One of the harmful substances produced by livestock manure is ammonia (NH3), which is emitted at a high rate. Additionally, NH3 reacts with sulfur oxides (SOx) and nitrogen oxides (NOx) in the atmosphere to produce fine particulate matter (PM2.5). However, the management and countermeasures for NH3 in livestock facilities were found to be inadequate. To establish effective measures, an NH3 emission factor that complies with certified methodologies is required. This study calculates the emission factor by monitoring NH3 concentration and ventilation between September 2022 and May 2023 in a mechanically-ventilated enclosed facility. The data measurement was performed in accordance with the VERA test protocol from Europe, and NH3 concentrations were monitored in real-time using photoacoustic spectroscopy measurement equipment. The average NH3 concentrations for Rooms 1, 2, and 3 during the entire period were measured at 0.96 ± 0.39 ppm, 1.20 ± 0.57 ppm, and 1.34 ± 0.71 ppm, respectively, with an overall average of approximately 1.17 ± 0.49 ppm. The average ventilation was recorded at 2,782.0 ± 1,510.4 m³/h, with an average internal temperature of 26.0 ± 1.5 °C and a relative humidity of 63.9 ± 5.2%. The average emission factor per room was calculated as 0.14 ± 0.03 g/day/pig for Room 1, 0.19 ± 0.07 g/day/pig for Room 2, and 0.15 ± 0.05 g/day/pig for Room 3. Ultimately, this study determined the average NH3 emission factor for the weaned pig facility to be 0.16 g/day/ pig.

This study was conducted to secure basic data for developing technologies to reduce the generation of odor substances by investigating the effects of environmental temperature on growth performance and the generation of odor substances from feces in growing pigs. A total of 16 pigs (Landrace × Yorkshire × Duroc, average body weight 56.49±0.47kg) were randomly assigned to two treatments: thermal-neutral (TN) and heat stress (HS) conditions. The experiments were conducted for two weeks, with average temperature-humidity indices of 68.91±0.09 for TN and 85.98±0.08 for HS. The results showed that HS significantly decreased average daily feed intake (ADFI, 33.3%) and average daily gain (ADG, 25.8%) compared with TN (p<0.05). Non-esterified fatty acid in serum was lower (36.2%) in HS compared with TN (p<0.05). However, protein, blood urea nitrogen, cholesterol, triglyceride, glucose, and IgG in serum showed no difference between HS and TN. Phenol (350.0%) and skatole (416.3%) were significantly higher in HS than in TN (p<0.05). The decrease in growth performance is attributed to reduction in ADFI. The increase in phenol and skatole in HS is presumed to be due to the effect of HS on the metabolism of intestinal microbial composition. Digestion rate, intestinal microbial composition, and urine emissions are known to affect odor substances. Further research on the content of odor substances in urine, nutrient digestion rate, and intestinal microbial composition is considered necessary to determine the exact associations.

This study evaluated the effectiveness of odor reduction when spraying inside the Bio-curtain (hereinafter referred to as curtain) according to the exhaust fan operating rate. Spraying is a main factor affecting the ability to odor reduction of curtains. The curtain (total area: 37.9m3) was constructed with two layers of light-shielding screens stretched over a rectangular parallelepiped structure installed around an exhaust fan (630 mm) on the side wall of a pig barn. Air samples for odor analysis were collected from inside the pig barn and outside the curtain. The main odorous compounds such as volatile fatty acids, phenols, indoles, and ammonia were measured. The odor reduction effectiveness was evaluated by total odor activity values (TOAVs) summed to the odor activity values of each odorous compounds. Depending on the exhaust fan operating rate, the reduced rate of TOAVs gradually decreased to the range between 15.67% and 68.80%. Because the contact time between the spraying liquid and the air velocity of the exhaust fan becomes shorter (or there is a reduction in liquid to gas flow ratio) as the exhaust fan operating rate increases. The results of this study can be used as basic data for research into spraying conditions to improve the odor reduction effectiveness of curtains.

