Swine heat production (HP) data are an essential element of numerous aspects affecting swine production sustainability, such as, housing environmental control design, energetics and thermoregulation modeling, as well as understanding of feed energy partitioning. Accurate HP values that reflect the continuous advances in growth, nutrition, health, and reproduction are needed to update outdated models and data; hence, this review of swine HP values is a critical contribution. This review updates the last previous review conducted in 2004, by reviewing literature from growing and breeding pigs from 2003 to 2020. In total, 33 references were identified that provided relevant HP data and from these references, 192 records were identified for pigs ranging in weight from 12.5 to 283 kg and exposed to temperatures between 12.0°C and 35.5°C. For growing pigs at thermoneutral conditions, a 4.7% average increase in HP was observed compared to HP data summarized from 1988 to 2004. Only five records were identified for gestating sows and the 43 records for lactating sows plus litter. This sow data shows high variability and inconsistent trends with temperature, most likely attributed to variation in experimental protocols, management, and limited reported information. There is still a lack of data on growing pigs greater than 105 kg, gilts and gestating sows housed in different systems (stall, pen, mixed, etc.), and latent HP values that reflect different housing systems. Further, there is a need to standardize reporting of HP values (with an example provided) across different disciplines to drive documentation of increased swine production efficiency, environmental control design, and energetics modeling.

HighlightsDesign and construction of mobile swine facility on a flat decked trailer for experimentation.Air infiltration evaluation for an experimental building.Theoretical building shell thermal analysis and heat transfer determination.Abstract. Specialized animal environment experiments needing swine facilities calls for novel technology creation to enable unique experimentation without the drawbacks of traditional swine facilities. In a full-scale swine facility, there are challenges with cost, increased travel time to sites, additional labor is required, the facility cannot be fully controlled, and biosecurity becomes a risk. A small-scale, mobile swine confinement laboratory was designed and built to mitigate the challenges faced in a full-scale barn. The mobility of the laboratory enables it to travel to swine farms to obtain fresh animal specimens, which allows the experiments and data collected to be more representative of an in-barn application. The model facility, built on a flat-bed trailer, has two identical, fully instrumented rooms (L × W × H) of 2.24 × 2.29 × 2.05 m (88.0 × 90.0 × 80.5 in.) with a 0.46 m (18 in.) shallow pit, replicating typical swine finishing rooms. Walls were composed of typical wood-frame construction with interior paneling and metal clad on the exterior. Instrumentation allows the environment and air quality of the rooms, along with other parameters, to be controlled and monitored. The rear portion of the trailer includes an instrumentation room to house necessary computers, controllers, and associated equipment. Commissioning of components and verifying function of equipment were performed, which included quantifying infiltration and performing a thermal analysis for each room. Analysis showed that the infiltration equation was distinct for each room. The use of this laboratory for qualitative and quantitative evaluation of in-barn experimentation on a controlled, small-scale will mitigate the challenges presented in a typical barn. Keywords: Building, Commissioning, Facility, Heat transfer, Mobile, Pig.

Objectives: To determine the effect of heat lamps versus heat mats on piglet performance measures, sow lying behavior, piglet behavior, and energy use. Materials and methods: Seventeen multiparous crossbred sows housed in farrowing stalls were randomly assigned to one of two heat source treatments: Baby Pig Heat Mat - Single 48 (MAT; n = 8) or Poly Heat Lamp Fixture (LAMP; n = 9). Piglets were weighed on day 1 and at weaning and any mortalities were recorded to evaluate piglet production measures. For 7 days over the course of lactation (day 1, 2, 3, 4, 5, week before weaning, and day before weaning), sows and their litters were observed for 2 hours twice daily to evaluate behavior. Electric meters were attached to individual heat source units to monitor energy use. Results: Piglet production parameters were unaffected by treatment type; litter weaning weight (P = .85), litter average daily gain (P = .79), and preweaning mortality (P = .58). Piglet behavior had variation in the number of piglets using a heat source within day across treatments (P < .001). The number of piglets in contact with the sow decreased during early lactation for both treatment types and increased during late lactation with more MAT pigs tending to be in contact with the sow (P < .001). Implications: Using heat mats as supplemental heat in the farrowing house may result in decreased energy use and increased savings without hindering piglet production parameters.

