Accurate estimates of daily manure production per animal are essential for designing livestock facilities and developing environmental policies. This study assessed manure production in bedded pack barns, a common type of beef cattle housing in Korea, where excreted manure is mixed with bedding and composted before removal. Because composting alters manure mass through moisture evaporation and organic matter decomposition, manure production was evaluated by season (summer, autumn, winter) and cattle growth stage (growing calf, steer, cow). A reliable baseline was established by directly measuring raw manure excretion in a pen for 12 days under controlled conditions (average temperature of -3.9°C and a wind speed of 0.1 m/s), under which moisture evaporation and organic matter decomposition were negligible. Average manure production varied by growth stage: 11.8 ± 2.9 kg/head/day for growing calf, 11.2 ± 2.7 kg/head/day for steer, and 15.8 ± 4.7 kg/head/day for cow. Manure production showed a significant correlation with feed intake (R2 = 0.69), which partially explained the variation across growth stages; however, composting processes influenced by seasonal factors also played important roles. Compared to the baseline, moisture mass decreased by 50%-55% in summer, 12%-22% in autumn, and 6%-21% in winter. Volatile solids decomposition ranged seasonally from 37% to 48% in summer to 9% to 14% in winter, with autumn values between 22% and 28%. Consequently, total manure production declined by approximately 51% in summer and 18% in winter relative to the baseline. These findings underscore the importance of considering seasonal effects, growth stages, and composting practices when estimating manure production in bedded pack barns.

Greenhouse gas (GHG) emissions are an unavoidable issue during manure composting. While soybean peroxidase (SBP), a low-value by-product of soybean processing, has been widely studied for odor mitigation, its potential to mitigate GHG emissions during composting remains poorly understood. To address this knowledge gap, this study investigated the effects of two SBP application strategies, single and split addition, on GHG emission reduction. The results indicate that SBP application helps prevent nitrogen loss and reduces CO2 emissions by 12–14%, CH4 emissions by 5–8%, and N2O emissions by 30–49%. As CO2 is a biogenic product, total GHGs calculated from CH4 and N2O are reduced by 26-39%. Microbial analysis emphasized the roles of nitrifying and denitrifying bacteria in influencing N2O emissions. Furthermore, ROS-related bacteria were observed, which likely influence the overall reduction in GHGs. Correlation heatmaps revealed relationships between environmental parameters and GHG emissions, highlighting the complexity and dynamics of the composting process. This study demonstrates that a single SBP addition is more effective than a split addition in mitigating GHG emissions, which may be due to the higher SBP addition on the initial day, leading to more stable and sustained chemical oxidation effects. Overall, this study suggests the potential of peroxidase-based additives, also present in other food by-products, as bio-based solutions for reducing GHG emissions.

A simplified multi-chamber manure (mixture of feces and urine) incubation system was developed to accurately measure ammonia (NH3) and hydrogen sulfide (H2S) emissions from manure. Addressing the complexity of conventional equipment, this methodological innovation replaces individual mass flow controllers and real-time gas analyzers with a practical 24-hour composite sampling approach. The system comprises six chambers with controlled airflow (2 L/minute) and humidity, directing vented air into Tedlar bags for reliable daily quantification. Accuracy was evaluated by introducing a known concentration of NH3 (92 ppm) into empty chambers, resulting in a mean recovery rate of 95.7% with no significant differences among chambers. Precision was assessed by incubating identical manure samples in all chambers over five days, demonstrating consistent NH3 emission rates (coefficient of variation: 2.6%). As an application example, the validated system was used to evaluate the effects of dietary crude protein (CP) levels on NH3 and H2S emissions from manure of Hanwoo steers during a 10-day incubation. The system successfully captured emission dynamics, clearly detecting that a high-CP diet significantly increased daily NH3 emission rates (P < 0.001) compared to lower-CP diets, while confirming that cumulative NH3 and H2S emissions remained unaffected by the dietary CP levels. Ultimately, this costeffective and standardized system bridges the gap between complex laboratory instrumentation and practical nutritional research, providing a robust platform for evaluating dietary strategies aimed at mitigating livestock odor emissions.

