Evaluation of Truck Cab Decontamination Procedures following Inoculation with Porcine Epidemic Diarrhea Virus and Porcine Reproductive and Respiratory Syndrome Virus

This experiment aimed to evaluate commercially available disinfectants and their application methods against porcine epidemic diarrhea virus (PEDV) and porcine reproductive and respiratory syndrome virus (PRRSV) on truck cab surfaces. Plastic, fabric, and rubber surfaces inoculated with PEDV or PRRSV were placed in a full-scale truck cab and then treated with one of eight randomly assigned disinfectant treatments. After application, surfaces were environmentally sampled with cotton gauze and tested for PEDV and PRRSV using qPCR duplex analysis. There was a disinfectant × surface interaction (p < 0.0001), indicating a detectable amount of PEDV or PRRSV RNA was impacted by disinfectant treatment and surface material. For rubber surfaces, 10% bleach application had lower detectable amounts of RNA compared to all other treatments (p < 0.05) except Intervention via misting fumigation, which was intermediate. In both fabric and plastic surfaces, there was no evidence (p > 0.05) of a difference in detectable RNA between disinfectant treatments. For disinfectant treatments, fabric surfaces with no chemical treatment had less detectable viral RNA compared to the corresponding plastic and rubber (p < 0.05). Intervention applied via pump sprayer to fabric surfaces had less detectable viral RNA than plastic (p < 0.05). Furthermore, 10% bleach applied via pump sprayer to fabric and rubber surfaces had less detectable viral RNA than plastic (p < 0.05). Also, a 10 h downtime, with no chemical application or gaseous fumigation for 10 h, applied to fabric surfaces had less detectable viral RNA than other surfaces (p < 0.05). Sixteen treatments were evaluated via swine bioassay, but all samples failed to produce infectivity. In summary, commercially available disinfectants successfully reduced detectable viral RNA on surfaces but did not eliminate viral genetic material, highlighting the importance of bioexclusion of pathogens of interest.

Isolation of porcine reproductive and respiratory syndrome virus from feed ingredients and complete feed, with subsequent RT-qPCR analysis

We used virus isolation (VI) to determine tissue culture infectivity and reverse-transcription quantitative PCR (RT-qPCR) to determine the stability of porcine reproductive and respiratory syndrome virus 2 (PRRSV) strain P129 in solvent-extracted soybean meal (SBM), dried distillers grains with solubles (DDGS), complete swine feed (FEED), or medium (DMEM) at 4°C, 23°C, or 37°C for up to 3 d. Samples of each treatment were taken at regular intervals and processed. Supernatant was titrated and used to inoculate confluent MARC-145 cells to determine infectivity. RNA was extracted from each supernatant sample and tested by RT-qPCR to determine any change in detectable virus RNA across matrix type, temperature, and time. An interaction (p = 0.028) was observed for matrix × temperature × hour for live virus detected by VI. At 4°C, the concentration of infectious virus was greatest in DMEM, intermediate in SBM, and lowest in DDGS and FEED. DMEM also had the greatest concentration of infectious PRRSV at 23°C over time; a higher infectious virus concentration was maintained in SBM for longer than in DDGS or FEED. At 37°C, a greater concentration of infectious virus was sustained in DMEM than in the feedstuffs, with concentrations decreasing until 48 h post-inoculation. Only matrix type influenced the quantity of viral RNA detected by RT-qPCR (p = 0.032). More viral RNA was detected in the virus control than in DDGS; SBM and FEED were intermediate. By VI, we found that infectious virus could be harbored in SBM, DDGS, and FEED for a short time.

Evaluating a dry vs. wet disinfection in boot baths on detection of porcine epidemic diarrhea virus and porcine reproductive and respiratory virus RNA

