Sponsors. We thank the following sponsors: Formatting Tina Smith Graphics CD-ROM David Brown

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1 Sponsors We thank the following sponsors: Gold Boehringer-Ingelheim Vetmedica, Inc. Pfizer Animal Health Bronze Alpharma Animal Health Bayer Animal Health Intervet/Schering Plough Animal Health National Pork Board Copper AgStar Financial Services American Association of Swine Veterinarians IDEXX IVESCO Novartis Animal Health US, Inc. Novus International Inc. PIC USA PigCHAMP University of Minnesota Institutional Partners College of Veterinary Medicine University of Minnesota Extension College of Food, Agriculture and Natural Resources Sciences Formatting Tina Smith Graphics CD-ROM David Brown Logo Design Ruth Cronje, and Jan Swanson; based on the original design by Dr. Robert Dunlop ii The University of Minnesota is committed to the policy that all persons shall have equal access to its programs, facilities, and employment without regard to race, color, creed, religion, national origin, sex, age, marital status, disability, public assistance status, or sexual orientation Allen D. Leman Swine Conference

2 Real time measurement of GHG Emissions from pig barns Larry D Jacobson, Professor BBE Dept., University of Minnesota Introduction Recent national and global trends are forcing the US animal industries, including the pork industry, to determine and reduce their carbon footprint. One portion of that carbon footprint is related to the on-farm phase of pork production while other aspects of the carbon footprint relate to production of feed (land use changes, fuel, fertilizer, and water) to product processing, packaging, and distribution (Steinfield et al, 2006). The greenhouse gas (GHG) emissions from pork production can be divided into emissions of carbon dioxide (CO 2 ), methane (CH 4 ), and nitrous oxide (N 2 O). The largest source of CO 2 emissions in pig production buildings is the animal s respiration which is generally not a large portion of the GHG total. Thus, CH 4 and N 2 O are the primarily GHG of interest for pig buildings and it is well known that these two gases are respectively, 21 and 310 times more potent GHG than CO 2. Literature review Very limited CH 4 and N 2 O emission data has been collected directly from pig or other livestock buildings. A national assessment paper (Moffitt, 2006) used a general prediction model based on the animal s manure production values, specifically volatile solids, resulted in estimated methane emission values of 800, 1,100, and 1,200 g/d/au (AU = 500 kg or 1100 lbs of animal weight) for turkeys, finishing pigs, and dairy cows respectively. Computer models are also being developed to estimate GHG emissions using various model inputs and algorithms (for example Dairy GHG Model (Rotz. A., 2009)). Actual measurements from animal buildings yielded considerably smaller CH 4 emission factors. Dong et al, (2007) reported on CH 4 emissions for various swine buildings and for finishing pigs in China and measured an average of 32 g/d/au. European studies in Germany (Gallmann, et al. 2003) found a range of 70 to 135 g CH 4 /d/au for finishing pigs on slatted floors while research in Italy (Guarrino, et al, 2003) reported an average of 190 g/d/au for CH 4 emissions for finishing or fattening pigs on a slatted floor. Recent national studies are being conducted to measure the emissions of GHG s from livestock production, such as the ongoing Assessment of Carbon Footprint Contributions to Milk Products by US Dairies add-on NAEMS project funded by the Dairy Management Inc. (DMI). This project is collecting CO 2, CH 4, and N 2 O emissions from 5 dairies (buildings and associated manure storages) that were used in the NAEMS project, by continuous long-term monitoring at each of the individual dairy sites. Most of the other projects are also continuously measuring GHG gases. However, in Europe it has been determined that long term monitoring of single sites does not result in data that can be applied across similar farms as the farm to farm variability is not accounted for, and is sometimes greater than the within farm variability (Ogink et al, 2008). These same researchers have developed protocols for determining gas (in their case ammonia) emission factors using a 24-hour cumulative sampling protocol. This protocol specifies that sampling take place at four (or more) representative farm sites with six independent sampling events at each farm location distributed evenly over a 12 month period (one random sample per every two month at each farm site). This protocol allows for a variety of air flow sampling methods and gas analysis techniques. Materials and methods To demonstrate the real time measurement approach, gas emission monitoring was done in 2008/2009 on a 2800-head capacity, deep-pitted, mechanically ventilated grow-finish pig site in West-Central Minnesota (Figure 1). This style of pig finishing building is very common in Minnesota and the Midwest. The barn was with a divider wall down the middle creating two rooms Each of these rooms had 14 pens holding 100 pigs per pen. Each room had an independent ventilation system with ceiling inlets (Model PFA temperature actuated ) for winter ventilation and an endwall curtain (4.5 43, temperature actuated) for summer tunnel ventilation. Inlets, curtains, fans and heaters were controlled by a Phason controller using temperature setpoints. 1 st and 2 nd stage ventilation was provided by 4-24 diameter blade, direct-drive fans (Multifan V6E6308M60100, Bloomington, Illinois). These fans were located in the pit pumpouts on the north room (NR) and in the sidewalls in the south room (SR). The other four ventilation stages were provided by two 36 diameter blade, direct-drive fans 2010 Allen D. Leman Swine Conference 95

