Search Results (31)

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. Full article

Precision livestock farming technologies support health monitoring on farms, yet few studies have evaluated their effectiveness under field conditions using reliable gold standards. This study evaluated a commercially available technology for detecting cough sounds in pigs on a commercial farm. Audio was recorded over six days using 16 microphones across two pig barns. A total of 1110 cough sounds were labelled by an on-site observer using a cough induction methodology, and 8938 other sounds from farm recordings and open-source datasets (ESC-50, UrbanSound8K, and AudioSet) were labelled. A hybrid deep learning model combining Convolutional Neural Networks and Recurrent Neural Networks was trained and evaluated using these labels. A total of 34 audio features were extracted from 1 s segments, including validated descriptors (e.g., MFCC), unverified external features, and proprietary features. Features were evaluated through 10-fold cross-validation based on classification performance and runtime, resulting in eight final features. The final model showed high performance (recall = 98.6%, specificity = 99.7%, precision = 98.8%, accuracy = 99.6%, F1-score = 98.6%). The technology tested was shown to be efficient for monitoring cough sounds in a commercial swine production facility. It is recommended to test the technology in other environments to evaluate the effectiveness in different farm settings. Full article

The control of environmental parameters in livestock farming is essential to achieve optimal ranges of temperature and humidity. HVAC systems for this purpose are characterized by high energy demands, causing significant GHG emissions when relying on fossil fuels. The aim of this study is the development and testing of a sustainable heating system for a nursery barn hosting 2500 weaners, as well as the assessment of the effectiveness and the performance of the new system. This work involved the implementation of a renewable energy source (RES) system incorporating a borehole thermal energy storage and photovoltaic thermal collectors, integrated with a Dual-Source Heat Pump. A smart control system was installed and the collected data were processed to define the optimal settings of the integrated plant for energy production and efficiency. The performance in terms of the control of the environmental conditions of the nursery barn was assessed on the basis of the environmental parameters analyzed, with particular reference to the animal-occupied zones. The results showed that a mix of RESs can be properly defined and integrated in an automated heating system to meet the specific requirements of a swine farm, thanks to a project specifically designed to exploit the renewable resources typically available in farming environments. Full article

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. Full article

Volatile organic compounds (VOCs) play a crucial role in emission control, being one of the most important sources of odor while also serving as significant precursors to secondary organic aerosols and ozone formation. Appropriate sampling methods are essential for accurately assessing the concentration and composition of VOCs within swine barns. In this study, the effects of both passive air sampling and active air sampling on VOCs were evaluated, and the influence of storage time on the VOC stability in sampling canisters for both methods was investigated. SUMMA canisters, which are electropolished and passivated with silanization, offer excellent corrosion protection and resistance to high pressure and temperature and were used in this study. The predominant component categories prevailing within the pig house were found to be oxygenated VOCs (OVOCs) and volatile sulfur compounds (VSCs), with ethanol emerging as the most abundant component of VOCs detected. Notably, the statistical analysis results revealed no significant differences between passive and active sampling regarding the impact of storage time on substance concentration. Changes in canister pressure also did not significantly affect substance stability. The results showed that the C2–C3 compounds remained relatively stable, especially within 3 days, with recoveries above 80% within 20 days. Methyl sulfide, dimethyl disulfide, and ethanol were more stable within the first week, but their recoveries significantly dropped by day 20, with methyl sulfide and dimethyl disulfide at 62.3% and 65.3%, respectively. This study contributes to the development of a foundation for selecting appropriate VOC sampling methods in swine facilities for conducting a rational analysis of VOC samples. Full article

