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.

Effect of the pelleting process on diet formulations with varying levels of crystalline amino acids and reducing sugars on digestibility in growing pigs

The objective of this experiment was to determine the effects of pelleting on the standardized ileal digestibility (SID) of amino acids (AA) and crude protein (CP) in diets with or without increased concentrations of free AA and reducing sugars (RS). Eight individually housed, ileal cannulated barrows (initially 31.4 kg) were allotted to an 8 × 8 Latin square with eight diets and eight 7-d periods with ileal digesta collected on days 6 and 7. Treatments were arranged in a 2 × 2 × 2 factorial with the main effects of diet form (mash or pellet), crystalline AA (low or high), or RS (low or high), provided by distillers dried grains with solubles and bakery meal. Diets were pelleted to achieve a hot pellet temperature of 85 to 88 °C. Data were analyzed as a Latin square design using the GLIMMIX procedure of SAS 9.4. A feed form × RS interaction (P < 0.026) for SID of tryptophan was observed. Feeding pelleted low RS diets increased SID of tryptophan compared with mash high and low RS diets, and pelleted high RS diets. For the main effects of feed form, the SID of total AA, CP, and indispensable AA was greater (P < 0.042) in pelleted diets compared with mash diets. For the main effects of crystalline AA, pigs fed high crystalline AA had increased (P = 0.007) SID of tryptophan and decreased (P = 0.050) SID of histidine compared with those fed low crystalline AA diets. For the main effects of RS, high RS diets had decreased (P < 0.05) SID of total AA, CP, and indispensable AA compared with low RS diets. In conclusion, pelleting diets increased AA digestibility, and pelleting diets with increased crystalline AA or RS did not affect the improvement in AA digestibility from pelleting. Diets formulated with high crystalline AA had increased SID of tryptophan. Formulating diets with high RS resulted in decreased AA digestibility compared with corn-soybean meal-based diets.

Evaluation of a microencapsulated form of zinc oxide on weanling pig growth performance, fecal zinc excretion, and small intestinal morphology

A total of 300 pigs (DNA 200 × 400; initially 6.0 ± 0.08 kg body weight [BW]) were used in a 42-d study to evaluate a microencapsulated form of zinc oxide. At weaning, pigs were randomly allocated to pens, and pens were randomly assigned to dietary treatments with 5 pigs per pen and 12 pens per treatment. Dietary treatments were 1) negative control (CON; standard nursery diet containing 110 ppm Zn in the form of zinc sulfate from trace mineral premix); 2) control diet with 400 ppm added Zn from ZnO included in phases 1 and 2 (Low-ZnO); 3) control diet with 3,000 ppm added Zn from ZnO included in phase 1 and 2,000 ppm added Zn from ZnO included in phase 2 (High-ZnO); 4) control diet with 400 ppm added Zn from microencapsulated ZnO included in phases 1 and 2 (Low-MZnO; Vetagro S.p.A., Reggio Emilia, Italy); 5) control diet with 3,000 ppm added Zn from microencapsulated ZnO in phase 1 and 2,000 ppm added Zn from microencapsulated ZnO in phase 2 (high-MZnO; Vetagro S.p.A., Reggio Emilia, Italy). On days 10 and 28, fecal samples from 2 pigs per pen were collected for fecal Zn concentrations, and on day 28, 30 pigs (n = 6) were euthanized, and small intestinal tissues were collected to evaluate morphology. For the entire treatment period (days 0 to 28) there was no evidence of differences in average daily gain (ADG), average daily feed intake (ADFI), or G:F (P > 0.05). During the common phase 3 (days 28 to 42) pigs fed the negative control, High-MZnO, or Low-MZnO had improved (P < 0.0001) ADG and ADFI compared to pigs fed High- or Low-ZnO. For the entire experiment (days 0 to 42), pigs fed Low-ZnO or High-ZnO had reduced (P < 0.0001) ADG compared to those fed the negative control. A significant treatment × day interaction (P = 0.04) was observed for fecal Zn concentrations, where the level of Zn excreted in the feces was dependent on the sampling day in pigs fed a low level of ZnO or low level of microencapsulated ZnO. There was no evidence (P > 0.05) that small intestinal morphology differed significantly between treatments. In summary, feeding a microencapsulated form of ZnO did not alter piglet growth performance during the treatment period. Pigs fed a low level of ZnO or microencapsulated ZnO had reduced fecal Zn excretion by the end of the feeding period, but no significant impacts were observed on piglet small intestinal morphology.

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.

Summary of methodology used in enterotoxigenic Escherichia coli (ETEC) challenge experiments in weanling pigs and quantitative assessment of observed variability

Postweaning diarrhea in pigs is often caused by the F4 or F18 strains of enterotoxigenic Escherichia coli (ETEC). To evaluate interventions for ETEC, experimental infection via a challenge model is critical. Others have reviewed ETEC challenge studies, but there is a lack of explanation for the variability in responses observed. Our objective was to quantitatively summarize the responses and variability among ETEC challenge studies and develop a tool for sample size calculation. The most widely evaluated response criteria across ETEC challenge studies consist of growth performance, fecal consistency, immunoglobulins, pro-inflammatory cytokines, and small intestinal morphology. However, there is variation in the responses seen following ETEC infection as well as the variability within each response criteria. Contributing factors include the type of ETEC studied, dose and timing of inoculation, and the number of replications. Generally, a reduction in average daily gain and average daily feed intake are seen following ETEC challenge as well as a rapid increase in diarrhea. The magnitude of response in growth performance varies, and methodologies used to characterize fecal consistency are not standardized. Likewise, fecal bacterial shedding is a common indicator of ETEC infection, but the responses seen across the literature are not consistent due to differences in bacterial enumeration procedures. Emphasis should also be placed on the piglet's immune response to ETEC, which is commonly assessed by quantifying levels of immunoglobulins and pro-inflammatory cytokines. Again, there is variability in these responses across published work due to differences in the timing of sample collection, dose of ETEC pigs are challenged with, and laboratory practices. Small intestinal morphology is drastically altered following infection with ETEC and appears to be a less variable response criterion to evaluate. For each of these outcome variables, we have provided quantitative estimates of the responses seen across the literature as well as the variability within them. While there is a large degree of variability across ETEC challenge experiments, we have provided a quantitative summary of these studies and a Microsoft Excel-based tool was created to calculate sample sizes for future studies that can aid researchers in designing future work.

Investigation of the environmental presence of Salmonella spp. in finishing pigs at commercial swine farms in Kansas (United States)

Salmonellosis remains a major foodborne disease threat to public health worldwide. Swine are considered a reservoir for many Salmonella serotypes affecting humans; however, not all serotypes of concern in food animal products cause clinical signs of infection in swine. The objective of this study was to evaluate the presence and distribution of Salmonella spp. in finishing pigs at commercial farms across Kansas (USA). Five farms were selected and sampled when pigs weighed between 125-136 kilograms. Samples were collected and transported to the laboratory for processing following USDA-FSIS guidelines. Susceptibility and resistance profiles were also studied. Fifty-three % (100/186) of samples were culture positive for Enterobacteriaceae, and 14% (14/100) were confirmed Salmonella positive by PCR with 3 of 5 farms having no PCR-positive samples. S. Braenderup was the most common serovar identified in environmental samples, while S. Infantis, Agona, and Montevideo were identified in fecal samples. Multidrug resistance patterns were only found in Farm 3, in fecal samples and in one floor sample. The observations reported in this study highlight areas of concern, such as locations prone to fecal contamination, to be considered when cleaning and sanitizing between groups of pigs to decrease presence of Salmonella spp. in farm environments.

Multi-perspective region-based CNNs for vertebrae labeling in intraoperative long-length images

PURPOSE

Effective aggregation of intraoperative x-ray images that capture the patient anatomy from multiple view-angles has the potential to enable and improve automated image analysis that can be readily performed during surgery. We present multi-perspective region-based neural networks that leverage knowledge of the imaging geometry for automatic vertebrae labeling in Long-Film images - a novel tomographic imaging modality with an extended field-of-view for spine imaging.

METHOD

A multi-perspective network architecture was designed to exploit small view-angle disparities produced by a multi-slot collimator and consolidate information from overlapping image regions. A second network incorporates large view-angle disparities to jointly perform labeling on images from multiple views (viz., AP and lateral). A recurrent module incorporates contextual information and enforce anatomical order for the detected vertebrae. The three modules are combined to form the multi-view multi-slot (MVMS) network for labeling vertebrae using images from all available perspectives. The network was trained on images synthesized from 297 CT images and tested on 50 AP and 50 lateral Long-Film images acquired from 13 cadaveric specimens. Labeling performance of the multi-perspective networks was evaluated with respect to the number of vertebrae appearances and presence of surgical instrumentation.

RESULTS

The MVMS network achieved an F1 score of >96% and an average vertebral localization error of 3.3 mm, with 88.3% labeling accuracy on both AP and lateral images - (15.5% and 35.0% higher than conventional Faster R-CNN on AP and lateral views, respectively). Aggregation of multiple appearances of the same vertebra using the multi-slot network significantly improved the labeling accuracy (p < 0.05). Using the multi-view network, labeling accuracy on the more challenging lateral views was improved to the same level as that of the AP views. The approach demonstrated robustness to the presence of surgical instrumentation, commonly encountered in intraoperative images, and achieved comparable performance in images with and without instrumentation (88.9% vs. 91.2% labeling accuracy).

CONCLUSION

The MVMS network demonstrated effective multi-perspective aggregation, providing means for accurate, automated vertebrae labeling during spine surgery. The algorithms may be generalized to other imaging tasks and modalities that involve multiple views with view-angle disparities (e.g., bi-plane radiography). Predicted labels can help avoid adverse events during surgery (e.g., wrong-level surgery), establish correspondence with labels in preoperative modalities to facilitate image registration, and enable automated measurement of spinal alignment metrics for intraoperative assessment of spinal curvature.