3 Larry D Jacobson (J&D Manufacturing, #VFP36S, Eau Claire, WI) and five 52 diameter blade, belt driven fans (J&D manufacturing #VFP50AC, Eau Claire, WI)) installed on the east end of each room. Total fan capacity for each room was approximately 138,000 cubic feet per minute (cfm). The continous monitoring was accomplished by installing sampling lines to collect air from five locations in each pig finishing room and two locations (total of 12) representing the inlet air (Figure 2). Air was pulled continuously through individual Teflon sampling lines (heated lines between instrumentation trailer and building). All samples had a particle filter on the inlet end to prevent dust from entering the gas analyzers. A positive pressure Gas Sampling Figure 1: Barn photo. System (GSS), controlled by Labview software, used solenoids to route air samples to the analyzers for a 10 minute sampling period per sample. Air flow through the sampling lines was maintained above 4 L/m. This resulted in each sampling location being evaluated for gas concentrations every two hours throughout the day. Ammonia concentration was determined using a TEI 17C ammonia analyzer, Thermo Scientific, Waltham, MA), Hydrogen sulfide concentration measured using a TEI 450i hydrogen sulfide analyzer (Thermo Scientific, Waltham, MA) and CO 2 concentrations made using and MSA # 3600 Analyzer (MSA NorthAmerica, Pittsburg, PA). A TEI 55C (Thermo Scientific, Waltham, MA) methane analyzer and a Model 320EU (Teledyne API, San Diego, CA) nitrous oxide analyzer were used for a four week period during the second group of pigs. Temperature measurements were made at each sampling location and in the ambient air near the instrument trailer every minute using thermocouple wires. Relative humidity (%) was measured in each room and in the ambient air using a Vaisala #MHW61Y, (Vantaa, Finland). Static pressure in each room was monitored using a Model 260 Setra pressure transducer (Boxborough MA) and Labview version 6.0 (National Instruments) was used to control the sampling sequence and record data. All building exhaust fans were tested using a Fan Assessment Numeration System or (FANS) testing unit. Monitoring of fan on and off time was done using a current switch attached at the ventilation controller. Table 1 shows the Figure 2: Schematic of barn and approximate location of sampling points. South side West end Top view Allen D. Leman Swine Conference