Agricultural workers exposed to organic dust from swine concentrated animal feeding operations (CAFOs) have increased chances of contracting chronic lung disease. Mucociliary clearance represents a first line of defense against inhaled dusts, but organic dust extracts (ODEs) from swine barns cause cilia slowing, leading to decreased bacterial clearance and increased lung inflammation. Because nutritional zinc deficiency is associated with chronic lung disease, we examined the role of zinc supplementation in ODE-mediated cilia slowing. Ciliated mouse tracheal epithelial cells were pretreated with 0–10 µg/mL ZinPro^TM for 1 h, followed by treatment with 5% ODE for 24 h. Cilia beat frequency (CBF) and protein kinase C epsilon (PKCε) activity were assayed. ODE treatment resulted in cilia slowing after 24 h, which was reversed with 0.5 and 1.0 µg/mL ZinPro pre-treatment. No zinc protection was observed at 50 ng/mL, and ciliated cells detached at high concentrations (100 µg/mL). ZinPro alone produced no changes in the baseline CBF and showed no toxicity to the cells at concentrations of up to 10 µg/mL. Pre-treatment with ZinPro inhibited ODE-stimulated PKCε activation in a dose-dependent manner. Based on ZinPro’s superior cell permeability compared to zinc salts, it may be therapeutically more effective at reversing ODE-mediated cilia slowing through a PKCε pathway. These data demonstrate that zinc supplementation may support the mucociliary transport apparatus in the protection of CAFO workers against dust-mediated chronic lung disease. Full article

The optimal indoor environment is associated with comfortable temperatures along with favorable indoor air quality. One of the air pollutants, particulate matter (PM), is potentially harmful to animals and humans. Most farms have monitoring systems to identify other hazardous gases rather than PM due to the sensor cost. In recent decades, the application of environmental monitoring systems based on Internet of Things (IoT) devices that incorporate low-cost sensors has elevated extensively. The current study develops a low-cost air quality monitoring system for swine buildings based on Raspberry Pi single-board computers along with a sensor array. The system collects data using 11 types of environmental variables along with temperature, humidity, CO₂, light, pressure, and different types of gases, namely PM₁, PM_2.5, and PM₁₀. The system is designed with a central web server that provides real-time data visualization and data availability through the Internet. It was tested in actual pig barns to ensure stability and functionality. In addition, there was a collocation test conducted by placing the system in two different pig barns to validate the sensor data. The Wilcoxon rank sum test demonstrates that there are no significant differences between the two sensor datasets, as all variables have a p-value greater than 0.05. However, except for carbon monoxide (CO), none of the variables exhibit correlation exceeding 0.5 with PM concentrations. Overall, a scalable, portable, non-complex, low-cost air quality monitoring system was successfully developed within a cost of USD 94. Full article

Modeling the windborne transmission of aerosolized pathogens is challenging. We adapted an atmospheric dispersion model named the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model to simulate the windborne dispersion of porcine reproductive and respiratory syndrome virus (PRRSv) between swine farms and incorporated the findings into an outbreak investigation. The risk was estimated semi-quantitatively based on the cumulative daily deposition of windborne particles and the distance to the closest emitting farm with an ongoing outbreak. Five years of data (2014:2018) were used to study the seasonal differences of the deposition thresholds of the airborne particles containing PRRSv and to evaluate the model in relation to risk prediction and barn air filtration. When the 14-day cumulative deposition was considered, in winter, above-threshold particle depositions would reach up to 30 km from emitting farms with 84% of them being within 10 km. Long-distance pathogen transmission was highest in winter and fall, lower in spring, and least in summer. The model successfully replicated the observed seasonality of PRRSv, where fall and winter posed a higher risk for outbreaks. Reaching the humidity and temperature thresholds tolerated by the virus in spring and summer reduced the survival and infectivity of aerosols beyond 10–20 km. Within the data limitations of voluntary participation, when wind was assumed to be the sole route of PRRSv transmission, the predictive performance of the model was fair with >0.64 AUC. Barn air filtration was associated with fewer outbreaks, particularly when exposed to high levels of viral particles. This study confirms the usefulness of the HYSPLIT model as a tool when determining seasonal effects and distances and informs the near real-time risk of windborne PRRSv transmission that can be useful in future outbreak investigations and for implementing timely control measures. Full article