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.

Detection and investigation of atypical porcine pestivirus in a swine production system

A commercial farrow-to-finish farm was suspicious of atypical porcine pestivirus (APPV) after observing clinical signs of congenital tremors (CT) and splay leg (SL) of newborn pigs. If introduced onto the farrow-to-finish, the two potential routes of introduction could be through replacement gilts or incoming semen doses. Therefore, this study aimed to determine the prevalence of clinical APPV within the sampled population, identify the route of APPV introduction to this system, and determine prevalence of detectable APPV RNA within a population of gilt multiplication farm offspring through an isolation nursery and finisher barn. Farrowing records were analyzed for the presence of CT or SL and corresponding parity of the dam. Overall, prevalence of clinically affected litters within batch farrowing groups ranged from 0 to 31%. Phylogenetic analysis was conducted on a serum sample from a gilt at the isolation nursery, semen dose for the farrow-to-finish farm, and serum of a CT piglet. Results indicated that the virus circulating in clinically affected piglets was most similar to an incoming semen dose (98.9% nucleotide identity). Blood samples were collected at four time points and revealed APPV clinical prevalence was 37.5–77.5% during the nursery phase and 0–26% during the finisher phase. Oral fluids were also collected during the finisher phase and APPV clinical prevalence was 100% for all sampling time points. In summary, introduction of APPV into naïve herds is associated with increased clinical CT and SL cases and is detectable in asymptomatic pigs during the nursery and finisher production phases. This study found that potential screening tests for APPV could include oral fluids or qRT-PCR analysis of semen doses especially when trying to identify prevalence levels on naïve farm.

Impact of storage conditions and premix type on water-soluble vitamin stability

Mitigation options to reduce the risk of foreign animal disease entry into the United States may lead to degradation of some vitamins. The objective of Exp. 1 was to determine the impact of 0, 30, 60, or 90 d storage time on water-soluble vitamin (riboflavin, niacin, pantothenic acid, and cobalamin) stability when vitamin premix (VP) and vitamin trace mineral premix (VTM) were blended with 1% inclusion of MCFA (1:1:1 blend of C6:C8:C10) or mineral oil (MO) with different environmental conditions. Samples stored at room temperature (approximately 22˚C) or in an environmentally-controlled chamber set at 40˚C and 75% humidity, high temperature high humidity (HTHH). The sample bags were pulled out at d 0, 30, 60 and 90 for room temperature (RT) condition and HTHH condition. Therefore, treatments were analyzed as a 2 × 2 × 2 × 3 factorial, with 2 premix types (vitamin premix vs VTM), 2 oil types (mineral oil, MO vs MCFA), 2 storage conditions (room temperature, RT vs high temperature and high humidity, HTHH) and 3 time points (d 30, 60, and 90).The objective of Exp. 2 was to determine the effect of heat pulse treatment and MCFA addition on water-soluble vitamin (riboflavin, niacin, pantothenic acid and cobalamin) stability with two premix types. A sample from each treatment was heated at 60°C and 20% humidity. Therefore, treatments were analyzed as a 2 × 2 factorial, with 2 premix types (VP vs VTM) and 2 oil types (MO vs MCFA). For Exp. 1, the following effects were significant for riboflavin: main effect of premix type (P &lt; 0.0001), storage condition (P = 0.015) and storage time (P &lt; 0.0001); for pantothenic acid: premix type × storage time × storage condition (P = 0.003) and premix type × oil type (P &lt; 0.0001) interactions; and for cobalamin: premix type × storage condition (P &lt; 0.0001) and storage time × storage condition (P &lt; 0.0001) interactions and main effect of oil type (P = 0.018). The results of Exp. 2 demonstrated that there was an interaction between oil type and premix type for only pantothenic acid (P = 0.021). The oil type did not affect the stability of riboflavin, niacin, or cobalamin and pantothenic acid stability was not different within similar premixes. The only difference in water-soluble vitamin stability between VP and VTM was for pantothenic acid (P &lt; 0.001). The results of this experiment demonstrated that the stability of water soluble vitamins are dependent on the vitamin of interest and the conditions at which it is stored.

Effects of formic acid and glycerol monolaurate on weanling pig growth performance, fecal consistency, fecal microbiota, and serum immunity

A total of 350 weanling pigs (DNA 400 × 200; initially, 5.67 ± 0.06 kg BW) were used in a 42-day study with 5 pigs per pen and 14 replicate pens per treatment. At weaning, pigs were allotted to pens in a completely randomized design and pens of pigs were randomly assigned to one of five dietary treatments: 1) negative control (CON; standard nursery diet containing only 150 ppm Zn from trace mineral premix and no acidifier); 2) control diet with 3,000 ppm added zinc from ZnO included in phase 1 and 2,000 ppm added zinc from ZnO included in phase 2 (ZnO); 3) control diet with 0.70% formic acid (FA; Amasil NA; BASF, Florham, NJ); 4) control diet with 0.18% glycerol monolaurate (GML; Natural Biologics GML, Natural Biologics, Newfield, NY); and 5) control diet with a 1.0% blend of formic acid and glycerol monolaurate (FORMI; FORMI 3G, ADDCON GmbH, Bitterfeld-Wolfen, Germany). Pigs were fed treatment diets from d 0 to d 28 and were then fed a common diet from d 28 to d 42. From days 0 to 7, pigs fed ZnO or FORMI had increased (P = 0.03) ADG compared to pigs fed CON, with no difference in feed intake (P > 0.05). Overall, pigs fed GML had reduced (P < 0.0001) ADG compared with those fed the CON, ZnO, or FORMI diets. Fecal DM was evaluated from days 7 to 28 and there was a treatment × day interaction (P = 0.04). Pigs fed GML had a lower fecal DM % on day 7, but a higher fecal DM % on days 14 and 21; however, no differences in fecal DM were observed on day 28. Fresh fecal samples were collected from the same randomly selected pig on days 0 and 14 (70 pigs total;14 pigs per treatment) for analysis of fecal microbial populations using 16S rDNA sequencing. Dietary treatment did not significantly impact fecal microbiota at the phyla level, but pigs fed ZnO had an increased relative abundance (P < 0.01) of the family Clostridiaceae. A blood sample was also collected from one pig per pen on days 0 and 14 for analysis of serum IgA, IgG, and TNF-α. There was no evidence that dietary treatment effected IgA, IgG, or TNF-α concentrations. The effect of sampling day was significant (P < 0.05), where circulating IgA and TNF-α was increased and IgG was decreased from days 0 to 14. In summary, there is potential for a blend of formic acid and GML to improve growth performance immediately post-weaning without negatively impacting fecal consistency. Formic acid and GML alone or in combination did not impact fecal microbial populations or serum immune parameters.

Developing a gateway program for importing non-animal origin ingredients from regions with African swine fever virus

The US Department of Agriculture (USDA) categorizes the risk of African swine fever virus (ASFV) entry into the United States through non-animal origin feed ingredients as 'negligible to moderate, with high uncertainty'. Both Canada and Australia have implemented policies that are suggested to reduce the risk of ASFV entry through feed ingredients, but the United States has not because of scientific limitations that have been addressed by recent publications. As regulators and industry consider a potential pathway forward, the objective of this manuscript is to describe a process to determine if a voluntary or regulatory import policy is warranted by the United States. Initially, the volume and types of non-animal origin feed ingredients imported from countries with ASFV were quantified and assigned a level of risk (high risk: unprocessed grains and oilseeds, moderate risk: soybean co-products (meals, oil, and oilcake), and low risk: amino acids, vitamins, and other synthetically produced products from countries that have ASFV). In 2020, moderate- and high-risk ingredients from ASFV-positive countries represented 3.1% of all ingredients imported into the United States. Policies from Canada and Australia were evaluated for practicality of implementation by US government officials. Industry representatives from both countries consistently stated their policies would not be feasible in the United States due to the differences in cost and complexity of the swine and feed industries. Overall, unprocessed, or high-risk, ingredients from ASFV-positive countries represent a low percentage of imported ingredients into the United States; however, cautionary procedures may still be warranted given industry demand.

Impacts of a post-transport/pre-processing rest period on the growth performance, anthelmintic efficacy, and serum metabolite changes in cattle entering a feed yard

A total of 80 crossbred, high-risk heifers (initially 250 ± 4.2 kg BW), were transported from an Oklahoma City, Oklahoma sale barn to the Kansas State University Beef Cattle Research Center. Cattle were unloaded and randomly placed into one of four receiving pens and provided ad libitum hay and water. Each pen was randomly assigned to one of the four rest times before processing: (1) immediately upon arrival (0); (2) after a 6-h rest period (6); (3) after a 24-h rest period (24); and (4) after a 48-h rest period (48). After all cattle were processed, heifers were allotted into individual pens with ad libitum access to a receiving ration and water. Heifers were weighed individually on d 0, 7, 14, 21, 28, and 35 to calculate average daily gain (ADG). Feed added and refusals were measured daily to determine dry matter intake (DMI). A fecal egg count reduction test and analysis of blood serum metabolites were also conducted. All data were analyzed using the GLIMMIX procedure of SAS (v. 9.4, Cary, NC) with individual animal as the experimental unit. Processing time did not impact (P > 0.05) heifer BW or ADG. From d 0 to 35, DMI decreased linearly (P = 0.027) as rest time increased. The number of days for heifers to reach a DMI of 2.5% BW was linearly increased (P = 0.023) as rest time increased. There was no evidence of differences (P ≥ 0.703) among rest times for feed efficiency. While morbidity did not differ between treatments (P > 0.10), mortality increased linearly (P = 0.026) as the time of rest increased. A significant processing time × day interaction (P < 0.0001) was observed for the prevalence of fecal parasites, where the percentage of positive samples was significantly lower 14-d after anthelmintic treatment, regardless of the processing time. Serum IBR titer for heifers processed at either 0 or 6-h upon arrival was significantly higher (P < 0.01) on d 35 compared to d 0. Heifers processed after a 48-h rest period had significantly higher glucose values (P < 0.01) on d 0 compared to heifers processed at 0, 6, or 24-h. In summary, rest time prior to processing did not impact receiving calf growth performance. A 6-h rest period upon arrival appeared to be most beneficial to DMI. Anthelmintic treatment at processing reduced the parasitic load in heifers processed at all times. Vaccine titer did not increase after initial processing in heifers processed 24- or 48-h after arrival, indicating the seroconversion of IBR antibodies during the longer rest period.