The temporal dynamics of nitrogen (N) fractions and ammonia (NH3) volatilization were investigated over a 56-day storage period using a laboratory-scale pig slurry pit simulator. A detailed N mass balance, encompassing total N (TN), total ammonium N (TAN), organic N, and nitrate N (NO3−-N) fractions, yielded a N mass recovery of 96.5%, despite uncertainties associated with discrete emission measurements, with a TN reduction of 28.3 g vessel−1 closely matched by cumulative NH3-N emissions of 27.3 g. The NH3 emission profile exhibited a distinct two-phase pattern. During Phase I (days 1–28), emissions remained stable at 16.7–19.5 g m−2 d−1, accounting for approximately 58% of total cumulative NH3-N loss (518.6 g m−2), consistent with zero-order kinetics. Phase II (days 29–56) was characterized by first-order exponential decay (k = 0.0293 d−1, R2 = 0.982), coinciding with progressive TAN depletion. Measured emission rates were strongly correlated with theoretical free ammonia N (FAN) concentrations derived from pH and temperature (R2 = 0.74), confirming that theoretical FAN provides a useful upper bound for emission potential, although the actual gaseous flux is restricted by mass-transfer limitations at the slurry–air interface. These results demonstrate that continuous pH and temperature monitoring provides a practical basis for tracking emission dynamics and informing the timing of mitigation interventions, particularly during the high-flux initial storage phase.

This study evaluated the impact of a ground channel ventilation system on seasonal ammonia emissions in a swine-finishing barn over three distinct seasons: summer, late autumn, and winter. The ground channel system tempered inlet air, cooling it during summer and warming it during colder seasons, maintaining stable room temperatures despite external fluctuations. During summer, the ground channel reduced the incoming air temperature from 26.9 °C to 22.5 °C, contributing to steady barn temperatures (28.0 °C) and mitigating ammonia emissions, which reached 111.0 ± 23.6 g day−1 AU−1. In late autumn and winter, it warmed the inlet air from 4.7 °C and −0.7 °C to 8.1 °C and 6.8 °C, respectively, maintaining stable room temperatures (25.1 °C and 24.3 °C). Ammonia emissions remained consistent across seasons, with 125.0 ± 37.3 g day−1 AU−1 in late autumn and 107.1 ± 20.5 g day−1 AU−1 in winter. Thus, ammonia emissions showed no seasonal differences, highlighting the system’s effectiveness in balancing ventilation rates with emissions. During late autumn and winter, it improved air quality without compromising thermal comfort for the swine. In summer, the reduced ventilation demand lowered ammonia emissions, supporting the effective management of ammonia emissions year-round. Future research should investigate the system’s effects on other gases and slurry pit temperatures.

Microbial inoculation is a commonly applied approach in composting to enhance organic matter biodegradation and reduce odor emissions. However, the different characteristics of bacteria in terms of temperature can be considered to optimize their effect during different phases of composting. A mesophilic bacterium, namely Aquamicrobium lusatiense NLF 2-7, was evaluated to mitigate odor emissions and enhance the bacterial community under mesophilic composting. Two different treatments were designed: treatment 1 with a single inoculation on the initial day and treatment 2 with split inoculation at the initial and after 2 weeks. Results show that the treatments improve organic matter decomposition by 17.7-28.6% and significantly reduce volatile sulfur compound emissions, especially dimethyl sulfide (DMS) and hydrogen sulfide (H2S) during the initial phase of composting. DMS emissions were mostly emitted in the first week, with reduction rates of 60.3% and 61.5% in both treatments, respectively. Additionally, mean phenol emissions were reduced by 7.9% in treatment 1 and 11.7% in treatment 2. The dominant bacterial phyla during composting were Bacillota, Pseudomonadota, Bacteroidota, and Actinomycetota, comprising 74 to 95% of the total population. This experiment suggests that A. lusatiense NLF 2-7, which is known for reducing sulfur emissions, can also enhance organic matter decomposition. Split inoculation appears more beneficial, with an initial inoculation managing sulfur emissions early on, followed by a second inoculation after the thermophilic phase to control phenol emissions throughout the composting process.

This study evaluated the odor mitigation potential of rice husk biochar in a simulated dairy bedded pack over 21 days. Biochar was incorporated into a dairy manure–sawdust mixture at 5% and 10% dry weight. Emissions of key odorous compounds—ammonia (NH3), sulfur compounds, volatile fatty acids, phenol, p-cresol, and indole—were evaluated. Odor units were assessed to determine perceived odor reduction. Biochar significantly reduced NH3 and dimethyl sulfide (DMS) emissions: NH3 by 27% and 43%, and DMS by 53% and 75%, at 5% and 10% application, respectively. The NH3 reduction was attributed to ammoniacal nitrogen adsorption, while the DMS reduction likely resulted from enhanced air permeability suppressing anaerobic bacterial activity. The 5% biochar treatment, achieving 63% and 70% of the NH3 and DMS reductions attained by the 10% treatment, respectively, offers a more practical and cost-effective option. Other odorous compounds were not significantly affected. A temporary reduction in odor units was observed on day 7. Rice husk biochar contains 14.5% atomic Si, primarily as silica, which supports structural stability but hinders pore development, reducing adsorption efficiency. These findings demonstrate the importance of biochar’s physicochemical properties in odor mitigation. Future research should evaluate long-term field performance, microbial interactions, and silica modification strategies.

