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The effectiveness of zinc oxide (ZnO) nanoparticles as filtering media for controlling the levels of hydrogen sulfide (H2S), ammonia (NH3), and odor in swine facilities was evaluated in this study. Semi-pilot scale tests were done to determine basic operational factors, the results of which showed that the fluidized bed air filtration system (FBAFS), loaded with ZnO nanoparticles at a rate of 0.28 g cm-2 of filter area, and a gas flow rate equivalent to 0.5 m s-1 face velocity achieved significant reduction in target gas levels. The performance of this filter system was further investigated in a roomscale environmental chamber representative of normal swine production conditions. When installed as part of the ventilation air recirculation system of the room, the FBAFS with ZnO nanoparticles achieved about 65% H2S and 42% NH3 reductions in the human-occupied zones but had no significant impact on pig performance as well as odor levels in the chamber. [ABSTRACT FROM AUTHOR]

Animal drinking and barn cleaning are activities in swine barns where potential water saving can be achieved. In this study, selected water conservation strategies involving animal drinking and barn cleaning were assessed for their effectiveness in reducing the overall water use. For animal drinking, three types of drinkers were investigated: nipple (Control), nipple with side panel, and a trough with side panel and constant water level. The drinkers were distributed randomly among pens in a pig room and their impact on water use, water wastage, and pig performance were assessed throughout one complete grow-finish cycle. Results showed that relative to conventional nipple drinkers, the use of a drinking trough with side panel and constant water level saved about 60% of water through reduced water wastage without adversely affecting pig performance throughout the growth cycle. Water wastage and water disappearance rates increased as pigs reach market weights. For cleaning, on the other hand, experiments evaluating the effect of the use of water sprinkling (pre-soaking) and different high-pressure washing nozzles on water and time consumption in pig rooms with fully slatted flooring and partially slatted flooring revealed that the use of the conventional rotating turbo nozzle led to lesser time and water consumption during high-pressure washing. Also, high-pressure washing in rooms with fully slatted flooring can be done without prior water sprinkling. Economic analysis of the different measures showed that compared to current conventional practices, the combination of using a drinking trough with side panel and constant water level for animal drinking and pre-soaking and high-pressure washing with conventional nozzle for cleaning had the greatest potential for cost savings of up to C$4.77 per pig arising from reduced overall water use and accumulated manure slurry. [ABSTRACT FROM AUTHOR]

The effectiveness of a manure scraper system for reducing the risk of barn worker and animal exposure to hydrogen sulfide (H2S) was evaluated by comparing gas levels in two swine production rooms, one with a manure scraper system installed (scraper) and the other with a conventional manure pit-plug system (control). Measurements were done over four production cycles; during each 12-week cycle, gas concentrations were measured 4 to 5 times during weeks that conventional manure removal activities were performed in the control room, while the scraper system was operated daily in the scraper room. Daily removal of manure from the scraper room resulted in measured maximum H2S concentrations that were significantly lower (by 90%) compared to the control room. The type of manure removal system had no significant effect on ammonia (NH3) concentration and emission; during each trial, NH3 emission increased in both rooms over the 4 to 5 monitored weeks. The scraper system was also operated in two different modes. These tests revealed that NH3 production was reduced when all the manure was removed from the room compared to leaving the liquid portion on the pit floor surface, although the differences were not significant (p > 0.10). The estimated cost of including the scraper system in the construction and operation of a new barn is CDN$1.89 per pig sold, which is 35% less (on a per pig basis) than the cost of retrofitting an existing facility. The manure removal system tested was effective in reducing exposure of workers and animals to H2S, without significant adverse impact on NH3 production. However, given the highly variable nature of H2S production and dispersion within a room, care should always be taken when handling manure inside swine barns. [ABSTRACT FROM AUTHOR]