Joint synthesis and registration network for deformable MR-CBCT image registration for neurosurgical guidance

Objective.The accuracy of navigation in minimally invasive neurosurgery is often challenged by deep brain deformations (up to 10 mm due to egress of cerebrospinal fluid during neuroendoscopic approach). We propose a deep learning-based deformable registration method to address such deformations between preoperative MR and intraoperative CBCT.Approach.The registration method uses a joint image synthesis and registration network (denoted JSR) to simultaneously synthesize MR and CBCT images to the CT domain and perform CT domain registration using a multi-resolution pyramid. JSR was first trained using a simulated dataset (simulated CBCT and simulated deformations) and then refined on real clinical images via transfer learning. The performance of the multi-resolution JSR was compared to a single-resolution architecture as well as a series of alternative registration methods (symmetric normalization (SyN), VoxelMorph, and image synthesis-based registration methods).Main results.JSR achieved median Dice coefficient (DSC) of 0.69 in deep brain structures and median target registration error (TRE) of 1.94 mm in the simulation dataset, with improvement from single-resolution architecture (median DSC = 0.68 and median TRE = 2.14 mm). Additionally, JSR achieved superior registration compared to alternative methods-e.g. SyN (median DSC = 0.54, median TRE = 2.77 mm), VoxelMorph (median DSC = 0.52, median TRE = 2.66 mm) and provided registration runtime of less than 3 s. Similarly in the clinical dataset, JSR achieved median DSC = 0.72 and median TRE = 2.05 mm.Significance.The multi-resolution JSR network resolved deep brain deformations between MR and CBCT images with performance superior to other state-of-the-art methods. The accuracy and runtime support translation of the method to further clinical studies in high-precision neurosurgery.

Evaluating the impact of feeding dried distillers grains with solubles on Boer goat growth performance, meat color stability and antioxidant capacity

A total of 72 male Boer goat kids (21.7 ± 0.5 kg) were fed for 21 d with 3 kids per pen and 12 pens per treatment. Dietary treatments were: 0% inclusion of dried distillers grains with solubles (DDGS; 0% DDGS) or 33% DDGS inclusion (33% DDGS) and were provided ad libitum. Goats and feeders were weighed weekly to collect body weights (BW) and determine feed disappearance in order to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F). At the conclusion of the feeding study, a subset (n = 30; 2–3 goats from each pen representing six6 pens per treatment) of goats were harvested, carcasses evaluated, and loins were fabricated into 2.54 cm chops. Goat chop discoloration was evaluated by trained panelists and measured for L*, a*, and b* values on days 0, 4, 7, and 10 under retail display conditions. Samples were collected and analyzed for lipid oxidation, fatty acid profile, and hydrophilic and lipophilic antioxidant capacity. No evidence of differences was observed for final BW, ADFI, G:F, and carcass characteristics (P > 0.05). However, goats fed the 0% DDGS diet had greater ADG compared with those fed a diet containing 33% DDGS (P = 0.05). Overall, visual evaluation of discoloration, L*, a*, and b* as well as lipid oxidation data confirmed that feeding 33% DDGS to goats had no effect on goat chop discoloration and lipid oxidation (P > 0.10). However, all chops demonstrated a display effect, which they increased in visual discoloration and lipid oxidation and decreased in a* and b* values (P < 0.01) over the entirety of the 10-d period of retail display, regardless of the dietary treatments. As expected, feeding 33% DDGS to goats decreased relative percentage of multiple and total monounsaturated fatty acids, but increased relative percentage of multiple and total polyunsaturated fatty acids (PUFA; P < 0.05). The antioxidant capacity measurements showed no treatment difference in the hydrophilic portion (P > 0.10), but chops from the 33% DDGS treatment had greater lipophilic antioxidant activity compared with the 0% DDGS chops (P < 0.05). In conclusion, including 33% DDGS to the diet may negatively impact goat growth performance, but did not impact any carcass characteristics. Feeding a diet with 33% DDGS resulted in an increase in the PUFA content of goat chops but did not appear to impact meat color or lipid oxidation. The supposed negative consequence from increased PUFA is likely counterbalanced by the increased antioxidant capacity in the lipid component of meat, resulting in no difference in meat shelf-life.

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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PSI-9 Impacts of Formic Acid and Glycerol Monolaurate on Weanling Pig Immune Function

Feed additives such zinc oxide (ZnO) reduce post-weaning diarrhea and improve nursery pig growth performance, but there is regulatory pressure to eliminate their inclusion due to environmental concerns. Dietary acidifiers have been shown to positively impact gut health, immune status, and performance post-weaning. The objective of this experiment was to evaluate the effects of feeding formic acid and/or glycerol monolaurate (GML) on immune status of nursery pigs. A total of 350 weanling pigs (DNA 200 × 400; 5.7 ± 0.06 kg BW) were fed for 42 d with 5 pigs/pen and 14 pens/treatment. Pens were assigned in a completely randomized design to 1 of 5 diets: 1) Negative control (no additives); 2) Control + 3,000 ppm ZnO in phase 1 and 2,000 ppm ZnO in phase 2; 3) Control + 0.7% formic acid; 4) Control + 0.18% GML; 5) Control + 1.0% blend of formic acid and GML. Blood samples were collected via the jugular vein on d 0 and d 14 from 1 randomly selected pig per pen (14 pigs/treatment; 70 pigs total) for analysis of serum immunoglobulins (IgA, IgG) and tumor necrosis factor-α (TNF-α). After collection, samples were centrifuged at 2,000 x g for 10 min at 4°C and recovered serum was stored at -20°C until analysis. Using an ELISA kit, IgA, IgG and TNF- α were measured according to the kit manufacturer’s recommendations. Data were analyzed using the GLIMMIX procedure of SAS, with pig as the experimental unit. There was no evidence of differences (P &gt; 0.05) in serum IgA, IgG, or TNF-α as a result of dietary treatment. Sampling day significantly impacted (P &lt; 0.05) both serum IgA and IgG concentrations, where regardless of treatment, the levels of IgA increased from d 0 to 14 and decreased for IgG. In summary, feeding formic acid and/or GML did not impact serum immunoglobulin or cytokine levels. Further investigation into how these acidifiers effect immune function post-weaning is needed.

PSI-6 Evaluating Formic Acid and Glycerol Monolaurate Alone or in Combination on Weanling Pig Growth and Fecal Consistency

A total of 350 weanling pigs (DNA 200 x 400, initially 5.67 0.06 kg BW) were fed for 42 d in a completely randomized design. There were 5 pigs/pen and 14 pens/treatment. The 5 dietary treatments included: 1) nursery diet with no additives (CON), 2) control with 3,000 ppm ZnO in phase 1 and 2,000 ppm ZnO in phase 2 (ZnO); 3) control with 0.7% formic acid (Amasil NA, BASF; FA), 4) control with 0.18% glycerol monolaurate (Natural Biologics GML, Newfield, NY; GML), 5) control with a 1.0% blend of formic acid and GML (FORMI 3G, ADDCON GmbH, Bitterfeld-Wolfen, Germany; FORMI). Individual pig and feeder weights were collected weekly to determine average daily gain (ADG), average daily feed intake (ADFI), and gain to feed (G:F). From d 7 to d 35, fresh fecal samples (10 g) were collected weekly from the same 3 pigs per pen. Samples were dried in a 55 oven for 48 h to determine fecal DM %. In the first week post-weaning, pigs fed ZnO or FORMI 3G had increased (P = 0.03) ADG compared with pigs fed the control. From d 0 to d 42, pigs fed GML had reduced (P &lt; 0.0001) ADG compared with pigs fed the control, ZnO, or FORMI 3G. No evidence of differences (P &gt; 0.05) were observed for ADFI and G:F. For fecal DM, there was a significant treatment x day interaction (P = 0.04). Pigs fed GML had significantly less fecal DM % on d 7, but a higher fecal DM % on d 14 and 21. By d 28, fecal DM had standardized across dietary treatments. In summary, feeding FA and GML alone or together did not improve growth performance compared with a control during our experiment.