Ventilation air filtration is becoming a popular method to control airborne transmission of diseases on commercial sow farms. For example, air filtration can reduce the frequency of airborne outbreaks of porcine reproductive and respiratory syndrome virus (PRRSV). The capital investment is justified on the basis of diseases losses avoided, but better data on filter lifespan is needed to give producers a more complete understanding of all costs related to air filtration. In Objective 1 a 6-month (May-to-November) intensive study was done on commercial sow farms to determine factors affecting pre-filter lifespan. In Objective 2, a study into methods to prolong pre-filter life span was done under high dust loading conditions (row crop harvest season) on a gilt-development (GDU) farm. The filter brand, correct installation, and three factors related to the filter bank (north or south facing, driveway side, and what the bank faced) were collected along with filter weight and airflow using mobile air filter testing (MAFT) laboratory for random sub-sample from each filter bank on each farm in the study. For Objective 1, the filter brand and correct installation had significant impacts on lifespan. The worst case factors for filter lifespan were facing a barn exhaust, being on the driveway side of the barn and facing north. For Objective 2, the filter prolonging study found that the treatment methods improved filter lifespan and that the extreme loading scenario was significantly worse for filter lifespan than the conditions on the sow farms in this study. The various effects on pre-filter lifespan and improving estimations for filter lifespan is a key step to understanding the operating costs of air filter systems on commercial swine farms.

The US swine industry is shifting towards filtered fresh-air ventilation systems that use pleated filters to improve breeding herd health and reduce airborne disease outbreak frequency. Loaded filters reduce airflow causing a poor environment and elevated energy use. Typical axial fans cannot efficiently maintain the rated differential pressure (DP; 100 Pa) for pleated filters; hence, a lower design filter DP (37 Pa) is used and consequently, more filters are required to achieve design maximum ventilation. Large, common filter banks for multiple staged fans present significant challenges in using continuous DP measurement to assess filter life, making it impossible to separate filter loading DP from overall airflow DP. A mobile air filter testing (MAFT) laboratory is needed to provide timely farm-to-farm testing of on-site filters by accurately measuring airflow at given DPs to identify filter end-of-life and enable research on spatiotemporal filter loading characteristics. The MAFT laboratory consisted of a 4.6 m long acrylic test duct mounted in an enclosed trailer capable of operating at 37 Pa DP across primary and secondary filter combinations for 169 to 1,692 m hr airflows. Test duct calibration (R>0.99; RMSE=8.40×10 m hr) at BESS Labs and validation against an off-site third-party laboratory (34 loaded filters from commercial swine facilities) showed good agreement (p<0.0001). Relative expanded uncertainty was calculated to range from 1.5% to 5% (1,417 to 343 m hr). The MAFT laboratory provides a unique approach for testing agricultural filter performance directly on-farm to eliminate the time and cost to test filters off-site at third-party laboratories.

The US swine industry is shifting towards filtered fresh-air ventilation systems that use pleated filters to improve breeding herd health and reduce airborne disease outbreak frequency. Loaded filters reduce airflow causing a poor environment and elevated energy use. Typical axial fans cannot efficiently maintain the rated differential pressure (DP; 100 Pa) for pleated filters; hence, a lower design filter DP (37 Pa) is used and consequently, more filters are required to achieve design maximum ventilation. Large, common filter banks for multiple staged fans presents significant challenges in using continuous DP measurement to assess filter life, making it impossible to separate filter loading DP from overall airflow DP. A mobile air filter testing (MAFT) laboratory is needed to provide timely farm-to-farm testing of on-site filters by accurately measuring airflow at given DPs to identify filter end-of-life and enable research on spatiotemporal filter loading characteristics. The MAFT laboratory consisted of a 4.6 m long acrylic test duct mounted in an enclosed trailer capable of operating at 37 Pa DP across primary and secondary filter combinations for 2,820 to 28,200 L min -1 airflows. Test duct calibration (R²>0.99; RMSE=1.40×10 2 L min -1 ) at BESS Labs and validation against a third-party laboratory (34 loaded filters from commercial swine facilities) showed good agreement (p<0.0001). Relative expanded uncertainty was calculated to range from 1.5% to 5% (23,619 to 5,721 L min -1 ). The MAFT laboratory provides a unique approach for testing agricultural filter performance directly on-farm to eliminate the time and cost to test filters at third-party laboratories