Maintaining biosecurity between swine barns is challenging, and boot baths are an easily implementable option some utilize to limit pathogen spread. However, there are concerns regarding their efficacy, especially when comparing wet or dry disinfectants. The objective of this study was to evaluate the efficacy of boot baths in reducing the quantity of detectable porcine epidemic diarrhea virus (PEDV) and porcine reproductive and respiratory syndrome virus (PRRSV) genetic material using wet or dry disinfectants. Treatments included 1) control, 2) dry chlorine powder (Traffic C.O.P., PSP, LLC, Rainsville, AL), and 3) wet quaternary ammonium/glutaraldehyde liquid (1:256 Synergize, Neogen, Lexington, KY). Prior to disinfection, rubber boots were inoculated with 1 mL of a co-inoculants of PRRSV (1×10 5 TCID50/mL) and PEDV (1×10 5 TCID50/mL) and dried for 15 minutes. After the drying period, a researcher placed the boot on the right foot and stepped directly on a stainless steel coupon (control). Alternatively, the researcher stepped first into a boot bath containing either the wet or dry sanitizer, stood for 3 s, and then stepped onto a steel coupon. After one minute, an environmental swab was then collected and processed from each boot and steel coupon. The procedure was replicated 12 times per disinfectant treatment. Samples were analyzed using a duplex qPCR at the Kansas State Veterinary Diagnostic Laboratory. Cycle threshold values were analyzed using SAS GLIMMIX v 9.4 (SAS, Inc., Cary, NC). There was no evidence of a disinfectant × surface × virus interaction (P &gt; 0.10). An interaction between disinfectant × surface impacted (P &lt; 0.05) the quantity of detectable viral RNA. As expected, the quantity of the viruses on the coupon were greatest in the control, indicating that a contaminated boot has the ability to transfer viruses from a contaminated surface to a clean surface. Comparatively, the dry disinfectant treatment resulted in no detectable viral RNA on either the boot or subsequent coupon. The wet disinfectant treatment had statistically similar (P &gt; 0.05) viral contamination to the control on the boot, but less viral contamination compared to the control on the metal coupon. In this experiment, a boot bath with dry powder was the most efficacious in reducing the detectable viral RNA on both boots and subsequent surfaces.

53 Evaluating the Efficacy of Boot Baths with Wet and Dry Disinfectants for Porcine Epidemic Diarrhea Virus and Porcine Reproductive and Respiratory Syndrome Virus

Maintaining biosecurity between barns is challenging. Boot baths, either wet or dry, can be implemented to limit pathogen spread. The objective was to evaluate the efficacy of boot baths using wet or dry disinfectants for porcine epidemic diarrhea virus (PEDV) and porcine reproductive and respiratory syndrome virus (PRRSV). Treatments included 1) control, 2) wet disinfectant (Synergize, Neogen, Lexington, KY), and 3) dry disinfectant (Traffic C.O.P., PSP, LLC, Rainsville, AL). Prior to disinfection, 0.5 mL of both PRRSV (~1×105 TCID50/mL) and PEDV (~1×105 TCID50/mL) was placed onto a new boot with a layer of autoclaved corn dust and allowed to dry for 15 minutes. After the mixture dried, the boot was put on and stepped into its respective boot bath. After 3 seconds, the boot was lifted out of the bath and stepped onto a stainless-steel coupon to simulate walking through a facility. Both boot and coupon were allowed to dry for 1 minute before swabs were taken from both surfaces. Samples were analyzed in a duplex PCR at the Kansas State Veterinary Diagnostic Laboratory. Cycle threshold values were analyzed using SAS GLIMMIX v 9.4 (SAS, Inc., Cary, NC). There was no evidence of a treatment×surface×virus interaction (P &gt; 0.10). The interaction between treatment×surface impacted (P &lt; 0.05) the quantity of detectable RNA. The control had greater concentration of virus on the coupon than the boot. The reverse was true for boots treated with wet disinfectant, where the boot had a greater concentration of virus than the coupon. Treatment×virus also impacted detectable RNA (P &lt; 0.05), where wet and control boots had greater quantities of PEDV RNA than PRRSV. There was no detectable virus when dry disinfectant was used. For this trial, dry disinfectant was the most efficacious in reducing the viral RNA on both boots and subsequent surfaces; however, further research in commercial settings is warranted.

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PSV-5 Effects of Benzoic Acid and an Essential Oils Blend on Detection of Swine Viruses in Inoculated Swine Feed and Premix