Windrow composting is an effective treatment method for livestock manure. However, few studies have investigated the detailed relationship between the composting process and surface water quality impacts on surrounding areas. This study conducted a compost nutrient balance analysis (CNBA) of composting materials under natural field conditions using livestock manure samples collected at a research windrow composting site in central Iowa, USA. The research site included a fly ash composting pad surface and vegetative filter strip (VFS) buffer plots. Surface runoff and pollutant transport data that included sediment (solids), nitrogen (N), and phosphorus (P) nutrient concentrations and losses also were collected and analyzed. The CNBA results indicated that all composting properties and materials mostly followed the general compost biodegradation-related trends throughout spring (early) and summer (late) 60-day composting periods. However, the results also showed that while an average of 34% P was lost due to the composting process, only an average of 0.3% P was lost to runoff from the no-VFS buffer (control) plots during the composting periods. Published research indicates significantly lower P losses from control plot runoff may be attributed to the chemical and physical conversion effects of the P-sorbent fly ash pad surface material. Consequently, further research should be conducted that considers the use of fly ash or other P-sorbent pad surface materials in the construction of new windrow composting sites and the upgrading of existing composting facilities.

This study investigated the effectiveness of floating covers (FCs) in mitigating ammonia (NH3) and hydrogen sulfide (H2S) emissions from lab-scale swine slurry pits. Lab experiments were conducted over 125 days, comparing a treatment setup with FCs covering approximately 51.6% of the slurry surface to a control setup without covers. The results showed a significant reduction in NH3 emissions by 54.4% with FCs (p < 0.05), which was attributed to their ability to limit NH3 volatilization and promote crust formation. Although H2S emissions were also reduced by 22.7%, this decrease was not statistically significant, likely due to the complex factors influencing H2S production. These findings highlight the role of floating covers (FCs) in improving air quality within swine barns and reducing environmental pollution. By minimizing nitrogen loss as ammonia (NH3), FCs enhance nitrogen recycling into agricultural land, supporting sustainable nutrient management. This aligns with broader sustainability goals by addressing air quality concerns, reducing odors, and improving resource efficiency in livestock systems. This study offers an effective method to mitigate air pollution, providing a foundation for practical and sustainable agricultural practices.

Polyvinyl fluoride (PVF) film bags are widely used for the temporary storage of air samples prior to analysis due to their durability, toughness, and chemical inertness to a broad range of compounds. However, factors such as temperature and storage time can significantly affect the performance of PVF film bags, with important implications for the accuracy of sample analysis. This study evaluated the stability of syngas in Tedlar (R) PVF film bags under varying storage temperatures (-20 degrees C, 25 degrees C, and 38 degrees C) and durations (0-168 h), with Pearson correlation analysis conducted to assess the impact of these conditions. The results revealed that both storage temperature and time notably influence syngas stability, particularly for hydrogen and carbon dioxide. A strong negative correlation was observed between the concentrations of these gases and temperature, with the most pronounced negative correlations at 38 degrees C, showing coefficients of -0.974 and -0.977 for hydrogen and carbon dioxide, respectively. At 25 degrees C and 38 degrees C, hydrogen and carbon dioxide exhibited significant concentration losses, with recovery rates of 81.2 f 4.5% and 66.9 f 1.2% for hydrogen, and 90.9 f 1.1% and 89.3 f 1.5% for carbon dioxide, respectively. In contrast, gases stored at -20 degrees C for seven days maintained recovery rates exceeding 95%. This study identifies low-temperature storage in PVF film sampling bags as an effective method for preserving syngas integrity ensuring data accuracy for informed syngas utilization and application decisions.