Abstract Pre-weaning mortality, currently 20% in the United States, continues to rise and has been estimated to cost $400 to $600 million annually. Creep heat accounts for 36% (125 watt heat lamps) of the estimated 685,000 kWh electrical subtotal used in a 3000 sow farm. The objective of this study was to determine the effect of heat source type on production and electrical usage in the farrowing house at the Iowa State University Allen E. Christian Swine Teaching Farm. Seven multiparous crossbred sows housed in farrowing stalls were randomly assigned to a heat source treatment; Baby Pig Heat Mat – Single 48 (Kane Manufacturing, Pleasant Hill, IA; MAT n = 4) or Hog Slat® Poly Heat Lamp Fixture (Hogslat, Newton Grove, NC; LAMP n = 3). LAMP was controlled via a thermostat and varied by height and MAT was controlled via Thermostat Programmable 1 Zone (Kane Manufacturing, Pleasant Hill, IA). Both heat sources were set at 32.2⁰C and this was confirmed using an infrared temperature gun. Kill-A-Watt EZ Meter P4460 were connected to the individual heat source for group lactation duration to measure kilowatt hours (kWh) and were read twice weekly. Piglets were weighed on D1 (farrowing = D0) and at weaning. Production data including pre-weaning mortality and piglet weight at weaning were analyzed using a mixed model with parity, room and covariate of litter birth weight being fixed effects and sow being random. There was no difference in production values, pre-weaning mortality (P > 0.63,MAT=11.11%, LAMP = 11.76%) and piglet weaning weight (P > 0.13, MAT = 5.30 ± 0.18 kg, LAMP = 5.99 ± 0.21 kg), due to heat source type. The MAT (LS Mean 11.59 ± 1.31 kWh) used 4.2 times less electricity than LAMP (LS Mean 57.30 ± 1.56 kWh) (P < 0.05). In conclusion, with no difference in production values heat mats controlled with a programmable thermostat can decrease the high energy needs in the farrowing house.

Fresh air intake filtration is used on commercial swine breeding-gestation-farrowing farms to reduce the frequency of airborne infectious agents. For swine producers, porcine reproductive and respiratory syndrome virus (PRRSV), influenza A virus and Mycoplasma hyopneumoniae are considered the most economically challenging airborne pathogens. Reduced frequency of disease outbreaks has been attributed to retrofitting existing systems with filtration. Economic analysis of operating costs includes energy use, maintenance and replacement of filters. Filter replacement, the largest operational cost, is dependent on filter lifespan. However, limited data is available on filter lifespan and the rate of airflow reduction during the high dust-loading periods typically encountered for filtered swine building ventilation systems. Therefore, the objectives of this study were (1) estimate the average primary filter airflow reduction per day, (2) identify the impact of factors related to site layout, filter characteristics and weather on airflow reduction rates of filters in positive-pressure ventilated buildings and (3) determine methods for reducing average primary filter airflow reduction rate per day during row-crop harvest season. Both filter brand and the installed orientation of the filter significantly (p = 0.0314, p = 0.0419, respectively) impacted airflow reduction rates. All site layout factors were significant (driveway side, p = 0.001; dormer orientation, p = 0.0001; and dormer configuration, p = 0.0001). The materials tested significantly reduced the airflow reduction rate during row-crop harvest. The information obtained in this study will aid producers when planning for filtration, highlight details relevant to the purchase and installation of filters, identify factors that affect filter lifespan and identify methods for improving filter lifespan.