A laboratory apparatus was developed for measuring the dust-emission potential of cattle feedlot surfaces as affected by manure surface characteristics. A feedlot surface was simulated with a layer of dry, loose, sieved feedlot manure, either with or without a compacted soil layer underneath. The vertical action of the cattle hoof was reproduced by dropping a steel weight onto the manure surface. High-volume samplers for PM10 (particulate matter smaller than 10 µm aerodynamic equivalent diameter) were used to collect suspended PM10. The effects of kinetic energy of the falling weight, manure depth, manure moisture content, bulk density, and surface amendment (sawdust, wheat straw, and surface water application) were investigated. For each manure depth, PM10 emission was directly related to the kinetic energy of the falling weight. For each weight drop, PM10 emission did not differ significantly with manure depth. In addition, PM10 emission was inversely related to the manure moisture content. Compaction of the manure surface reduced PM10 emission. Increased amounts of water, sawdust, or wheat straw to the manure surface also significantly decreased PM10 emission in initial tests, but dislodging/displacement of wheat straw and penetration of the wetted surface crust by the falling weight increased the emission potential for subsequent tests. The weight drop test chamber developed is a simple and repeatable method that can be used to compare relative effectiveness of different dust abatement measures. While the measurements are reproducible, the vertical action of the cattle hoof is highly simplified; thus, the WDTC might not fully reproduce the actual vertical action of the cattle hoof on a feedlot surface. In addition, the resulting aerosol may not have similar physical characteristics as those of dust emitted from feedlots. [ABSTRACT FROM AUTHOR]

Using air dispersion models to predict downwind livestock odor concentrations in order to establish science-based setback distances has the potential to become a common practice for regulatory agencies. In this study, four air dispersion models, ISCST3, AUSPLUME, INPUFF2, and CALPUFF, were used to simulate odor dispersion from a swine farm. The sensitivity analyses were conducted to develop an understanding of how model climatic parameters affect downwind odor concentrations and travel distances. Under steady-state weather conditions, the results indicated that the odor dispersion was mainly affected by atmospheric stability, wind speed, wind direction, and air temperature. Odor transport was favored by stable atmospheric conditions, low wind speed, and high ambient temperature. The four models' predictions for odor concentrations varied greatly within I km from the source; beyond that, ISCST3 and CALPUFF gave similar results (within 17%), while A USPL UME's and INPUFF2 's predictions were much lower than those of lSCST3 by up to 45.3%. However, when hourly averaged annual meteorological data were used, CALPUFF predicted the highest odor concentrations (up to 71.4% higher than those of ISCST3), and A USPL UME's predictions were also higher than those of lSCST3, which were very different from the results obtained under steady-state weather conditions. INPUFF2's predictions were the lowest (up to 40.5% lower than those of lSCST3). When determining setback distances, it is recommended that if steady-state weather data are used, the odor concentration criterion allowed should be higher than the criterion allowed when using hourly annual or monthly weather data for the same neighboring land use. [ABSTRACT FROM AUTHOR]

Methods to control microbial contamination in confined livestock facilities are important to the health of both animals and workers. In addition, bacterial contamination is also a food safety issue. The most common disinfection technique employed in livestock facilities is the application of oxidizing agents (e.g., potassium peroxymonosulphate, chlorine, hydrogen peroxide, ozone). However, these techniques are associated with a number of limitations (e.g., toxicity, high cost, corrosiveness). Recently, engineered water nanostructures (EWNS) generated using an electrospray system was found effective in inactivating foodborne bacteria. Thus, this study investigated the efficacy of EWNS generated using a laboratory-scale electrospray system in inactivating bacteria found in poultry facilities. The effects of various operating conditions (distance between the injector and grounded electrode of the electrospray system, applied voltage, liquid pH and conductivity, liquid flow rate, and treatment time) on the efficacy were also assessed. In these various experiments, airborne bacterial samples were collected from a pullet room using tryptic soy agar plates and then exposed to EWNS under varying conditions. After treatment, the plates were incubated at 37°C prior to colony counting. Reductions in bacterial concentrations up to 1.26 logs were obtained. The results indicate that the EWNS generated by the electrospray system can be a potential chemical-free alternative to conventional disinfection methods. Future tests will focus on scaling up the system for larger scale trials., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