PSVIII-1 Evaluating the Efficacy of Acidifiers Used in Nursery Diets in Reducing Bacterial Loads in Both Non-Inoculated and Inoculated Complete Feed

Acidifiers are used in nursery pig diets to reduce the incidence of diarrhea, improve growth performance, and act as a feed preservative. The objective was to evaluate whether acidifiers were able to reduce bacteria presence in non-inoculated feed and reduce bacteria growth in feed inoculated with Escherichia coli and Enterococcus faecium. Each culture media was arranged in a 2×5 factorial with 2 phases and 5 diets. The diets were 1) control – no antibiotics, 2) ZnO (Phase 1: 3,000 ppm Zn and Phase 2: 2,000 ppm Zn), 3) formic acid at 0.7% of the diet (Amasil-NA; BASF Corp. Florham, NJ), 4) glycerol monolaurate – GML at 0.18% of the diet (Natural Biologics, Newfield, NY), and 5) FORMI-3G at 1.0% of the diet (Addcon Gmbh, Bitterfeld-Wolfen, Germany). Non-inoculated feed was plated onto Aerobic Count, E. coli/Coliform, and Enterobacteriaceae petrifilm (3M, St. Paul, MN). Inoculated feed was initially contaminated with E. coli or E. faecium and allowed to incubate prior to plating on MacConkey. There was no difference (P &gt; 0.05) in quantity of bacteria for the diets inoculated with E. coli. There was no difference (P &gt; 0.05) between the diets inoculated with E. faecium for phase 1; however, the formic acid diet had reduced (P &lt; 0.05) quantities of bacteria compared with control, ZnO, and GML diets. The control and ZnO phase 1 non-inoculated diets had reduced (P &lt; 0.05) quantities of aerobic bacteria, coliforms, and Enterobacteriaceae compared with GML. In phase 2 only the control had reduced (P &lt; 0.05) quantities of Enterobacteriaceae compared with the ZnO and formic acid diets. Formic acid was able to reduce E. faecium quantities in phase 2, while the control and ZnO had decreased overall bacterial loads in phase 1.

197 Effects of Sorghum Grain as a Replacement for Corn on Lamb Growth Performance, Economics, and Total Tract Digestibility

The objective of this experiment was to evaluate the effect of substituting grain sorghum in place of corn in growing lamb diets on their growth performance, nutrient digestibility, and economics. A total of 72 Rambouillet wethers (33.9 ± 3.10 kg) were utilized in a completely randomized design and allotted to 1 of 4 dietary treatments. Each pen contained 3 wethers , with 6 replicate pens per treatment. Dietary treatments included: 1) Control (basal diet with 0% inclusion of sorghum); 2) Sorg10(basal diet with 10% of corn substituted for sorghum); 3) Sorg20(basal diet with 20% of corn substituted for sorghum); and 4) Sorg30(basal diet with 30% of corn substituted for sorghum). Feed additions were recorded, and lamb and feeder weights were recorded weekly to determine average daily gain (ADG), average daily feed intake (ADFI) and gain to feed (G:F). Data were analyzed using the GLIMMIX procedure of SAS v9.4 (SAS Inst., Cary, NC) with pen as the experimental unit. There was no evidence that sorghum inclusion level affected ADG (P = 0.88), ADFI (P = 0.19), or G:F (P = 0.92). Due to the high price of sorghum, lambs fedSorg30 had greater (P &lt; 0.05) total feed cost per lamb, but there was no evidence of differences in cost/kg of gain (P = 0.63) or value of gain (P = 0.88). At the conclusion of the growth experiment, 24 of the initial 72 lambs (46.1 ± 3.9 kg) were fed an additional 14 d to evaluate total-tract digestibility of the 4 diets. Organic matter digestibility linearly increased (P &lt; 0.05) with sorghum inclusion. In conclusion, there was no evidence that feedings up to 30% sorghum in place of corn substantially affected lamb growth. Future research is necessary to investigate the efficiency of these diets.

61 Persistence and Distribution of African Swine Fever Virus in Feed and Feed Mill Environment Over Time After Manufacture of Experimentally Inoculated Feed and Subsequent Manufactured Batches of Feed

To reduce the risk of feed-based pathogens causing disease, some feed manufacturers quarantine high-risk ingredients before their inclusion in feed. Data exists that confirms this practice is effective, but there is no information about swine pathogen survival in mill environments. This objective of the study was to determine survival of African swine fever virus (ASFV) in swine feed and mill surfaces. A pilot-scale feed mill manufactured a batch of ASFV-free feed (Batch 1), followed by a batch inoculated with ASFV (5.6×104 TCID50/gram; Batch 2). Then 4 subsequent ASFV-free batches were manufactured (Batch 3-6). After each batch,10 feed samples were aseptically collected in a double ‘X’ pattern. During feed manufacturing, 24 steel coupons were placed on the floor of the manufacturing area and feed dust settled on them during the milling process and overnight. Feed samples and steel coupons were stored at room temperature. Three of each were randomly selected and analyzed for ASFV DNA on d 1, 3, 7, 14, 28, 60, 90, and 180. The interaction of batch and day impacted (P = 0.023) the number of genomic copies detected per gram of feed. There were no differences of genomic copies/g in early batches; but the quantity of detectable ASFV decreased with increasing storage time after collection. In Batches 4-6, the greatest quantity of ASFV was detected on d 1, but the lowest quantity was detected on d 7, 60, and 28 or 180 for Batches 5, 6, and 7, respectively. There was no evidence (P = 0.433) of ASFV degradation on environmental coupons over the 180-d storage period. This study found that quarantine time can help reduce, but not eliminate ASFV in feed over time. However, ASFV survives on feed manufacturing surfaces for at least 180 d. Additional research is necessary to evaluate the viability of detected virus to cause illness.

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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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PSI-4 Effects of Sorghum Inclusion in Lamb Diets on Apparent Total Tract Digestibility

The objective of this experiment was to evaluate the effect of grain sorghum inclusion on the apparent total tract digestibility of lamb diets. This experiment utilized 24 Rambouillet lambs (46.1 ± 3.90 kg) that were previously used in a growth experiment. Animals were housed in 1 of 24 pens with 1 lamb per pen and 6 pens per treatment. Lambs were randomly assigned 1 of the 4 treatment diets prior to the growth experiment and remained on the same treatment for over the 10-d experimental period. Treatments included 1) Control (0% sorghum inclusion); 2) Sorg10 (10% corn substituted for sorghum); 3) Sorg20 (20% corn substituted for sorghum); and 4) Sorg30 (30% corn substituted for corn). Diets were ground using hammermill and titanium dioxide was added to the ground diet at 0.4% as an indigestible marker. Lambs were fed these diets for 7-d prior to fecal sample collection to allow for steady-state marker concentrations. Fecal grab samples were collected every 6 hours over the final 3 d and were composited by animal to represent each 2-hour period of a 24-hour cycle. Feed and composited fecal samples were analyzed for crude fat, crude protein, ADF, NDF, and ash. Data were analyzed using the LM function in R with a fixed effect of treatment. Significance was defined at P &lt; 0.05 and means were separated using Tukey’s HSD where appropriate. Sorghum inclusion did not affect (P &gt; 0.16) crude protein, crude fat, or acid detergent fiber digestibility. Neutral detergent fiber digestibility was reduced (P = 0.02) for animals consuming Sorg20 and Sorg30 compared with the control, and Sorg10 was intermediate. Organic matter digestibility tended to decrease (P = 0.08) with increasing sorghum inclusion. In conclusion, replacing corn with sorghum at levels up to 30% had minimal impact on nutrient digestibility in growing lambs.

PSIV-5 Effects of Soybean Meal Addition to Increase Crude Protein in Growing Easycare Lamb Diets

A common industry practice is to substitute soybean meal (SBM) in place of corn for growing lambs in a feedlot setting, but there is limited data evaluating its impact, especially in hybrid hair sheep. The objective of this experiment was to evaluate the effect of increasing levels of crude protein (CP) by substituting SBM place of corn in growing Easycare lambs. A total of 77 Easycare (Dorper × Katahdin × Romanov) lambs were utilized in a completely randomized design with 7 replicate pens per treatment. Lambs (33 females; 26.3 ± 0.99 kg and 44 castrated males; 27.2 ± 0.95 kg) were fed for 28 d. The three dietary treatments included 1) Control (basal diet; 7.7% SBM and 11.0% CP); 2) SBM4 (4% SBM replacing corn in the basal diet; 11.7% SBM and 12.8% CP); and 3) SBM8 (8% SBM replacing corn in the basal diet; 15.7% SBM and 14.8% CP). Average daily gain (ADG), average daily feed intake (ADFI), gain to feed (G:F), and income over feed costs were determined. At the conclusion of the study, 15 castrated males were harvested to evaluate dietary impact on carcass characteristics. Data were analyzed using the GLIMMIX procedure of SAS v9.4 (SAS Inst., Cary, NC). Castrated males fed the control diet had reduced (P &lt; 0.05; 0.20 kg/d) ADG compared with those fed SBM4 or SBM8 (0.29 and 0.32 kg/d, respectively) or ewes consuming any diet (0.29 kg/d for all treatments). However, there was no evidence (P &gt; 0.05) that dietary treatment impacted final body weight, ADFI, G:F, income over feed cost, or measured carcass characteristics. These results suggest that growing Easycare castrated males benefit from 4% added SBM in place of corn to increase dietary CP, and that additional research is warranted to evaluate longer-term impacts on cost and carcass impacts.

Inoculation of Weaned Pigs by Feed, Water, and Airborne Transmission of Salmonella enterica Serotype 4,[5],12:i:

ABSTRACT

Salmonella enterica serotype 4,[5],12:i:- (STM) has become an increasing problem for food safety and has been often detected in swine products. Weanling pigs were exposed to STM-contaminated feed, water, or air to determine possible STM transmission routes. A control group of pigs was included. STM was monitored daily in feces and rectal and nasal swabs. STM colonization was most prevalent in tissues from tonsil, lower intestine, and mesenteric lymph nodes. No differences in lesion severity were observed between inoculated and control pigs. Contaminated feed, water, and aerosolized particles caused infection in weaned pigs; however, no STM colonization was observed in skeletal muscle destined for human consumption. Based on the results from this study, STM contamination in pork products most likely results from cross-contamination of meat by digesta or lymph node tissue during processing.