Numerous technologies have been investigated for mitigating air pollutant emissions from swine barns. Among them, algal photobioreactors (PBRs) can remove and utilize air pollutants such as CO₂ and NH₃ from barn exhaust. However, a challenge to PBR operation is that it involves multiple system input parameters and output goals. A key question is then how to determine the appropriate CO₂ and NH₃ concentrations in this case. Conventional statistical methods are inadequate for handling this complex problem. Multi-criteria decision-making (MCDM) emerges as a practical methodology for comparison and can be utilized to rank different CO₂–NH₃ interactions based on their environmental and biological performance. By employing MCDM methods, producers can effectively control the ratio of CO₂ and NH₃ concentrations, enabling them to identify the optimal range of operating parameters for various housing types, ensuring efficient pollutant mitigation. In this study, a multi-criteria decision-making (MCDM) approach was employed to support operation management. Specifically, influent CO₂ and NH₃ concentrations were optimized for three scenarios (the best biological, environmental, and overall performance), using a combination of two MCDM techniques. This study is anticipated to facilitate the system analysis and optimization of algae-based phytoremediation processes. Full article

Bio-curtain (i.e., curtain) is a permeable cover equipped with a spraying system for ammonia (NH₃) control in a swine facility. Previous studies investigated the NH₃ reduction effects primarily based on concentration units. It is challenging to determine the actual efficiency because of the large amount of air discharged through the large surface of the curtain, and external wind rapidly dilutes and disperses the exhausted air. Therefore, this study investigates a technique to evaluate the NH₃ reduction effect of the curtain in terms of emission rate. We constructed a metallic cover with a single hole around the curtain to gather the air discharged through it. The NH₃ reduction effect was calculated by comparing the NH₃ emission rate that was monitored in the barn exhaust fan and at the single hole of metallic cover during the non-spray and spray treatments inside the curtain at the maximum and minimum operating rate of the barn’s exhaust fan. NH₃ emission rates declined both non-spray and spray at the minimum operation rate of the barn exhaust fan, but the reduction effect was higher in spray conditions than non-spray. Accumulating NH₃-absorbed water inside the curtain under the low ventilation of the exhaust fan caused these circumstances. Full article

The livestock industry, especially swine production, has been pressurized by vicinity complaints about odor in Korea. Therefore, a lot of effort has been undertaken regarding reducing the odor emissions from pigsties, widely carried out and the washing out manure in slurry pit by liquid-phase compost has particularly been spotlighted with outstanding performance of odor reduction. However, such a washing out manure called bio-liquor circulation system (BCS) has been controlled by a timer with designated reaction time, which cannot guarantee the system performance. This research proposes an effective real-time control technology for BCS, which circulates bio-liquor to the slurry pit of swine barns. The real-time control system was operated through accurate detection of the designated control points on the oxidation reduction potential (ORP) and pH time profiles for the nitrate knee point (NKP) and nitrogen break point (NBP) in anoxic and aerobic conditions with 100 and 99.6% performances, respectively. The duration of the anoxic and aerobic phases was also automated and noticeably lowered the concentration of nutrients in the manure in the slurry-pit, which served as a source of malodor. The real-time control strategy may be an innovative way to reduce odor and simultaneously produce liquid fertilizer, and provides a reference for the optimization of the industrial scale. Full article

The growing concern over the emergence of antimicrobial resistance (AMR) in animal production as a result of extensive and inappropriate antibiotic use has prompted many swine farmers to raise their animals without antibiotics (RWA). In this study, the impact of implementing an RWA production approach in sow barns on actual on-farm antibiotic use, the emergence of AMR, and the abundance of pathogens was investigated. Over a 13-month period, fecal and nasopharynx samples were collected at 3-month intervals from sows raised in RWA barns and sows in conventional barns using antibiotics in accordance with the new regulations (non-RWA). Whole genome sequencing (WGS) was used to determine the prevalence of AMR and the presence of pathogens in those samples. Records of all drug use from the 13-month longitudinal study indicated a significant reduction in antimicrobial usage in sows from RWA barns compared to conventional non-RWA barns. Antifolates were commonly administered to non-RWA sows, whereas β-lactams were widely used to treat sows in RWA barns. Metagenomic analyses demonstrated an increased abundance of pathogenic Actinobacteria, Firmicutes, and Proteobacteria in the nasopharynx microbiome of RWA sows relative to non-RWA sows. However, WGS analyses revealed that the nasal microbiome of sows raised under RWA production exhibited a significant increase in the frequency of resistance genes coding for β-lactams, MDR, and tetracycline. Full article