Feed has been shown to harbor viable viruses over an extended period. This study investigated the use of benzoic acid (BA) and an essential oils blend (EO) to mitigate the presence of porcine epidemic diarrhea virus (PEDV), porcine reproductive and respiratory syndrome virus (PRRSV), and Senecavirus A (SVA) in a complete diet (Exp. 1) and a vitamin premix (Exp. 2). Experiment 1 consisted of a control with no additive, 0.5% BA, 0.5% BA and 200 ppm EO, 0.3% BA and 120 ppm EO, and 0.25% BA and 100 ppm EO. Feed samples were inoculated with PEDV, PRRSV, and SVA. For Exp. 2, the control contained no additive, and treatment had 2.68% EO included to mitigate PEDV. Inoculated feed or premix was stored at room temperature with sampling points at 2, 5, and 15 d post-inoculation (dpi). Samples were analyzed using triplex qRT-PCR to detect changes in RNA quantities for all viruses. Detectible PRRSV in the feed demonstrated a quadratic decrease over time (P = 0.038). A significant treatment × day interaction was observed in the feed for both PEDV (P = 0.008) and SVA (P &lt; 0.001). The 0.5% BA treatment had greater (P &lt; 0.05) amounts of detectible PEDV on d 2 and 5 and decreased detectible PEDV on d 15 compared with control. The 0.5% BA treated feed demonstrated decreased (P &lt; 0.05) detectable SVA at 2 dpi but greater detectible SVA at 15 dpi compared with control. Both PEDV and SVA demonstrated viral degradation over time. The use of the EO in the vitamin premix had no evidence of main or interactive effects. In conclusion, 0.5% BA decreased PEDV at 15 dpi, but BA and EO mitigation in this model did not provide consistent evidence for increased viral degradation. However, time decreased detectability of all three viruses.

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Using caloric efficiency to estimate the net energy value of expelled, extruded soybean meal relative to dehulled, solvent-extracted soybean meal and its effects on growth performance of nursery pigs

This study aimed to estimate the net energy (NE) value of expelled, extruded soybean meal (MSBM) relative to dehulled, solvent-extracted soybean meal (SSBM) and determine its effects on growth performance of late nursery pigs. A total of 297 pigs (DNA 241 × 600) were weaned (BW 5.10 kg) and placed into 60 pens (2 rooms of 30 pens) with 5 pigs per pen balanced by gender and weaning weight. Pigs were fed a common diet for 21 d. Then, pens of pigs (BW 9.3 kg) were randomly assigned to one of five treatments to provide 12 replications per treatment. Treatments consisted of increasing amounts of MSBM replacing SSBM in the diet (0%, 25%, 50%, 75%, and 100%). All diets were fed for 28 d and were formulated to 1.30% standardized ileal digestible lysine and met or exceeded requirements for amino acids, calcium, and phosphorus. The SSBM diet was formulated to 2,421 kcal/kg and NE was not balanced between diets. Analyzed values for CP, EE, CF, and total lysine for the SSBM were 47.28%, 0.47%, 3.80%, and 3.00%, whereas the MSBM contained 47.41%, 6.88%, 5.32%, and 2.99%, respectively. The MSBM had increased values for KOH solubility and trypsin inhibitor (83.62% and 7,026 TIU/g) compared to the SSBM (73.05% and 3,011 TIU/g), whereas urease activity was similar between the two (0.03 and 0.02 Δ pH, respectively). Data were analyzed using Proc GLIMMIX (SAS 9.4; Cary, NC) with pen as the experimental unit and room as the blocking factor. There was no evidence of differences in ADG and ADFI in pigs fed diets with increasing concentrations of MSBM. Pigs fed diets with increasing concentrations of MSBM had improved (linear, P < 0.001) G:F and caloric efficiency on an NE basis. Using caloric efficiency to estimate NE of the MSBM relative to SSBM, MSBM was estimated to have a value of 2,566 kcal/kg. In conclusion, MSBM contains approximately 123% of the energy of SSBM, which improved feed efficiency when fed to nursery pigs.

Assessment of soy-based imports into the United States and associated foreign animal disease status

Soy-based products are known to pose a viable risk to U.S. swine herds because of their ability to harbour and transmit virus. This publication aimed to evaluate soy imports into the United States as a whole and from foreign animal disease positive (FAD-positive) countries to determine which products are being imported in the highest quantities and observe potential trends in imports from FAD-positive countries. Import data were accessed through the United States International Trade Commission website (USITC DataWeb) and summarized using R (version 4.0.2, R core team, Vienna, Austria). Twenty-one different Harmonized Tariff Schedule (HTS) codes were queried to determine quantities (metric tonnes, MT) and breakdown of different soy product types being imported into the United States from 2015 to 2020. A total of 78 different countries exported soy products to the United States in 2019 and 2020 with top contributors being Canada (546,467 and 481,497 MT, respectively), India (397,858 and 430,621 MT, respectively) and Argentina (122,116 and 79,471 MT, respectively). Soy oilcake (582,273 MT) was imported in the largest quantities, followed by organic soybeans (270,194 MT) and soy oil (134,436 MT) for 2020. Of the 78 countries, 46 had cases of FAD reported through the World Organization for Animal Health (OIE) World Animal Health Information Database (WAHIS). Top exporters of soy products to the United States from FAD-positive countries in 2019 and 2020 were India (397,858 and 430,621 MT, respectively), Argentina (122,116 MT in 2019) and Ukraine (40,293 and 56,392 MT, respectively). The risk of FAD introduction to the United States through soy imports can fluctuate based on where FAD outbreaks are occurring, shipping methods and end usage of products. A system to monitor these factors could help make future decisions about trade and risk of FAD introduction to U.S. swine herds.