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Salmonella enterica 4,[5],12:i:-, an Emerging Threat for the Swine Feed and Pork Production Industry

ABSTRACT

Salmonella continues to be a significant cause of foodborne illnesses in human medicine. The Centers for Disease Control and Prevention reported Salmonella as the second leading cause of foodborne illness in the United States and the leading cause of both hospitalizations and deaths. Salmonella enterica 4,[5],12:i:- (STM) is a monophasic variant of Salmonella Typhimurium, and it is an emerging threat to both human and animal health. STM was first identified in the 1980s from poultry products and has become increasingly prevalent in meat products including pork. STM has also been identified in swine farms as well as in feed manufacturing environments and feed itself. Similar pulse-field gel electrophoresis profiles have been observed between human clinical cases and the STM samples originating from swine feed. These related profiles suggest a link between ingestion of contaminated feed by swine and the source of foodborne illness in human. The objective of this article was to better understand the history of STM and the possible pathway from swine feed to table. Continued research is necessary to better understand how STM can enter both the feed supply chain and the pork production chain to avoid contamination of pork products destined for human consumption.

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Effects of a dry acidulant addition to prevent Salmonella Contamination in Poultry Feed

Salmonella subs. serovar Enteritidis is a potential biological pathogen of concern in the poultry industry. Contamination of the bacterium on eggshells has led to human illnesses. With the implementation of new regulations, animal feed manufacturing continues to be under more stringent requirements. Specifically, there is zero tolerance for Salmonella Pullorum, Gallinarum, or Enteritidis in poultry feed. For this reason, it is important to determine an effective method of reducing or preventing Salmonella contamination in feed for poultry. Therefore, the objective of this study was to evaluate the impact of sodium bisulfate (SBS; Jones-Hamilton, Co., Walbridge, OH) added to poultry mash to reduce or prevent Salmonella growth over time. A single, commercially produced all-flock poultry mash was mixed with four different levels of SBS: 0.0%, 0.25%, 0.50%, and 0.70%. After SBS addition, the treated mash was inoculated with Salmonella enterica subsp, enterica serovar Enteritidis (ATCC 13076) and enumerated for Salmonella on days 0, 1, 2, 7, and 14 post-inoculation by plating on xylose lysine deoxycholate agar. There was no significant effect of SBS inclusion level on the reduction of Salmonella (P = 0.23); however, there was a significant effect of time across treatments (P < 0.0001). Additionally, there was no inclusion level × time interaction (P = 0.68). These results suggest that while SBS inclusion has no effect on Salmonella concentrations, storage time is effective at reducing or eliminating Salmonella contamination in poultry feed.

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.

Deformable MR-CT image registration using an unsupervised, dual-channel network for neurosurgical guidance

PURPOSE

The accuracy of minimally invasive, intracranial neurosurgery can be challenged by deformation of brain tissue - e.g., up to 10 mm due to egress of cerebrospinal fluid during neuroendoscopic approach. We report an unsupervised, deep learning-based registration framework to resolve such deformations between preoperative MR and intraoperative CT with fast runtime for neurosurgical guidance.

METHOD

The framework incorporates subnetworks for MR and CT image synthesis with a dual-channel registration subnetwork (with synthesis uncertainty providing spatially varying weights on the dual-channel loss) to estimate a diffeomorphic deformation field from both the MR and CT channels. An end-to-end training is proposed that jointly optimizes both the synthesis and registration subnetworks. The proposed framework was investigated using three datasets: (1) paired MR/CT with simulated deformations; (2) paired MR/CT with real deformations; and (3) a neurosurgery dataset with real deformation. Two state-of-the-art methods (Symmetric Normalization and VoxelMorph) were implemented as a basis of comparison, and variations in the proposed dual-channel network were investigated, including single-channel registration, fusion without uncertainty weighting, and conventional sequential training of the synthesis and registration subnetworks.

RESULTS

The proposed method achieved: (1) Dice coefficient = 0.82±0.07 and TRE = 1.2 ± 0.6 mm on paired MR/CT with simulated deformations; (2) Dice coefficient = 0.83 ± 0.07 and TRE = 1.4 ± 0.7 mm on paired MR/CT with real deformations; and (3) Dice = 0.79 ± 0.13 and TRE = 1.6 ± 1.0 mm on the neurosurgery dataset with real deformations. The dual-channel registration with uncertainty weighting demonstrated superior performance (e.g., TRE = 1.2 ± 0.6 mm) compared to single-channel registration (TRE = 1.6 ± 1.0 mm, p < 0.05 for CT channel and TRE = 1.3 ± 0.7 mm for MR channel) and dual-channel registration without uncertainty weighting (TRE = 1.4 ± 0.8 mm, p < 0.05). End-to-end training of the synthesis and registration subnetworks also improved performance compared to the conventional sequential training strategy (TRE = 1.3 ± 0.6 mm). Registration runtime with the proposed network was ∼3 s.

CONCLUSION

The deformable registration framework based on dual-channel MR/CT registration with spatially varying weights and end-to-end training achieved geometric accuracy and runtime that was superior to state-of-the-art baseline methods and various ablations of the proposed network. The accuracy and runtime of the method may be compatible with the requirements of high-precision neurosurgery.

Deformable 3D-2D registration for high-precision guidance and verification of neuroelectrode placement

Purpose.Accurate neuroelectrode placement is essential to effective monitoring or stimulation of neurosurgery targets. This work presents and evaluates a method that combines deep learning and model-based deformable 3D-2D registration to guide and verify neuroelectrode placement using intraoperative imaging.Methods.The registration method consists of three stages: (1) detection of neuroelectrodes in a pair of fluoroscopy images using a deep learning approach; (2) determination of correspondence and initial 3D localization among neuroelectrode detections in the two projection images; and (3) deformable 3D-2D registration of neuroelectrodes according to a physical device model. The method was evaluated in phantom, cadaver, and clinical studies in terms of (a) the accuracy of neuroelectrode registration and (b) the quality of metal artifact reduction (MAR) in cone-beam CT (CBCT) in which the deformably registered neuroelectrode models are taken as input to the MAR.Results.The combined deep learning and model-based deformable 3D-2D registration approach achieved 0.2 ± 0.1 mm accuracy in cadaver studies and 0.6 ± 0.3 mm accuracy in clinical studies. The detection network and 3D correspondence provided initialization of 3D-2D registration within 2 mm, which facilitated end-to-end registration runtime within 10 s. Metal artifacts, quantified as the standard deviation in voxel values in tissue adjacent to neuroelectrodes, were reduced by 72% in phantom studies and by 60% in first clinical studies.Conclusions.The method combines the speed and generalizability of deep learning (for initialization) with the precision and reliability of physical model-based registration to achieve accurate deformable 3D-2D registration and MAR in functional neurosurgery. Accurate 3D-2D guidance from fluoroscopy could overcome limitations associated with deformation in conventional navigation, and improved MAR could improve CBCT verification of neuroelectrode placement.

Sampling and detection of African swine fever virus within a feed manufacturing and swine production system

Transmission of biological hazards capable of causing disease in livestock can occur through a wide variety of direct and indirect routes. In swine production, there are a large number of possible routes of exposure of a pathogen into a susceptible population. African swine fever virus (ASFV) has been a significant challenge for Southeast Asia since first detected in China in 2018 and has spread through many countries within the region. In order to understand potential transmission pathways within an ASFV endemic region, a diagnostic investigation was performed to determine the level of contamination on a wide variety of surface types within a live animal production, feed manufacturing, and feed distribution system located in Vietnam. All diagnostic testing was performed locally by the production system's internal diagnostic laboratory using real‐time polymerase chain reaction (rt‐PCR) analysis. Early in the diagnostic investigation, it became clear that feed trucks were a common site of ASFV surface contamination detection. This information resulted in biosecurity‐focused actions for feed trucks arriving back at the feed mill, including decontamination of interior truck cab surfaces and washing of exterior truck surfaces with high‐pressure water prior to application of surface disinfectants. Additionally, a low number of rt‐PCR positive samples were detected within the feed production system, with the greatest number coming from transient surfaces such as high traffic areas and worker clothing. This illustrates the importance of managing employee traffic through procedures such as zoning and separation between clean–dirty areas to reduce the likelihood of pathogen transmission. In conclusion, this report illustrates the importance of routine data capture regarding efficacy of biosecurity procedures which allows for real‐time updates and improvement as biosecurity gaps are identified.

Effect of cleaning corn on mycotoxin concentration and nursery pig growth performance

Mycotoxins are naturally produced hazards that result from molds grown on cereal grains and other commodities. These molds may produce carcinogenic mycotoxins, which can be harmful to humans and animals. Removing broken kernels has been demonstrated to reduce mycotoxin concentration, but with high variability. Therefore, two experiments were conducted to quantify the magnitude of natural mycotoxin concentration that may be reduced by cleaning corn. Two loads of corn that were naturally contaminated with mycotoxins were procured. Corn for Experiment 1 was contaminated with aflatoxin (1,074 parts per billion; ppb), fumonisin (8.3 parts per million; ppm), and ochratoxin A (206 ppb), while corn for Experiment 2 was contaminated with only fumonisin (5.5 ppm). Corn was cleaned by mechanical sieving. For each experiment, corn was divided into twenty 150 kg runs. Runs were randomly assigned to 1 of 4 experimental treatments: 1) no screen 2) 12.7 mm screen, 3) 4.8 mm screen, and 4) 12.7 + 4.8-mm screen. The corn cleaner was sanitized between runs. Three 5 kg corn samples were collected from each run, and analyzed for mycotoxin concentration. In Experiment 1, cleaning reduced (P < 0.05) aflatoxin and fumonisin concentration by an average of 26% and 45%, respectively, compared to the original uncleaned corn level, but did not impact (P > 0.10) ochratoxin A. The resultant screenings had nearly four times the aflatoxin (4,224 ppb) and 7.5 times the fumonisin concentration (60.4 ppm) as the uncleaned corn. In Experiment 2, cleaning reduced (P < 0.05) fumonisin concentration by 32%. The resultant screenings had 19.6 times the fumonisin concentration (65.4 ppm) as the uncleaned corn. To determine the effect that cleaning corn may have on nursery pig growth performance, 360 nursery pigs were used in Experiment 3 to evaluate the impact of cleaning or pelleting on growth performance. Treatments were arranged in a 2 × 3 factorial with corn type (uncleaned vs. cleaned) and feed form (mash vs. pelleted from either mill A or B). Neither cleaning corn nor pellet mill type affected (P > 0.19) nursery pig growth performance. Pelleting improved (P < 0.0001) gain to feed ratio (G:F) by 7.6% compared to mash diets. These data suggest that cleaning is an effective method to legally reduce aflatoxin and fumonisin concentration, but does not impact animal growth performance. Screenings should be used cautiously when feeding to animals.