The sampling bag is used as a storage container for odor gas samples. It is known that the substances recovery rate of odor bags decreases during storage time, and the degree of recovery varies depending on the characteristics of the gas sample and the material of the bag. This study investigated the recovery rate of VFA (ACA, PPA, BTA, VLA) in PEA bags during storage time. In addition, a model was developed to estimate the recovery rate of each substance as a function of time. Standard gas (ACA, PPA, BTA, VLA mixed) recovery rate was used for the model development. The concentration of the compound in the bag was measured by SIFT-MS at intervals of 1 to 2 hours. The recovery rate according to the storage time was calculated as the ratio to the initial concentration. The recovery rate of each substance according to the storage period (12h, 24h, 36h, 48h) was ACA (66.2%, 62.8%, 55.6%, 52.0%), PPA (77.6%, 72.1%, 63.0%, 58.1%, 86.6%), BTA (86.6%, 81.3%, 71.6%, 66.9%), VLA (94.8%, 89.0%, 76.6%, 71.7%). The recovery rate continued to decrease over the course of 48 hours of storage time. ACA, PPA, and BTA showed the greatest decrease within the initial 12 hours, which is form of exponential decrease. Therefore, we considered a 1~3 degree polynomial regression model and a 1~2 degree exponential decay model. Each developed model was evaluated by r², RMSE, MAPE, AIC, and then a model for each substance was selected. Selected models were tested with recovery rate data from swine farm odor samples. Only the ACA model exhibited a good performance (r² = 0.76).

Several analytical measurement techniques have been developed over the years for ammonia (NH3). However, the field monitoring of NH3 still remains a significant challenge owing to the wide range of possible environmental conditions and NH3 concentration. In this regard, it is imperative to ensure the quality control of techniques to measure the NH3 emission levels reliably. A present study was conducted to compare the five analytical methods for the measurement of atmospheric NH3 via validation tests under laboratory and field conditions. The analytical instruments applied in the present study were based on wet chemistry, gas detection tube, electrochemical sensor, photoacoustic spectroscopy, and cavity ring-down spectroscopy. The reproducibility and linearity of all the analyzed methods were observed to be high with the relative standard deviation and coefficient of determination (R2) being 10% and > 0.9, respectively. In the case of wet chemistry and high NH3 concentration, the measured NH3 results were found to be close to the actual standard gas levels. Response times of electrochemical sensor showed faster from the instruments utilized more than one year and the high NH3 concentrations. In the field tests, NH3 concentration showed higher in the manure storage tank compared with the pig-pen. In both cases, the NH3 concentration levels measured by gas detection tube were found to be quite different from that of wet chemistry. It was proposed that such differences in NH3 concentration could arise due to the inherent instrumental characteristics and the variations in air velocity during sampling/measurement. The periodic instrumental maintenance, verification, replicate analyses, and suitable consideration of environmental factors should be considered for a more reliable measurement of NH3 concentration under real field conditions.

In this study, the main odorous substances were selected for each swine facility by investigating the concentration and occurrence characteristics of odorous substances according to farm facilities. The objective was to find a solution to manage odor effectively in swine farms. Samples collected from the boundary site, manure storage, fan, and indoor the swine building were analyzed for concentration, odor activity value (OAV), and odor contribution. As a result, there was a difference in the concentration of odorous substances as well as the tendency of OAV in each swine facility. Also, the main substances of odor in the farms were similar, but odor contribution differed from facility to facility. Therefore, it is considered that the odor management efficiency will be improved only if the proper odor reduction method is applied according to the types of main odorous substances in swine facilities.

The characteristics of ammonia during the growing period of pigs in a facility with a mechanical ventilation system were analyzed, and the emission factor was calculated. Real-time ammonia concentration was measured using photoacoustic spectroscopy equipment, and a ventilation measuring device was fabricated to measure the amount of air vented from an exhaust fan according to the operation rate. All data were collected as one-hour averages. The mean ammonia concentration, indoor temperature, and ventilation rate was 1.44~2.08 ppm, 25.5~26.4oC, and 24~32 m3/h per pig, respectively. Both concentration and ventilation rate are important factors in terms of emission management, but correlation analysis shows that the impact of concentration is higher than that of ventilation. Using ammonia concentration and ventilation data, the ammonia emissions per pig were calculated by considering the number of pigs (0.25~1.74 g/day·pig). The final ammonia emission factor yielded a value of 0.81 g/day·pig.