Current thermal environment (TE) monitoring and control strategies for livestock and poultry facilities require enhanced measurement capabilities to provide an optimum TE based on the animals' thermal demands. Further, techniques for combining additional parameters are needed to adequately assess the total impact of the TE on the animals. Hence, two papers introduce a spatial network of 44 Thermal Environment Sensor Arrays (TESAs), each with a custom data acquisition system (Part 1) and a technique for evaluating the TE as a function of mean body temperature difference from thermally comfortable pigs using estimated body mass and TESA measurements as inputs (Part 2). The TESAs and new thermal index were deployed in a commercial pig facility to perform a preliminary assessment of robustness and capabilities under production settings. Each TESA measured dry-bulb temperature (T-db), black globe temperature, airspeed, and relative humidity (RH), and required a custom circuit board with a microcontroller, signal conditioning, and communication hardware. After closeout (completion of the production cycle), TESAs were validated with a reference system to determine individual time constants and assess if a significant bias correction was needed (except airspeed). Total number of usable measurements for subsequent analysis for all sensors per TESA averaged (95% CI) 202,310 (199,187; 205,437). In summary, 7% T-db thermistor, 9% digital T-db, and 27% RH sensors required correction after 170 d inside the facility. Utilisation of low-cost sensors, open source software, and microcontrollers allowed this novel network to provide sufficient measurement density to promote future queries on TE data in animal facilities. (C) 2018 lAgrE. Published by Elsevier Ltd. All rights reserved.

The thermal environment (TE) inside swine buildings not only has an impact on the productivity and well-being of the animals, but the energy usage of the building as well. As the swine industry has grown and evolved to address disease pressures faced by many producers, a novel positive pressure ventilation with filtration system has been employed on relatively large footprint 3,000-head breeding-gestation barns. Such buildings present complex challenges of controlling an independent fan system based on attic static pressure alone, inlet zones on building temperature, and variable opening exhausts on building temperature and building static pressure. The objectives of this study were 1) to evaluate the Thermal Environment Modification System and Air Distribution System (TEMADS) controller response, 2) evaluate the spatial uniformity within quadrants of a barn and 3) evaluate the Temperature Humidity Index (THI) at strategic points within a building. For this study 53 combination dry-bulb temperature and relative humidity sensors and dry-bulb temperature only sensors were installed in two breeding-gestation buildings. A set-point uniformity coefficient was used to evaluate the TEMADS controller performance. The highest coefficient was seen when ambient temperature was below 0oC, and neither barn was capable of reaching the ideal uniformity coefficient of 0.80. The spatial uniformity in each barn showed a higher uniformity across the pen rows (west to east) with the highest uniformity in the pen rows closest to the fans. During an extended period of heat stress conditions, the TEMADS was unable to reduce the THI below alert levels, and once the ambient THI dropped below the alert level, the barn conditions lagged considerably. The results from this study show that the TEMADS was most successful when ambient temperature was below the set-point, as expected, and while not as capable at maintaining the set-point temperature, the temperature achieved was nearly uniform throughout the barn.