New Canadian regulations have required that all use of antibiotics in livestock animal production should be under veterinary prescription and oversight, while the prophylactic use and inclusion of these agents in animal feed as growth promoters are also banned. In response to this new rule, many Canadian animal producers have voluntarily implemented production practices aimed at producing animals effectively while avoiding the use of antibiotics. In the swine industry, one such program is the 'raised without antibiotics' (RWA) program. In this paper, we describe a comprehensive investigative methodology comparing the effect of the adoption of the RWA approach with non-RWA pig production operations where antibiotics may still be administered on animals as needed. Our experimental approach involves a multi-year longitudinal investigation of pig farming to determine the effects of antibiotic usage on the prevalence of antimicrobial resistance (AMR) and pathogen abundance in the context of the drug exposures recorded in the RWA versus non-RWA scenarios. Surveillance of AMR and pathogens was conducted using whole-genome sequencing (WGS) in conjunction with open source tools and data pipeline analyses, which inform on the resistome, virulome and bacterial diversity in animals and materials associated with the different types of barns. This information was combined and correlated with drug usage (types and amounts) over time, along with animal health metadata (stage of growth, reason for drug use, among others). The overarching goal was to develop a set of interconnected informatic tools and data management procedures wherein specific queries could be made and customized, to reveal statistically valid cause/effect relationships. Results demonstrating possible correlations between RWA and AMR would support the Canadian pig industry, as well as regulatory agencies in new efforts, focused on reducing overall antibiotics use and in curbing the development and spread of AMR related to animal agriculture., (© 2020 The Author(s).)

The passive flux sampling is an economic and easy way to estimate gas emissions from agriculture sources. In the last decade, specific passive flux samplers (PFSs) have been developed to estimate nitrous oxide (N 2 O) emissions from agriculture sources. Packed with silica gel and zeolite 5A, the PFSs were placed facing the emission source direction close to the ventilation shafts. For validation, air samples were taken at different sampling time during 3 days on two commercial sites. The adsorbed mass of N 2 O in PFSs was recovered by thermal desorption in the laboratory. Results indicated that the mass of N 2 O adsorbed in PFSs was from 1.5 to 5.5 μg. A specific adsorption pattern was observed for each sampling. In farm 1, the mass of N 2 O adsorbed in the PFSs presented a linear behavior as a function of sampling time, and the most determined coefficient values were higher than 0.80. In farm 2, in addition to the sampling time, the N 2 O concentration and the air flow rate presented an effect on the mass adsorbed in the PFSs. On the other hand, comparison of PFSs versus other techniques indicated that PFSs offer different advantages. However, the selectivity and capacity of the adsorbent bed used need to be improved to enhance the use of PFSs proposed as a tool to estimate N 2 O emissions. Graphical Abstract PFSs enabled N 2 O sampling that followed a linear behavior as a function of sampling time. Sampling time, [N 2 O], and air flow rate determined the mass of N 2 O collected in PFSs.

Phenol biodegradation was evaluated in batch and continuous flow microbial fuel cells (MFCs). In batch-operated MFCs, biodegradation of 100-1000 mg L -1 phenol was four to six times faster when graphite granules were used instead of rods (3.5-4.8 mg L -1  h -1 vs 0.5-0.9 mg L -1  h -1 ). Similarly maximum phenol biodegradation rates in continuous MFCs with granular and single-rod electrodes were 11.5 and 0.8 mg L -1  h -1 , respectively. This superior performance was also evident in terms of electrochemical outputs, whereby continuous flow MFCs with granular graphite electrodes achieved maximum current and power densities (3444.4 mA m -3 and 777.8 mW m -3 ) that were markedly higher than those with single-rod electrodes (37.3 mA m -3 and 0.8 mW m -3 ). Addition of neutral red enhanced the electrochemical outputs to 5714.3 mA m -3 and 1428.6 mW m -3 . Using the data generated in the continuous flow MFC, biokinetic parameters including μ m , K S , Y and K e were determined as 0.03 h -1 , 24.2 mg L -1 , 0.25 mg cell (mg phenol) -1 and 3.7 × 10 -4  h -1 , respectively. Access to detailed kinetic information generated in MFC environmental conditions is critical in the design, operation and control of large-scale treatment systems utilizing MFC technology.

