasonal OC and OE varied for both barns; OC was higher in the cold season, but OE was higher in the mild and warm seasons. The broiler barn had higher annual average OC (718 OU m⁻³) but slightly lower annual average OE (127 OU s⁻¹ AU⁻¹; AU is per 500 kg of body mass) than the layer barn (574 OU m⁻³ and 140 OU s⁻¹ AU⁻¹). For the layer barn, OC and OE were reduced by 31% and 33% in the cold season and by 30% and 26% in the mild season after manure removal compared with before manure removal. Statistical results showed increased outdoor temperature and ventilation rate (VR) were associated with decreased OC but increased OE for both barns. Finally, both single linear and multi-linear regression models of OE were developed.

Air emissions from animal feeding operations (AFOs) can affect public health, environment, and quality of life. Although regulations or lawsuits may force AFOs to reduce air emissions, treatment options are limited and expensive. Trapping particulate matter (PM) emitted from AFOs is important for reducing emissions since many odorous and environmentally important gases are also transported on PM. Since PM emitted by AFOs have relatively high particle density and diameter, its partial filtration might be feasible and effective in reducing air emission. A porous windbreak wall made of lumber and mosquito screen, coupled with a vegetative strip of switchgrass (Panicum virgatum) covering three fans, was evaluated in a tunnel-ventilated swine finishing barn. The system imposed acceptable pressure on the fan (< 13 Pa) and was readily cleaned by rain. The system reduced total suspended particulate (TSP) emission moderately (average reduction of 28%), while reduction in ammonia emissions was low. Odor 10 m downstream of the fans was reduced greatly by 71%. Soil inside the system and vegetation accumulated appreciable amounts of nitrogen and sulfur; the vegetation also trapped appreciable amounts of PM. Overall, this low-cost, retrofittable, and modular system could be used by swine farmers to reduce their emissions, alone or in combination with other mitigation methods to obtain greater reduction in emissions.