The thermal environment (TE) inside livestock and poultry facilities has a substantial impact on animal growth performance and facility energy usage; therefore, the TE must be quantified correctly to maintain the optimal TE that maximizes feed efficiency and consumes minimal resources. To achieve this goal, a TE sensor array (TESA) and accompanying data acquisition system were previously developed to measure dry-bulb temperature (t(db)), black globe temperature, airspeed, and relative humidity (RH). While measurement of each parameter is useful individually, it is more informative when they are combined to estimate and assess the total impact that the TE has on an animal. Hence, the objectives of this study were to (1) design, construct, and commission a TE simulation system, named the Animal Thermal Environment Replication and Measurement System (AThERMS), and (2) compare total sensible heat loss estimated by TESA to a reference ideal temperature source (ITS) when subjected to different TE conditions inside AThERMS. AThERMS is a 1.04 x 1.17 x 1.04 m chamber inside a large insulated enclosure in which air supplied by an air handling unit provides unique combinations of t(db), RH, and airspeed while independently controlling chamber surface temperature (t(s)). Commissioning of AThERMS included qualitative (smoke visualization) and quantitative (three-dimensional traverse) velocity characterizations in the central region of the chamber and verification of similar and stable t(s) for all six surfaces. Analysis of velocity contours at three nominal flow rates indicated steady patterns, and at three nominal t(s) values (13 degrees C, 23 degrees C, and 33 degrees C) during 2 h steady-state operation, the maximum average difference between any two of the six surface t(s) values was 0.26 degrees C. The TESA was then suspended in AThERMS adjacent to the ITS (15.24 cm diameter black copper sphere with a heater immersed in water). The ITS and TESA were subjected to two nominal airspeeds (similar to 0.5 and 2.0 m s(-1)) at three nominal tdb values (17 degrees C, 25 degrees C, and 33 degrees C) with a mean radiant temperature approximately equal to the nominal t(db). Total heat loss was estimated from heat transfer theory with TESA measurements as inputs and compared to the measured root mean square power required to maintain a constant water temperature in the ITS. Overall, predicted total heat loss underestimated measured power for all six tests. Future work needs to improve the measurement accuracy at low total heat losses. AThERMS can be used to simulate different TEs that an animal may experience and provide steady reference conditions to verify TE measurements. The TESA is a novel and effective tool for understanding the TE distribution and estimating total heat loss.

Seasonal variability attributed to heat stress (HS) has a large economic impact on the US swine industry by reducing daily gain and finishing market weights. Strategies to mitigate HS lack evidence showing effectiveness in different climates and have not been adequately controlled to provide a thermally optimum environment for pigs. Hence, the goal of this study was to describe the initial experimental design and instrumentation as well as develop innovative control algorithms for operating evaporative pads (EPs) and sprinklers. Located in northeast Iowa, a four room (~1,875 head per room) grow-finish facility featured sideby-side rooms separated by a hallway. Three thermal environment sensor arrays (TESAs) quantifying drybulb and globe temperature, relative humidity, and airspeed were placed in each room and served as feedback for control system to evaluate the thermal environment and potential HS conditions. The newly developed housed swine heat stress index (HS2I) combines TESA measurements and optional wetted skin to assess the potential for HS onset. Custom software interfaced with a multifunction data acquisition board was used to condition TESA signals and control EP pumps and sprinkler solenoids. A control algorithm was developed and simulated using data collected during a 23-d period in July 2017 to preliminarily evaluate the robustness and potential control decisions. Linear models developed to predict indoor dry-/wet-bulb temperature showed good agreement with measured data and will be critical for developing a control systems to selects the best cooling system given forecasted ambient conditions.

Data collected on 17 swine finishing rooms from the Midwest region of the United States was used to study the relationship between infiltration rate and selected room characteristics. Effect of individual room characteristics on room infiltration rate were tested by simple linear regression (SLR) while multiple linear regression (MLR) was used to develop models for improved prediction. SLR results revealed that the total (I-t) and other (I-o; non-curtain/fan locations) swine finishing room infiltration rates were inversely related to room width and directly related to room length and ceiling height. As expected, rooms with higher curtain end pocket overlap, curtain closure overlap distance, and in excellent condition had reduced curtain infiltration (I-c). To reduce fan infiltration (I-f), fan and pump-out cover perimeter and fan area should be minimized. Power law equations fitted for groups of rooms were found ineffective in accounting for the large variability in infiltration rates of swine finishing rooms as compared to MLR models. MLR models developed for I-t and I-o prediction at 10, 20, and 30 Pa pressure differences were found to improve the prediction over power law models for groups of rooms. At 20 Pa, prediction differences compared with individual room measurements for It rate using the suggested MLR model, as compared to power law models for groups of rooms, were less by at least 61%; whereas, in the case of I-o rate, prediction differences compared with individual room measurements were less by at least 49%. Recommendations made in this article, with respect to the relationship between a particular room characteristic and room infiltration rate, could be used as guiding principles along with other design criterion to reduce infiltration rates in remodeled and new swine finishing rooms.