4 Real time measurement of GHG Emissions from pig barns Table 1: Fan airflow (y = airflow in cfm, = pressure in Pascals) Fan size Number/room Equation 0.05 inch 24-inch 4 y = x x r 2 = 0.85 (SR) y = x x r 2 = 0.77 (NR) 36-inch 2 y = x x r 2 = 0.79 (SR) y = x x r 2 = 0.98 (NR) 50-inch 5 y = x x r 2 = 0.87 (SR) y = x x r 2 = 0.98 (NR) resulting equations used to estimate airflow for each of the fans. Airflow measurements for each fan were calculated using the building static pressure (recorded every minute) and the appropriate fan curve equation. Maximum airflow with all fans operating at 0.05 inches of water gauge is approximately 138,000 cfm or about 100 cfm per pig. Note that the 24-inch fans in the SR had airflow rates from 30 to 40% more than the same fans in the north side because of their placement in the wall without a shroud instead of on top of the pit pump out cover with a shroud. Heater on-off time was monitored using a thermocouple place in front of the heater. Heat-on was assumed when the temperature was over 30 C. Flux rate (mass/time/area) was calculated using the measured concentrations at the exhaust points and the corresponding airflow rates using the following equation. Where FR = µg s -1 m -2 Q = building ventilation rate (m 3 s -1 ) (based on fan curve and static pressure(pa) C = concentration of gas (outlet conc inlet conc) (ppb) w m = molar weight of gas (NH 3 = g mole -1, H 2 S = g mole -1 ) V m = molar volume of air at STP ( m 3 mole -1 ) Tstd = standard temperature K T a = absolute temp ( K) at sampling location ( C ) A = room area (1050 m 2 ) Fan on-off time was also monitored along with heater on-off time. Results Methane concentrations were measured at all sampling points during the second batch of pigs for a two week period, starting 01/22/09. Average concentrations and emissions are reported in Table 2 from 1/22/09 to 2/01/09. Note that although the concentrations are similar between locations and rooms (range of 15 to 24 ppm) the flux is quite variable because of the large dependence on airflow. The real time measurements of methane are shown in Figure 3 for the four exhaust locations in the finishing barn during this two week period. To compare these measurements with those reporting in the literature, one must covert the emission values to grams/day/au, where AU = animal unit of 500 kg. Assuming an average weight of 158 lbs/pig in the south room (SR) and 122 lbs/pig in the NR, then the methane emission rates for the rooms are 140 g/d/au and 103 g/d/au respectively. These values are nearly within the range of 70 to 135 g CH 4 /d/au that was reported by Gallmann, et al for finishing pigs on slatted floors. Although there are definite advantages to real time measurement, especially for growing animal like grow-finishing pigs, this is quite expensive and time consuming. Realistically, as the NAEMS project has demonstrated, only one or two buildings can be monitored per sampling site or trailer. It has been determined in Europe, that long term monitoring of one or two sites does NOT result in (GHG) emission data that can be applied across similar farms as the farm to farm variability is not accounted for, and is sometimes greater than the within farm variability. A 24 hour cumulative sampling protocol for determining gas (in this case GHG) emission factors may better describes the emissions from similar production buildings since it collects data from more barns. Thus, instead of continuous data collection from one or two barns over a full year, 24 hour data will be collected every two months for a full year from multiple buildings so the farm variability that is known to exist can be measured Allen D. Leman Swine Conference 97

5 Larry D Jacobson Table 2: Methane concentrations and flux during the second monitoring period. Location Concentration (ppm) Flux (µg/s/m2) Flux (g/d/pigspace) SR side wall SR end wall SR total 20 NR pit NR end wall NR total 11.5 Figure 3: Real time CH 4 emissions flux for 2 weeks in January, Methand emission, ug/s/m /22/09 to 2/1/09 References 1. Dong, H., Z. Zhu, B. Shang, G. Kang, H. Zhu, and H. Xin Greenhouse gas emission from swine barns of various production stages in suburban Beijing, China. Atmospheric Environment 41(2007): Environmental Protection Agency (EPA): Inventory of U.S. Greenhouse Gases Sources and Sinks, ; EPA 430-R ; April, 2009, Washington D.C. 3. Gallmann, E., E. Hartung, T. Jungbluth Long-term study regarding the emission rates of ammonia and greenhouse gases from different housing systems for fattening pigs-final results. In: Proceedings of the Inter. Symposium on Gas & Odor Emissions from Animal Production, Horsens, Denmark. CIGR, pp Guarrino, M., C. Fabbri, P. Navarotto, L. Valli, G. Moscatelli, M. Rossetti, V. Mazzotta Ammonia, methane, and nitrous oxide emissions and particulate matter concentrations in two different buildings for fattening pigs. In: Proceedings of the International Symposium on Gas and Odor Emissions from Animal Production, Horsens, Denmark. CIGR, pp Moffitt, David, R. Kellogg National assessment of methane emissions from livestock and poultry manure. ASABE paper # Ogink, N, J. Mosquera, R. Melse Standardized testing procedures for assessing Ammonia and odor Emissions from animal housing systems in The Netherlands. In Proceedings from the National Conference on Mitigating Air Emissions from Animal feeding Operations. Ames, Iowa Allen D. Leman Swine Conference

6 Real time measurement of GHG Emissions from pig barns 7. Rotz. A Dairy GHG Model. Downloaded from November USDA/ARS Steinfield, H., Gerber H.P., T. Wassenaar, V. Castel, M. Rosales, C de Hann Steinfeld, H., P Gerber, T. Wassenaar, V. Castel, M. Rosales, C. De Haan Livestock s long shadow- Environmental issues and options. FAO report, November, centre.org/en/library/key_pub/longshad/a0701e00.ht 2010 Allen D. Leman Swine Conference 99