31 Using Caloric Efficiency to Estimate the Energy Value of Expelled, Extruded Soybean Meal Relative to Dehulled, Solvent-extracted Soybean Meal and Its Effects on Growth Performance of Nursery Pigs

This study aimed to estimate the net energy value of expelled, extruded soybean meal (MSBM) relative to dehulled, solvent-extracted soybean meal (SBM) and determine its effects on growth performance of late nursery pigs. Analyzed values for CP, EE, CF, and lysine for the SBM were 47.28%, 0.47%, 3.80%, and 3.00% while the MSBM contained 47.41%, 6.88%, 5.32%, 2.99% respectively. A total of 297 pigs (DNA 200 x 400) were placed into 60 pens (2 rooms of 30 pens) with 5 pigs per pen balanced by gender and weaning weight. Pigs were fed common diets for 21 days. Then, pens of pigs (BW 9.3 kg) were randomly assigned to one of five treatments to provide 12 replications per treatment. Treatments consisted of increasing amounts of MSBM replacing SBM in the diet (0, 25, 50, 75, 100%). All diets were fed for 28 days and were formulated to 1.30% standardized ileal digestible lysine and met or exceeded NRC (2012) recommendations for lysine:amino acids, calcium, and phosphorus. The SBM diet was formulated to 2421 kcal/kg and net energy (NE) was not balanced between diets. Data were analyzed using Proc GLIMMIX (SAS 9.4; Cary, NC) with pen as the experimental unit and room as the blocking factor. There was no evidence of differences in ADG and ADFI in pigs fed diets with increasing concentrations of MSBM. Pigs fed diets with increasing concentrations of MSBM had improved (linear, P &lt; 0.001) G:F and caloric efficiency on an NE basis. In conclusion, using caloric efficiency to estimate NE of the MSBM relative to SBM, MSBM was estimated to have a value of 123% of SBM NE or 2566 kcal/kg. This increase in NE resulted in improved feed efficiency of nursery pigs.

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120 Impact of a Two-phase Lactation Feeding Program on Farrowing and Weaning Performance of Sows

The U.S. Pork Industry uses a one-phase lactation feeding program based on logistical constraints and ease. The objective of this experiment was to quantify the sow performance differences between a one-phase and two-phase lactation feeding program to allow pork producers to calculate the economics of switching to a two-phase lactation feeding program. 257 gilts and sows (PIC 1050; Hendersonville, TN) were randomly assigned to a two-phase or one-phase lactation feeding program. Animals on the one-phase treatment were fed a typical lactation diet (2.55 Mcal/kg NE, 12.7% NDF, 0.99% SID Lys) for the duration of the experiment. Animals on the two-phase treatment were fed a high-fiber, lower-lysine transition diet (2.35 Mcal/kg NE, 18.5% NDF, 0.65% SID Lys) from the time they were loaded into the farrowing room until switching to the lactation diet on d 3 post-farrowing. From loading to farrowing, animals on both treatments were fed 1.82 kg/d, split between 2 meals at 630 and 1530 h. Daily feed amount was increased on the farrowing day and the 2 subsequent days (2.73, 4.09, 5.45 kg) until allowed ad libitum access to the lactation feed for both treatment groups on the third day after farrowing. Data were analyzed using Proc MIXED (SAS 9.4; Cary, NC) with treatment as the main effect and sow as the experimental unit. Comparing treatments, no significant differences on total born (one-phase = 16.2 vs. two-phase = 16.0, pigs/litter), live born (one-phase = 14.6 vs. two-phase = 14.4, pigs/litter), stillborn rate (one-phase = 8.1% vs. two-phase = 7.4%), number weaned (one-phase = 12.1 vs. two-phase = 11.9, pigs/litter), or weaning weight (one-phase = 5.67 vs. two-phase = 5.71, kg/pig; P ≥ 0.37) were detected. In conclusion, a two-phase lactation feeding program did not impair sow performance can be utilized to reduce lactation feed costs by $0.42/female/lactation cycle.