Current thermal environment (TE) assessment techniques for controlling livestock and poultry facilities often solely use dry-bulb temperature (T-db) and occasionally relative humidity (RH) as assessment parameters. The TE sensor array (TESA; Part 1) provides the opportunity to simultaneously quantify T-db, RH, airspeed, and black globe temperature, but there are no existing methods incorporating these additional TE parameters to accurately assess the TE based on the thermal demands of the animal. Hence, the goal of Part 2 of this series was to develop a technique for evaluating the TE as a function of mean body temperature difference from thermally comfortable (Delta T-b) using body mass, T-db, RH, and airspeed inputs. Multiple regression analysis of the simulated data from the mechanistic thermal balance model for group-housed growing pigs was used to develop the Housed Swine Heat Stress Index (HS2I), which scales impact of the TE from 0 (thermally comfortable) to 10 (severe heat stress). Further, a wetted skin adjustment parameter was included to enable analysing TE with sprinklers. Simulated and predicted Delta T-b agreed well without wetted skin (R-2 = 0.98; RMSE = 0.061 degrees C) and with wetted skin (R-2 = 0.97; RMSE = 0.054 C). The HS2I was applied to assess the spatiotemporal TE data collected by TESA in the commercial grow-finish facility presented in Part 1. HS2I can be used to evaluate the potential impact of the TE in existing facilities and as a design tool to explore different ventilation and cooling strategies. (C) 2018 IAgrE. Published by Elsevier Ltd. All rights reserved.

Air infiltration through unplanned inlets is an integral component of any ventilation process. Air infiltration affects the quality of the room environment and can also increase winter heating costs. Precise data on air infiltration is very important in the design of animal room ventilation systems. Nineteen mechanically ventilated (negative pressure type) swine finishing rooms in Iowa were tested for their air infiltration potential. Using the data of 17 rooms, air infiltration rate through the whole room (i.e., total air infiltration, I-t), curtains (I-c), fans (I-f), and net building shell (other components, I-o) were quantified. Power law equations were developed for infiltration prediction of different room configurations grouped on the basis of their construction style, age, ceiling material, curtain perimeter, and fan backdraft shutter area. All power law models reported in this study were adjusted to predict standard (sea level) infiltration rates. At 20 Pa pressure difference across the room envelope, the predicted standard I-t infiltration rate for the 17 rooms was 5.96 +/- 1.49 air changes per hour (ach); whereas, the predicted standard I-c, I-f, and I-o infiltration rates were 1.49 +/- 1.00 ach (about 25% of I-t), 1.52 +/- 1.38 ach (about 26% of I-t) and 2.90 +/- 1.42 ach (about 49% of I-t), respectively. The standard I-t infiltration rate trended lower for rooms (n=8) from single room layout barns (5.85 +/- 1.66 at 20 Pa), rooms (n=8) having a non-metal ceiling (5.85 +/- 2.15 at 20 Pa), and rooms (n=8) aged <= 13 years (5.85 +/- 2.15 at 20 Pa). The infiltration resistances, calculated using standard sea level infiltration rates, indicated that the curtain, fan, and other infiltration areas of swine finishing rooms changes with barn layout, age, construction material, and pressure difference. Methodology to convert measured infiltration rates to standard sea level weather conditions and to any desired room location was included.