Palatability Traits of Sirloin Cap Steaks From Four USDA Quality Grades

Sirloin cap steaks from 4 different USDA quality grades were evaluated to determine the effect of marbling on eating experience. Top sirloin cap steaks (N = 60) of 4 different quality grades (Prime, Top Choice, Low Choice, and Select) were evaluated in the current study. Top sirloin butts were collected, and the biceps femoris was removed, trimmed, and sliced into twelve 2.54-cm-thick steaks. The steaks from each subprimal were aged for 28 d and designated for either trained sensory panels, consumer sensory panels, Warner-Bratzler shear force, or moisture and fat determination. The Prime steaks were rated the highest (P &lt; 0.05) for overall liking and were higher (P &lt; 0.05) for flavor liking than Low Choice and Select steaks within the consumer panels. However, all quality treatments were similar (P &gt; 0.05) in juiciness and tenderness for the consumer panels. Additionally, a similar (P &gt; 0.05) percentage of samples from each treatment were rated acceptable for tenderness, juiciness, flavor liking, and overall liking, with each trait having greater than 70% of samples rated acceptable. Also, Prime steaks were rated the highest (P &lt; 0.05) for sustained juiciness and overall tenderness within the trained sensory panels. Similarly, Prime steaks were rated higher (P &lt;0.05) for initial juiciness than the Low Choice and Select treatments but were similar (P &gt; 0.05) to Top Choice. These results indicate that USDA quality grades impact the eating quality of sirloin cap steaks, especially within the Prime grade, and could provide an opportunity for refined marketing and added economic value for the cut.

Using environmental sampling to evaluate the effectiveness of decontamination methods to reduce detection of porcine epidemic diarrhea virus RNA on feed manufacturing surfaces

Porcine epidemic diarrhea virus (PEDV) is a possible biological hazard in feed mills. If the virus enters a feed mill, it becomes widely distributed and is difficult to decontaminate from both feed contact and non-feed contact surfaces. The objective of this study was to evaluate a variety of liquid and dry decontamination treatments that could be used to reduce the amount of PEDV found on feed manufacturing surfaces. This experiment was designed as a 5 × 10 factorial with five different feed manufacturing surfaces and 10 decontamination treatments with three replicates of each combination. Surfaces included stainless steel, solid polyethylene, woven polypropylene tote bag, rubber, and sealed concrete coupons. One mL (1×10⁵ TCID₅₀/mL) of stock PEDV was applied to each surface and allowed to dry completely for 60 min. Next, for decontamination requiring surface application, the application was performed and allowed 15 min contact time. The quantity of PEDV RNA was determined using quantitative reverse transcription PCR. A decontamination treatment × surface interaction was observed (P < 0.0001), indicating the efficacy of treatment is dependent upon the surface in which it is applied. Within the cement surfaces, the sodium hypochlorite resulted in the greatest (P < 0.05) cycle threshold (Ct) value, followed by formaldehyde which had a greater (P < 0.05) Ct value compared to remaining treatments. Within polyethylene, rubber, and stainless steel surfaces, the formaldehyde treated surfaces had the greatest Ct values (P < 0.05), followed by the sodium hypochlorite treatment, with other treatments all having lower Ct values (P < 0.05). For the woven polyethylene surfaces, the formaldehyde and sodium hypochlorite treatments had greater Ct values compared to all other treatments (P < 0.05). Additional research is necessary to identify the role of decontamination treatment on PEDV infectivity and develop methods for decontamination of feed manufacturing facilities.

Sodium buffered formic acid concentration and feed pH is stable over a 3-month period

Promoting feed hygiene with organic acids is an effective method to prevent foodborne illnesses from bacterial infection. The stability and acidification of mash and pelleted feed with sodium buffered formic acid was investigated. The acid product was incorporated to reach total formate inclusion levels of 0, 6, or 12 g/kg for swine nursery feed; 0, 4, or 9 g/kg for swine finishing feed; and 0, 3, or 6 g/kg for broiler grower feed. Samples were analyzed for total formate and pH on d 4, 32, 60, or 88 post-manufacturing. The concentration of formate remained stable across an 88-d period (P < 0.01). Treatment with the formic acid product decreased feed pH with increasing inclusion levels (all P < 0.01). Within each inclusion level of acid and across time, pH tended to increase in pelleted feed and decrease in mash feeds (all P < 0.01); however, these changes were small (0.1 units pH). These data suggest that sodium buffered formic acid can be applied to both mash and pelleted feed to provide continuous acidification over a 3-month period.

3D vertebrae labeling in spine CT: an accurate, memory-efficient (Ortho2D) framework

Purpose.Accurate localization and labeling of vertebrae in computed tomography (CT) is an important step toward more quantitative, automated diagnostic analysis and surgical planning. In this paper, we present a framework (called Ortho2D) for vertebral labeling in CT in a manner that is accurate and memory-efficient.Methods. Ortho2D uses two independent faster R-convolutional neural network networks to detect and classify vertebrae in orthogonal (sagittal and coronal) CT slices. The 2D detections are clustered in 3D to localize vertebrae centroids in the volumetric CT and classify the region (cervical, thoracic, lumbar, or sacral) and vertebral level. A post-process sorting method incorporates the confidence in network output to refine classifications and reduce outliers. Ortho2D was evaluated on a publicly available dataset containing 302 normal and pathological spine CT images with and without surgical instrumentation. Labeling accuracy and memory requirements were assessed in comparison to other recently reported methods. The memory efficiency of Ortho2D permitted extension to high-resolution CT to investigate the potential for further boosts to labeling performance.Results. Ortho2D achieved overall vertebrae detection accuracy of 97.1%, region identification accuracy of 94.3%, and individual vertebral level identification accuracy of 91.0%. The framework achieved 95.8% and 83.6% level identification accuracy in images without and with surgical instrumentation, respectively. Ortho2D met or exceeded the performance of previously reported 2D and 3D labeling methods and reduced memory consumption by a factor of ∼50 (at 1 mm voxel size) compared to a 3D U-Net, allowing extension to higher resolution datasets than normally afforded. The accuracy of level identification increased from 80.1% (for standard/low resolution CT) to 95.1% (for high-resolution CT).Conclusions. The Ortho2D method achieved vertebrae labeling performance that is comparable to other recently reported methods with significant reduction in memory consumption, permitting further performance boosts via application to high-resolution CT.

Effect of mixing and feed batch sequencing on the prevalence and distribution of African swine fever virus in swine feed

It is critical to have methods that can detect and mitigate the risk of African swine fever virus (ASFV) in potentially contaminated feed or ingredients bound for the United States. The purpose of this work was to evaluate feed batch sequencing as a mitigation technique for ASFV contamination in a feed mill, and to determine if a feed sampling method could identify ASFV following experimental inoculation. Batches of feed were manufactured in a BSL-3Ag room at Kansas State University's Biosafety Research Institute in Manhattan, Kansas. First, the pilot feed manufacturing system mixed, conveyed, and discharged an ASFV-free diet. Next, a diet was manufactured using the same equipment, but contained feed inoculated with ASFV for final concentration of 5.6 × 10⁴ TCID₅₀ /g. Then, four subsequent ASFV-free batches of feed were manufactured. After discharging each batch into a collection container, 10 samples were collected in a double 'X' pattern. Samples were analysed using a qPCR assay for ASFV p72 gene then the cycle threshold (Ct) and Log₁₀ genomic copy number (CN)/g of feed were determined. The qPCR Ct values (p < .0001) and the Log₁₀ genomic CN/g (p < .0001) content of feed samples were impacted based on the batch of feed. Feed samples obtained after manufacturing the ASFV-contaminated diet contained the greatest amounts of ASFV p72 DNA across all criteria (p < .05). Quantity of ASFV p72 DNA decreased sequentially as additional batches of feed were manufactured, but was still detectable after batch sequence 4. This subsampling method was able to identify ASFV genetic material in feed samples using p72 qPCR. In summary, sequencing batches of feed decreases concentration of ASFV contamination in feed, but does not eliminate it. Bulk ingredients can be accurately evaluated for ASFV contamination by collecting 10 subsamples using the sampling method described herein. Future research is needed to evaluate if different mitigation techniques can reduce ASFV feed contamination.