Particulate matter (PM) represents an air quality management challenge for confined swine production systems. Due to the limited space and ventilation rate, PM can reach relatively high concentrations in swine barns. PM in swine barns possesses different physical, chemical, and biological characteristics than that in the atmosphere and other indoor environments. As a result, it exerts different environmental and health effects and creates some unique challenges regarding PM measurement and mitigation. Numerous research efforts have been made, generating massive data and information. However, relevant review reports are sporadic. This study aims to provide an updated comprehensive review of swine barn PM, focusing on publications since 1990. It covers various topics including PM characteristics, sources, measurement methods, and in-barn mitigation technologies. As PM in swine barns is primarily of biological origins, bioaerosols are reviewed in great detail. Relevant topics include bacterial/fungal counts, viruses, microbial community composition, antibiotic-resistant bacteria, antibiotic resistance genes, endotoxins, and (1→3)-β-D-glucans. For each topic, existing knowledge is summarized and discussed and knowledge gaps are identified. Overall, PM in swine barns is complicated in chemical and biological composition and highly variable in mass concentrations, size, and microbial abundance. Feed, feces, and skins constitute the major PM sources. Regarding in-barn PM mitigation, four technologies (oil/water sprinkling, ionization, alternation of feed and feeders, and recirculating air filtration) are dominant. However, none of them have been widely used in commercial barns. A collective discussion of major knowledge gaps and future research needs is offered at the end of the report. Full article

For its small square footage, a vertical bed biofilter was developed for odor emission mitigation for livestock facilities with limited area available for biofilter installation. However, a concern about the design is that airflow and moisture may be poorly distributed across the biofilter due to the effects of gravity. Relevant data are sporadic in the literature. To fill the knowledge gap, two vertical bed biofilters were constructed at a university swine facility and monitored for two months. The monitoring was taken at 27 grid points on each biofilter per field visit. Results revealed that both the airflow and medium moisture content were unevenly distributed. The sun-facing side of the biofilters had significantly lower medium moisture content (p < 0.01) due to solar-induced water evaporation. The side directly facing the barn exhaust had the highest airflow. Airflows varied along the height of the biofilters, but no significant difference was noted. The uniformity of airflow and moisture content, characterized by coefficient of variance (CV) and distribution uniformity (DU) respectively, were examined over the monitoring campaign. Possible reasons for uneven distribution were explored and recommendations are made to address the uniformity issue. The findings from the study are expected to further the development and implementation of biofiltration technology for livestock odor control. Full article

Supplementing fossil fuels with solar air tempering for brooding young livestock could reduce energy use and improve indoor air quality. Metal transpired solar collectors (TSC) are effective but too expensive for heating livestock buildings. An inexpensive 12.7 m² dark grey landscape-fabric-based transpired solar collector (fTSC) was evaluated in a swine nursery with two herds of pigs. A fraction of the fTSC area was underlain with phase change material (PCM) to store excess heat. The Test room with the fTSC was compared with an adjacent identical Control room, each with 120 piglets. The fTSC provided supplemental heating, e.g., with a suction velocity (V_s) of 0.027 m/s during a 9 h period, air temperature was increased by 11.6 °C (mean irradiance of 592 W/m²). Between 4 pm and 9 pm that same day, the PCM increased air temperature by 3.9 °C. The fTSC did not reduce propane use or improve pig performance. Higher V_s, operational changes and controller modifications could improve system performance and reduce cost. Modeling could be used to optimize PCM use. Hence, this very low-cost fabric-based solar air heater offers potential for considerable reduction in heat energy use in livestock barns. Full article