Transport of weaned pigs poses special challenges because of their size and thermal needs as well as the extended distances and transport times. The resultant economic impact can be substantial. Compared to transport of market pigs, weaned pigs generally encounter much farther travel distances with different adapting abilities to the environmental conditions. The objectives of this study were: 1) to characterize the environmental conditions within a typical transport trailer for weaned piglets to determine if current management practices and trailer design provides an acceptable environment as evidenced by mortality rates and environmental parameters, and 2) to analyze airflow patterns of the tranport trailer using a scale model in a wind tunnel. Data from 78 usable transport trips were collected for air temperature in each trailer compartment, ambient temperature, distance traveled, time traveled, stocking density, and mortality by compartment. The 78 trips had an average distance of 778 km (range of 264 to 1016 km), travel time of 8.51 h (range of 3.4 to 12.3 h), and mortality rate of 0.031% (range of 0 to 1.11%). There was no significant difference in mortality by compartment (p>0.05). The results indicate that if pigs are transported at a higher stocking density, the compartment temperatures would be similar during cold weather (e.g., 2 degrees C). Under mild weather condition (e.g., 16 degrees C), significant differences could exist in compartment temperature between part of the upper deck (Upper 1) and the lower deck (Lower 4) (p<0.05). In comparison, no significant differences were found at warm conditions (e.g., 29 degrees C) (p>0.05). In addition to the weather influence, in-trailer environment is affected by the side openings which may be adjusted by the driver. A 1/7th scale model of a livestock trailer was placed in a wind tunnel to examine flow characteristics within the trailer including velocity by location and direction. Trials were run with and without the front vents covered and with and without compartment partitions in place. The sides remained open for all trials. Centerline velocities in the compartments varied from 11% to 22% of the wind tunnel speed with trailer averages ranging from 14% to 16%. Pen partitions within the trailer had an impact on centerline velocity averaging 14.3% to 15.4% of wind tunnel speed (p<0.05); whereas covering the front vents or not had no effect on the centerline velocities. When the front air vents on the trailer were uncovered, air flow was from the back of the trailer toward the front. When the front air vents were covered, air flow direction was mixed with most of the upper compartments having front to back flow and most of the lower compartments having back to front flow. The lower rear compartment (Lower 4) tended to have the lowest air velocity rates with Upper 3 and Upper 4 being only slightly higher. Lower 3, Lower 2, and Upper 1 compartments tended to have the highest air velocities. Conclusions support the further investigation of changes to compartment partition and trailer rear panel design, as well as investigation of additional trailer options that may enhance or deter air flow through the trailer.

The thermal environment (TE) inside swine facilities has a substantial impact on animal growth performance and facility energy usage; therefore, proper control and measurement are required to maintain the optimal TE that maximizes feed efficiency and consumes minimal resources. An inexpensive and novel network of 44 thermal environment sensor arrays (TESAs) capable of capturing the spatial and temporal distribution of the TE were deployed in August 2016 inside a two-room (designated as North; N and South; S), wean-finish barn (~1200 hd and 22 TESAs per room) and placed about 1.8 m above the slatted floor. All TESAs simultaneously measured and averaged 20 samples of dry-bulb temperature, back globe temperature, airspeed, and relative humidity at 1 min intervals. The objectives of this research were to: (1) summarize the TE observations from this monitoring period and (2) develop some preliminary analysis methods to quantitatively compare the TE in each room. Each room of the fully mechanically, power-tunnel ventilated facility featured independent TE control (i.e., fan, heater, inlet, and tunnel curtain operation) by a unique ventilation controller. A set point uniformity coefficient (γSP; binned by ambient temperature; ta) was used to assess ventilation controller performance and a two-sample (from random subsampling of ta bins) t-test was used to test if γSP in each room was statistically different. Results showed a statistically significant difference between N and S room γSP for ta bins <8°C (p < 0.01; p < 0.01; p < 0.01). No statistically significant difference was found between N and S room γSP for ta bins >8°C (p = 0.26; p = 0.07; p = 0.73; p = 0.31). This is a preliminary and novel approach to assessing ventilation controller performance and future approaches will need incorporate all parameters of the TE.