PSI-5 Effects of Bacillus and Lactobacillus in Milk Replacer on Calf Health

Stress in pre-ruminant calves can impact the functionality of the gastric epithelial lining, thereby impacting calf health during times of stress and potentially later in life. To mitigate this challenge, milk replacers frequently contain antibiotics to reduce the proliferation of harmful bacteria that may result in disease in pre-ruminant, milk supplemented calves. However, there is consumer and regulatory pressure to reduce the reliance on these antimicrobials and evaluate alternatives, such as probiotics, that may shift gut bacterial populations without impacting potential antimicrobial resistance. The objective of this study was to determine if supplementing calves with Lactobacillus and Bacillus species in milk replacer impacts pre-ruminant calf health. The project included 44 calves (50% Angus/50% Holstein) in a randomized complete block design, with calf serving as the experimental unit and age serving as a blocking factor. Calves were fed twice daily one of two treatments: 1) milk replacer with Lactobacillus and two Bacillus species at a total rate of 1.25 x 10^9 cfu/head/day; or 2) non-treated milk replacer. There were 22 replicates per treatment. To determine health status, calves were scored daily based on health indicators for fecal consistency or eye, nose, or ear normality. Health scores were ranked from 0 to 3, with 0 representing normal and 3 signaling severe symptoms, such as bilateral eye or nasal discharge, ear droop, or watery feces. Statistical analysis was performed using the GLIMMIX procedure of SAS. Overall, there was no evidence (P &gt; 0.05) that Lactobacillus and Bacillus inclusion impacted any measured health parameter. Notably, approximately 50% of calves had fecal scores indicating some level of watery stool, but this was not impacted (P &gt; 0.05) by probiotics. In summary, the inclusion of probiotics in calf milk replacer did not appear to impact calf health in the first 30 days.

PSVI-4 Efficacy of Medium Chain Fatty Acids and Fatty Acid-based Feed Additives as a Mitigation Strategy Against Porcine Epidemic Diarrhea Virus and Porcine Reproductive and Respiratory Syndrome Virus

Recent research has demonstrated that swine viruses can be transmitted via feed. Chemical feed additives have been suggested for the mitigation of these viruses in complete feed. Therefore, the objective of this study was to evaluate the efficacy of a commercially available formaldehyde-based feed additive, medium chain fatty acid blend (MCFA), and commercially available fatty acid-based products for mitigation of porcine epidemic diarrhea virus (PEDV) and porcine reproductive and respiratory syndrome virus (PRRSV) in a feed matrix. Treatments consisted of: 1) non-treated positive control, 2) 0.33% commercial formaldehyde-based product (Sal Curb; Kemin Industries, Inc.; Des Moines, IA), 3) 0.5% MCFA blend (1:1:1 ratio of C6:0, C8:0, and C10:0, Sigma Aldrich, St. Louis, MO), 4) 0.25%, 5) 0.5%, or 6) 1% of commercial dry mono and diglyceride-based product (Furst Strike; Furst-McNess Company, Freeport, IL), 7) 0.25%, 8) 0.5%, or 9) 1% of commercial dry mono and diglyceride-based product (Furst Protect; Furst-McNess Company, Freeport, IL), 10) 0.25%, 11) 0.5%, or 12) 1% dry mono and diglyceride-based experimental product (Furst-McNess Company, Freeport, IL) with 3 replications/treatment. Treatments were applied to complete swine feed before inoculation with 106 TCID50/g of feed with PEDV or PRRSV. Post inoculation feed was held at ambient temperature for 24 h before being analyzed via qRT-PCR. The analyzed values represent the cycle threshold. Formaldehyde and MCFA decreased (P &lt; 0.05) the detectable RNA of PEDV and PRRSV compared to all other treatments. Furst Strike, Furst Protect, and the experimental product did not significantly impact detectability of PEDV or PRRSV RNA. In conclusion, MCFA and formaldehyde treatments are effective at reducing detection of RNA from PEDV and PRRSV in feed.

PSIV-4 The Impacts of Feeding Corn Co-products and Ionophores to Growing Boer Goats

Two experiments were conducted to evaluate corn dried distiller’s grains with solubles (DDGS) and corn gluten feed (CGF) as replacements for soybean meal (SBM) and determine the impact of an ionophore on Boer goat growth performance and carcass characteristics. In Exp. 1, 75 Boer-goat kids (initial BW 26.9 ± kg) were allotted to one of 5 dietary treatments: 1) Negative control (100% SBM, 0% DDGS and 0% CGF; 100SBM); 2) Positive control (100% DDGS, 0% CGF and 0% SBM; 100DDGS); 3) 66% DDGS, 33% CGF and 0% SBM (66DDGS/33CGF); 4) 66% CGF, 33% DDGS and 0% SBM (33DDGS/66 CGF); and 5) 100% CGF, 0% DDGS and 0% SBM (0DDGS/100CGF). Dietary treatment did not impact (P ≤ 0.21) growth. In Exp. 2, 72 Boer-goat kids (initial BW 21.7 ± kg) were allotted to one of 4 dietary treatments in a 2 X 2 factorial with 2 protein sources and 2 ionophore inclusions: 1) SBM/no ionophore (SBM-NI); Diet 2) SBM with ionophore (SBM-I); Diet 3) DDGS/no ionophore (DDGS-NI); and Diet 4) DDGS with ionophore (DDGS-I). On d 21, goats were split into 2 groups according to their protein source and fed an additional d 10 (Group 1: DDGS-I; Group 2: SBM-I). The 15 heaviest goats from each group were harvested and carcass data collected. The protein source X ionophore interaction was not significant (P ≥ 0.15) for any measured response criteria. Goats fed a diet with SBM had significantly increased (P = 0.04) ADG compared to goats fed DDGS. No evidence of difference was observed (P ³ 0.10) for ADFI or G:F. Dietary treatment did not impact (P &gt; 0.05) carcass characteristics. In summary, these data suggest that corn co-products can be economically included in Boer-goat diets, however their impact on growth performance is variable compared to that of soybean meal.

47 Effects of Lactobacillus and Bacillus Probiotics on Pre-ruminating Calf Growth Performance and Efficiency

Lactobacillus and Bacillus probiotics may serve as an alternative to antibiotics in milk replacer for pre-ruminant calves by altering gastrointestinal microflora to prevent the proliferation of harmful bacteria. However, there are limited studies evaluating their impact on calf growth and efficiency. The objective of this trial was to discover the impact of probiotic-containing milk replacer on pre-ruminating calf growth performance. A total of 44 pre-ruminant calves (50% Angus/50% Holstein, average weight 39.3 kg + 7.5 kg) were fed milk replacer with either no probiotic or 1.25x10^9 colony forming units/head/day of a probiotic blending containing Lactobacillus and two different Bacillus species (Church & Dwight Animal Nutrition (Princeton, NJ). Calves were blocked by age and randomly assigned within block to one of two treatments in a randomized complete block design. Calf was the experimental unit, with 22 calves per treatment. Calf weight and hip height was measured on d 0 and 30 to calculate average daily gain (ADG) and average growth per day. Calves were offered 1.36 kg milk replacer [15% dry matter (DM)] twice daily and up to 0.5 kg starter feed (88% DM) once daily. Refusals were recorded to calculate average daily intake and gain to feed ratio (G:F). Initial weight differed (P = 0.020) between treatments, and was therefore used as a covariate in all response criteria. Calves fed milk replacer with probiotic had greater (P &lt; 0.05) ADG (0.53 vs. 0.42 kg/d, respectively) and G:F (0.50 vs. 0.41, respectively) than those fed the control. There was no evidence (P &gt;0.05) that probiotic inclusion impacted hip height on d 30 or daily intake. In summary, Lactobacillus and Bacillus probiotic inclusion in milk replacer improved calf growth performance without impacting intake. Subsequent research is warranted to elucidate mode of action and evaluate impact relative to an antibiotic-containing positive control.

185 The Impacts of Commercial Dietary Acidifiers on Growth Performance of Nursery Pigs

A total of 360 weanling pigs (DNA 200 x 400; initially 9.7 ± 0.23 kg BW) were used in a 21-d growth trial to evaluate the effects of commercial diet acidifiers in nursery diets. Upon weaning, pigs were weighed and allotted to pens (6 pigs/pen, 10 replicate pens/treatment, blocked by 2 separate nursery rooms) and pens were then randomly assigned to one of 6 treatment diets: 1) negative control (no antibiotics or acidifiers) and the control with 2) 0.25% Acidifier A (KEM-GEST™, Kemin Industries, Des Moines, IA); 3) 0.3% Acidifier B (ACITVATE® DA, Novus International, Saint Charles, MO); 4) 0.5% Acidifier C (OutPace®, PMI Additives, Arden Hills, MN); 5) 50 g/ton carbadox; 6) 400 g/ton chlortetracycline. Pigs were fed common phase 1 and phase 2 starter diets without antimicrobials for 21 days, then fed experimental diets for 21 days. Data were analyzed as a completely randomized block design with pen as the experimental unit. Dietary treatment significantly impacted (P &lt; 0.05) all growth response criteria for each week of the experiment. Overall (d 0 to 21), ADG was the greatest (P &lt; 0.0001) for pigs fed a diet containing CTC. Likewise, ADFI was increased (P &lt; 0.0001) for pigs consuming CTC compared to those fed the negative control, acidifier A, acidifier B and carbadox diets, while those fed acidifier C were intermediate. Feed efficiency was poorest (P &lt; 0.0001) in pigs fed a diet with carbadox. By the end of the experiment, pigs fed CTC were significantly heavier (P &lt; 0.0001) than pigs fed all remaining treatments. In summary, feeding CTC improved nursery pig performance while carbadox unexpectedly reduced it. The addition of dietary acidifiers did not improve growth performance compared to a negative control.