The present study investigated the impact of peat moss as a feed additive on the emission of methane (CH4) and carbon dioxide (CO2) from piggery slurry stored in slurry pits. There is no well-known study on the relationship between pig manure generated after feeding peat moss as a feed additive and CH4 and CO2 released during the storage period. A lab-scale experiment was conducted for two months using a slurry pit simulator composed of six vessels-three for pig slurry collected after feeding 3.0% peat moss as a feed additive (PFS) and three for pig slurry without feeding peat moss (CTL). PFS reduced CO2 and CH4 emissions (p < 0.05) from stored pig slurry by approximately 23% and 44%, respectively. PFS exhibits substantially elevated concentrations of humic substance (HS) such as humic acid, fulvic acid, and humin compared with CTL, with fold differences of 2.3, 1.8, and 1.1, respectively. Elevated HS levels in the PFS seemed to limit hydrolysis, resulting in lower total volatile fatty acid concentrations compared with CTL. A dominance of CH4 in total carbon emissions was observed (p < 0.05), with CH4 accounting for approximately 93% and 95% of total carbon emissions in PFS and CTL, respectively. PFS had a roughly 43% lower impact on cumulative carbon emissions than CTL, primarily due to decreased CH4 emissions. These findings suggest that PFS may be a promising approach for mitigating carbon emissions and potentially impacting environmental sustainability and climate change mitigation efforts.

This study evaluated the efficacy of filter adsorption-based odor control facilities, which are being used in other industries, for their applicability in livestock farms. The filter adsorption-based odor control facility installed in a pig farm was evaluated for 74 days, monitoring three points: the inlet section, outlet section, and hallway, using a real-time odor monitoring system. The study results showed that the average concentrations of NH3 in the inlet, outlet, and hallway were 10.4 ± 9.6 ppm, 7.3 ± 4.1 ppm, and 2.7 ± 3.8 ppm, respectively. The H2S concentrations in the inlet and outlet sections were 84.9.4 ± 76.1 ppb and 12.3 ± 11.9 ppb, respectively, indicating a significant reduction in concentrations after passing through the filter adsorption-based odor control facility. The H2S concentration in the hallway was measured at 13.3 ± 23.8 ppb. The removal efficiency of NH3 and H2S by the filter adsorption-based odor control facility was approximately 13.5% and 66%, respectively, showing better effectiveness in removing H2S than NH3. However, regular filter replacement and maintenance are necessary to maintain efficient odor removal and odor control efficiency in the evaluated filter adsorption-based odor control facility. The frequency of filter maintenance and replacement may vary depending on the odor levels of the specific facility. According to the research findings, it is recommended to replace the filters approximately every 40-50 days for facilities with NH3 concentrations of around 10 ppm and every 3 to 6 months for facilities with H2S concentrations around 85 ppb.

Inoculation is a widely used method to improve the efficiency of anaerobic digestion (AD) with a high organic load. This study was conducted to prove the potential of dairy manure as an inoculum source for AD of swine manure. Furthermore, an appropriate inoculum-to-substrate (I/S) ratio was determined to improve methane yield and reduce the required time of AD. We carried out 176 days of anaerobic digestion for five different I/S ratios (3, 1, and 0.3 on a volatile solid basis, dairy manure alone, and swine manure alone) of manure, using solid container submerged lab-scale reactors in mesophilic conditions. As a result, solid-state swine manure inoculated with dairy manure could be digested without inhibition caused by ammonia and volatile fatty acid accumulation. The highest methane yield potential was observed in I/S ratios 1 and 0.3, as 133 and 145 mL CH4·g−1-VS, respectively. The lag phase of swine manure alone was more extended, 41 to 47 days, than other treatments containing dairy manure, directly related to tardy startup. These results revealed that dairy manure can be used as an inoculum source for AD of swine manure. The proper I/S ratios leading to successful AD of swine manure were 1 and 0.3.

This study aimed to explore solutions for odor-related conflicts using a mobile odor alert application, and to collect information on the location, date, frequency, and intensity of odor to analyze the degree of odor perceived by local residents. Of the 861 evaluations conducted, 89% of the odor alerts were rated as ‘odorless’, ‘slight’, or ‘moderate’, and in the facility-based analysis, pig farms, factories, cattle farms, and other livestock farms showed a high frequency of ‘strong’ or worse odor. However, in areas where complaints were expected, such as villages, downtown areas/schools/parks, it was found that despite the presence of odor-causing facilities within 2 km, the impact of odor was low. The data collected through the application developed by the research team is useful for citizen-participatory odor environmental monitoring and is expected to be used for policy making and environmental improvement by local governments. These results are expected to contribute to sustainable environmental improvement and the promotion of community health.