Intensification of modern swine production has led to many new technologies, including needleless injectors. Although needleless injectors may increase productivity (by reducing injection time) and reduce needlestick injuries, the effect on risk for musculoskeletal disorders is not clear. This project will compare conventional needles with needleless injectors in terms of cost, productivity, injury rates, biomechanical exposures, and worker preference. Muscle activity (EMG) and hand/wrist posture will be measured on swine workers performing injection tasks with both injection methods. Video recordings during the exposure assessments will compare the duration and productivity for each injection method using time-and-motion methods. Injury claim data from up to 60 pig barns will be analyzed for needlestick and musculoskeletal injuries before/after needleless injector adoption. Workers and managers will be asked about what they like and dislike about each method and what helps and hinders successful implementation. The information above will be input into a cost-benefit model to determine the incremental effects of needleless injectors in terms of occupational health, worker preference, and the financial "bottom line" of the farm. Findings will be relevant to the swine industry and are intended to be transferable to other new technologies in animal production.

Biodegradations of Na-lactate and Na-acetate were evaluated in microbial fuel cell (MFC) type bioreactors. Increase in lactate concentration from 1,000 to 5,000 mg L(-1) enhanced the biodegradation rate from 4.6 to 23.9 mg L(-1) h(-1). Sequential batch operation of MFC enhanced the lactate biodegradation rate. With acetate, neither increase in concentration nor sequential operation had a marked effect. Maximum power and current densities in MFCs operated batch-wise with lactate and acetate were 3.30 and 2.28 mW m(-2), and 48.2 and 40.2 mA m(-2), respectively. In the MFC operated continuously, increase in lactate loading rate caused the biodegradation rate to pass through maximum value of 1,668.2 mg L(-1) h(-1) (residence time: 1.2 h). Open circuit potential, power and current densities for continuous operation were 700 mV, 8.10 mW m(-2) and 43.0 mA m(-2), respectively. Using the experimental data, kinetic models for microbial growth and biodegradation of lactate and acetate in the MFC were developed.

In this study, we tested the antimicrobial activity of three metal nanoparticles (NPs), ZnO, MgO, and CaO NPs, against Salmonella enterica serovar Enteritidis in liquid medium and on solid surfaces. Out of the three tested metal NPs, ZnO NPs exhibited the most significant antimicrobial effect both in liquid medium and when embedded on solid surfaces. Therefore, we focused on revealing the mechanisms of surface-associated ZnO biocidal activity. Using the global proteome approach, we report that a great majority (79%) of the altered proteins in biofilms formed by Salmonella enterica serovar Enteritidis were downregulated, whereas a much smaller fraction (21%) of proteins were upregulated. Intriguingly, all downregulated proteins were enzymes involved in a wide range of the central metabolic pathways, including translation; amino acid biosynthetic pathways; nucleobase, nucleoside, and nucleotide biosynthetic processes; ATP synthesis-coupled proton transport; the pentose phosphate shunt; and carboxylic acid metabolic processes, indicating that ZnO NPs exert a panmetabolic toxic effect on this prokaryotic organism. In addition to their panmetabolic toxicity, ZnO NPs induced profound changes in cell envelope morphology, imposing additional necrotic effects and triggering the envelope stress response of Salmonella serovar Enteritidis. The envelope stress response effect activated periplasmic chaperones and proteases, transenvelope complexes, and regulators, thereby facilitating protection of this prokaryotic organism against ZnO NPs., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

The effects of manure age on emission of H(2)S and required level of nitrite or molybdate to control these emissions were investigated in the present work. Molybdate mediated control of H(2)S emission was also studied in semi-pilot scale open systems, and in specifically designed chambers which simulated swine production rooms. With fresh 1-, 3- and 6-month old manures average H(2)S concentration in the headspace gas of the closed systems were 4856+/-460, 3431+/-208, 1037+/-98 ppm and non-detectable, respectively. Moreover, the level of nitrite or molybdate required to control the emission of H(2)S decreased as manure age increased. In the semi-pilot scale open system and chambers, average H(2)S concentration at the surface of agitated fresh manure were 831+/-26 and 88.4+/-5.7 ppm, respectively. Furthermore, 0.1-0.25 mM molybdate was sufficient to control the emission of H(2)S. A cost study for an average size swine operation showed that the cost of treatment with molybdate was less than 1% of the overall production cost for each market hog., (Copyright 2009 Elsevier Ltd. All rights reserved.)