In modern animal agriculture, implementation of practices improving the sustainability of livestock production has been a key goal. As a means of achieving this objective, farmers decreased the inputs for live production through nutrition and equipment modifications to decrease the feed and water wastage. These practices and changes have also impacted manure characteristics. Thus, the objectives of this work were to report the impact of changing to wet-dry feeders and manure storage types had on manure production and nutrient concentrations, and discuss these impacts on farm manure management planning. This study examined manure samples from 2001 to 2015 and manure applications from 2007 to 2015 from swine finishing facilities in Iowa that utilized deep pits, vats, and lagoons for manure storages. Over time the manure concentrations for nitrogen, phosphorus and potassium increased across all storage types. Pits had the highest concentrations of all nutrients. A significant increase in nutrient concentrations were seen when changing from dry feeders to wet-dry feeders in deep pit and lagoon storage systems for nitrogen, phosphorus and potassium. The changes in vats were not significant. Results and analysis of the manure production and manure applications showed that manure storage type leads to different estimates of nutrient production, presumably due to differences in nutrient conservation during storage. This study will examine the changes in application land coverage and application rates over time as it relates to the change in manure concentrations in nitrogen and phosphorus.

Pigs have a relatively low capacity to dissipate excess body heat and depend more on reducing metabolic heat production through a reduction in voluntary feed intake in hot conditions, resulting in a growth performance decrease. Effectiveness of current cooling devices (e.g., evaporative coolers or sprinklers) in facilities is governed by the Water Vapor Pressure (WVP) concentration gradient between the air (a function of dry-bulb temperature, tdb; relative humidity, RH; and atmospheric pressure) and saturated WVP at a wet surface. Traditional sprinkler control systems (TSCS) often operate solely on tdb feedback and at fixed “off” intervals to allow dispersed water to evaporate. This control strategy does not account for the WVP concentration gradient; hence, water is wasted and only a limited amount of latent heat can be removed from the animal. Therefore, the objectives were to develop and simulate a novel variable interval sprinkler control system (VISCoS) that dynamically changes the “off” interval based on tdb, RH, and airspeed feedback. A theoretical convective mass transfer model (i.e., evaporation) was developed to estimate water evaporation rate as a function of the thermal environment, surface area, skin temperature, and volume of water applied. A pig's geometry was assumed a cylinder approximately 30% wet with a 1-mm film of water. The feasibility of implementing VISCoS was evaluated at six locations (AZ, IA, MN, MO, IN, and NC) by simulating water usage for a 1000 hd, mechanically ventilated, grow-finish building with an assumed water delivery (75.71 L/min), sprinkler “on” time (30 s), and constant BW (100 kg). Typical meteorological year 3 weather data (365 d) was used to determine outdoor tdb and RH at each location, where indoor tdb was assumed 2°C greater than outdoor tdb with a 2 m/s air velocity across the animal's back. The VISCoS performance was compared with two TSCSs with fixed “off” intervals (15 and 30 min; “on” tdb ≥ 29.44°C). Simulation results for each region showed water usage for 15 min (154, 72, 60, 50, 80, 164 m3) and 30 min (79, 37, 31, 26, 41, 83 m3) “off” interval TSCS to be greater than VISCoS (49, 15, 8, 10, 17, 44 m3). Duration (±SD) for complete water evaporation estimated by VISCoS (19.6 ± 1.4, 28.0 ± 3.6, 27.8 ± 2.5, 31.8 ± 6.5, 32.2 ± 3.3, 26.9 ± 3.3 min) varied by region and provides insight on incorporating more thermal environment measurements to reduce water usage in swine facilities.

The recent shift in commercial swine breeding-gestation-farrowing facilities to incorporate filtered ventilation systems raises numerous questions about system performance and longevity of filters. It has been shown that air filtration with ASHRAE standard MERV 14, 15 and 16 type filters are effective at reducing the aerosol spread of PRRSV and Mycoplasma hypopneumonia. The areas that are lacking in current literature is relevant filter testing methodology and criteria for determining filter end of life in an agricultural setting. To address this, a mobile air filter testing unit (MAFT) was developed to address the testing needs for the swine industry to evaluate on-site filter performance. The test duct is capable of measuring pressure drop and airflow for a pre-filter and main V-bank filter combination. The unique feature of this system is the ability to test filters on site and to test the same filter at different points in time. It was shown through validation that MAFT was accurate at measuring the airflow through the filter combinations in comparison to an ASHRAE 52.2 standard lab.