The aim of this work is to better understand the responses of people that are exposed to agricultural organic dust and other factors in modern swine production. We investigated the effects of toll-like receptor 4 (TLR4) genotype and gender on respiratory responses of naïve volunteers (18-28 years) to swine barn exposure. Non-smoking healthy subjects (16 men and 13 women) with TLR4 299 (Asp299Gly) and/or 399 (Thr399Ile) polymorphisms (TLR4 299/399) and age-sex matched subjects with TLR4 wild-type alleles spent 5 h in a nonexposed environment (baseline day) and 5 h in a swine facility (exposure day). The results showed significant decreases between baseline and exposure days in across-shift forced vital capacity (FVC), forced expiratory volume in 1 second (FEV(1)), forced midexpiratory flow rate (FEF(25-75)), and FEV(1)/FVC ratio and in methacholine concentration that reduced FEV1 by 20% (PC(20)) in all groups; however, there were no differences by sex or genotype. Similarly, nasal cytokines, serum cytokines, and blood neutrophil count increased after exposure; in contrast, however, these were influenced by gender. The increase in serum tumor necrosis factor-alpha (TNF-alpha) between baseline and exposure was gender-dependent with male sex associated with a significant increase in the wild-type group and female sex associated with a significant increase in the polymorphic group. These results suggest that for persons exposed to a swine facility, one's immunological response varies with gender as well as TLR4 genotype.

The objective of this study was to obtain diurnal variation profiles of odor and gas (ammonia [NH3], hydrogen sulfide [H2S], carbon dioxide [CO2]) concentrations and emission rate (OGCER) from confined swine grower/ finisher rooms under three typical weather conditions (warm, mild, and cold weather) in a year. Two grower/ finisher rooms, one with a fully slatted floor and the other with partially slatted floors, were measured for 2 consecutive days under each weather condition. The results revealed that the diurnal OGCER in the room with a fully slatted floor was 9.2-39.4% higher than that with a partially slatted floor; however, no significant differences in the diurnal OGCER were found between these two rooms, except for the NH3 concentrations in August, the NH3 and H2S concentrations and emissions in October, and odor concentrations and emissions in February (p > 0.05). The OGCER variations presented different diurnal patterns as affected by time of day, season, type of floor, ventilation rate, animal growth cycles, in-house manure storage, and weather conditions. Significant diurnal fluctuations in the OGCER (except for the odor concentrations and H2S emissions) were observed in August (p < 0.05); all of the gas emissions in October and the CO2 concentrations and emissions in February also showed significant diurnal variations (p < 0.05). These significant diurnal variations indicated that the OGCER during different periods of a day should be monitored when quantifying OGCER concentrations and emissions; for example, source emission data used in air dispersion modeling to decrease the great incertitude of setback determination using randomly measured data.

Biogenic production of hydrogen sulphide (H2S) in oil reservoirs (souring) has been shown to be controlled effectively using nitrite and molybdate salts. In the present work the effects of addition of nitrite and molybdate on reducing the emission of H2S from swine manure slurry was investigated in the laboratory and semi-pilot scale systems. Addition of 80 mM nitrite or 2 mM molybdate (final concentration in the manure slurry) to fresh manure in the laboratory scale closed systems (125 mL and 4 L) reduced the concentration of H2S in the headspace gas from 1500 microL L(-1) to 10 microL L(-1) which maintained during the remaining period of trials (40-60 days). With aged manure, similar results were achieved with a lower level of nitrite (10 mM). Simultaneous or sequential additions of nitrite and molybdate to fresh manure had similar effects. Contrary to the systems simulating biological conditions in oil reservoirs in which simultaneous addition of nitrite and molybdate has been reported to have a synergistic effect, no synergism was observed when nitrite and molybdate were added to the manure simultaneously. Experiments with fresh manure slurry in the semi-pilot scale systems (200 L) confirmed the effectiveness of this approach in which addition of 80 mM nitrite or 2 mM molybdate or a combination of 80 mM nitrite and 2 mM molybdate decreased the concentration of the H2S in the headspace gas from an initial value of 500 microL L(-1) to a low level in the range 2-25 microL L(-1) and maintained these low levels during the remaining period of trials (16 days). The concentration of ammonia (NH3) in the headspace gas of the treated systems was similar to that observed in the control system (untreated), indicating that the treatment did not have an effect on the level of present NH3. Although the addition of nitrite or molybdate reduced emissions of H2S from swine manure and the associated health and safety concerns, it had little impact on the intensity of odour in the headspace gas samples from the semi-pilot scale system.