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PSIII-15 Effect of the Pelleting Process on Diet Formulations with Varying Levels of Crystalline AA and Reducing Sugars on Nursery Pig Growth Performance

A total of 360 pigs (DNA 200×400; initially 11.3 kg) were used in an 18-d study to determine the effect of pelleting diets with or without increased concentrations of free amino acids (AA) and reducing sugars (RS) on pig growth performance. There were 9 replications/treatment and 5 pigs/pen. Treatments were arranged in a 2×2×2 factorial with main effects of diet form (mash vs. pellet), crystalline AA (low vs. high), and RS (low vs. high) provided by dried distillers grain with solubles and bakery meal included at 20% and 15%, respectively. Diets were pelleted to achieve a conditioning temperature of 86.7°C using a 22.4 kW pellet mill equipped with a 4.7 x 34.9-mm die. Data were analyzed as a CRD using the GLIMMIX procedure of SAS. There were no 3-way interactions observed. For the main effect of feed form, ADFI decreased (P=0.001) and G:F and caloric efficiency improved (P=0.001) in pigs fed pelleted diets compared to mash diets. For the main effect of crystalline AA, pigs fed diets with high crystalline AA had increased (P&lt; 0.024) ADFI compared to those fed diets with low crystalline AA. For the main effect of RS, pigs fed high RS diets had decreased (P&lt; 0.041) ADG, ADFI, G:F, and caloric efficiency compared to those fed low RS. In conclusion, there was no evidence of interactions between treatments, indicating that increasing amounts of crystalline AA and RS did not influence the response to pelleted diets. Pigs fed the high RS diets had reduced feed intake which resulted in reduced gain and improved feed and caloric efficiency.

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199 Effect of the Pelleting Process on Diet Formulations with Varying Levels of Crystalline Amino Acids and Reducing Sugars on Digestibility in Growing Pigs

The objective of this study was to determine effects of pelleting on the standardized ileal digestibility (SID) of amino acids (AA) in diets with or without increased concentrations of free AA and reducing sugars (RS). Eight individually housed, ileal cannulated barrows (initially 69.2 kg) were allotted to a replicated 8×8 Latin square with 8 diets and eight 7-d periods with ileal digesta collected on d 6 and 7. Treatments were arranged in a 2×2×2 factorial with main effects of diet form (mash vs. pellet), crystalline AA (low vs. high), or reducing sugars (low vs. high) provided by dried distillers grains with solubles and bakery meal. Diets were pelleted to achieve a hot pellet temperature of 85 to 88°C. Data were analyzed as a completely randomized Latin square using the GLIMMIX procedure of SAS. A feed form×RS interaction (P &lt; 0.026) for SID of tryptophan was observed. Feeding pelleted low RS diets improved SID of tryptophan compared with mash high and low RS diets, and pelleted high RS diets. For main effects of feed form, the SID of total AA, CP, and indispensable AA increased (P &lt; 0.042) in pigs fed pelleted diets compared with mash diets. For main effects of crystalline AA, pigs fed high crystalline AA had increased (P = 0.007) SID of tryptophan and decreased (P = 0.050) SID of histidine compared with those fed low crystalline AA diets. For main effects of RS diets, pigs fed high RS diets had decreased (P &lt; 0.05) SID of total AA, CP and indispensable AA. In conclusion, pelleting diets with increased crystalline AA or RS did not affect the improvement in AA digestibility from pelleting. Pelleting diets improved AA digestibility. Diets formulated with high crystalline AA had increased SID of tryptophan. Formulating diets with high RS resulted in decreased AA digestibility compared with corn-soybean meal-based diets.

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PSVI-7 Evaluation of Feed Mitigant Efficacy for Control of Porcine Epidemic Diarrhea Virus and Porcine Reproductive and Respiratory Syndrome Virus When Inoculated Either Alone or Together

Research has demonstrated that swine feed can be a fomite for viral transmission and certain feed additives can effectively reduce viral contamination. However, additional information is needed to evaluate the efficacy of additives when feed is inoculated with more than one virus. The objective of this study was to evaluate the efficacy of two feed additives for mitigation of porcine epidemic diarrhea virus (PEDV) and porcine reproductive and respiratory syndrome virus (PRRSV) when inoculated individually or together. Feed additives included: 1) no treatment, 2) 0.33% commercial formaldehyde-based product (Sal Curb, Kemin Industries, Des Moines, IA), and 3) 0.50% medium chain fatty acids blend (MCFA; 1:1:1 ratio of C6:C8:C10, Sigma Aldrich, St. Louis, MO). Samples were inoculated with PEDV and PRRSV alone or together at an inoculation concentration of 106 TCID50/g for all viruses. Once inoculated, feed was stored at ambient temperature for 24-h before analyzed via qRT-PCR. For samples inoculated with PEDV or PRRSV alone, a qRT-PCR assay was used which was designed to detect PEDV or PRRSV nucleic acid. For co-inoculated samples, an assay was designed to independently detect both PEDV and PRRSV within a single reaction. For PEDV alone, there was marginally significant evidence that feed additives resulted in differences in cycle threshold (Ct) value (P = 0.052), but no evidence was observed for pairwise differences. For PRRSV alone, formaldehyde increased Ct compared to the untreated control and MCFA treatment (P &lt; 0.05). For co-infection of PRRSV and PEDV, MCFA and formaldehyde increased Ct (P &lt; 0.05) in comparison to non-treated feed. In summary, formaldehyde increased Ct values in feed when contaminated with PRRSV while both mitigants increased Ct value in feed when co-inoculated with PRRSV and PEDV.

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Evaluating dietary acidifiers as alternatives for conventional feed-based antibiotics in nursery pig diets

A total of 360 weanling pigs (DNA 200 × 400; initially 9.7 ± 0.23 kg BW) were used in a 21-d experiment with 6 pigs/pen, 10 replicate pens/treatment, and 2 separate nursery rooms, each with 30 pens. Pigs were weighed and allotted to pens based on BW in a completely randomized block design to one of six treatment diets: 1) Negative control (no organic acids or antibiotics) and the control with 2) 0.25% acidifier A; 3) 0.3% acidifier B; 4) 0.5% acidifier C); 5) 50 g/ton carbadox; and 6) 400 g/ton chlortetracycline (CTC). Upon weaning, a common diet with no antibiotics or additives was fed for 21 d (Phases 1 and 2; days −21 to 0), followed by a 21-d experimental period (Phase 3; days 0 to 21) where treatment diets were fed. Pigs and feeders were individually weighed on a weekly basis to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F). Data were analyzed using the PROC GLIMMIX procedure of SAS (v 9.4, SAS Inst., Cary, NC) with pen as the experimental unit, treatment as a fixed effect, and room as a random effect. Dietary treatment had a significant impact (P < 0.05) on ADG, ADFI, and G:F each week and for the overall experimental period (days 0 to 21). Specifically, from days 0 to 7, pigs fed CTC had increased (P = 0.001) ADG compared with those fed acidifier B, acidifier C, and carbadox, whereas pigs fed the negative control and acidifier A diets were intermediate. Additionally, pigs fed the CTC diet had improved (P = 0.0002) ADFI when compared with all other treatments. From days 7 to 14 and days 14 to 21, pigs fed the carbadox diet had decreased (P < 0.0001) ADG compared with all other treatments. During the overall period (days 0 to 21), pigs fed diets containing carbadox had reduced ADG and ADFI (P < 0.0001), whereas pigs fed CTC had improved (P < 0.0001) ADG compared with all other treatments. Additionally, blood parameters, fecal consistency, and fecal microbial populations were analyzed on a subset of pigs (n = 5 pigs/treatment). Dietary treatment significantly affected (P < 0.05) concentrations of protein, globulin, phosphorus, alkaline phosphatase, and sorbitol dehydrogenase in the blood. Treatment also significantly impacted (P = 0.0005) fecal score but did not affect (P = 0.59) fecal microbial growth from days 0 to 21. In summary, CTC continues to be a valuable additive to improve performance in the nursery. Further investigation surrounding the efficacy of dietary acidifiers as antibiotic alternatives is warranted given inconclusive evidence in this study.

150 Effects of specialty lipids as alternatives to conventional antimicrobial feed additives on nursery pig growth performance

There is consumer and regulatory pressure to reduce the use of conventional antimicrobial feed additives in pork production. A total of 360 pigs (DNA 241×600, initially 5.4±0.07 kg BW) were used in a 35-d study evaluating the ability for specialty lipids to replace ZnO or carbadox in nursery diets. Pigs were allotted in a completely randomized design (6 pigs/pen and 10 pens/treatment) to one of six diets: 1) control; 2) control + 3,000 ppm ZnO in phase 1 and 2,000 ppm ZnO in phase 2; 3) control + 50 g/ton carbadox; 4) control + 1% C6:C8:C10 medium chain fatty acid (MCFA) blend; 5) control + 1% proprietary oil blend (Feed Energy Corp., Des Moines, IA); and 6) control + 1% monolaurate blend (FORMI GML, ADDCON GmbH, Bitterfeld-Wolfen, Germany). Treatment diets were fed in two phases (d 0 to 19) followed by a common diet (d 19 to 35). During the treatment period, pigs fed ZnO or carbadox had greater (P&lt; 0.05) ADG than pigs fed the control or proprietary oil blend, with pigs fed the MCFA or monolaurate blends being intermediate. Pigs fed diets containing ZnO had greater (P&lt; 0.05) ADFI than those fed the control, MCFA, or propriety oil blends. Pigs fed ZnO or carbadox had higher (P&lt; 0.05) blood glucose on d 19 and firmer (P&lt; 0.05) fecal scores on d 3 than pigs fed all other diets. No differences (P &gt;0.05) were observed during the common period (d 19 to 35), however sufficient early growth differences subsequently impacted overall ADG and ADFI. In summary, ZnO and carbadox are valuable additives to maximize early nursery growth, but specialty lipid products may result in similar performance while others may restrict it. Additional research is warranted to identify optimal lipid blends to effectively replace ZnO or carbadox in nursery pig diets.

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305 Awardee Talk: Transferring a culture of biosecurity to the feedmill

A culture of on-farm biosecurity has been established and practiced by modern swine production systems for many years. The value of this has been repeatedly demonstrated through improved animal health and performance based on the prevention of disease introduction to the herd. With the introduction of Porcine Epidemic Diarrhea Virus (PEDV) to the US swine industry in 2013, we have learned that feed and feed ingredients can be vectors of disease transmission. Therefore, there is a heightened need to transfer our on-farm biosecurity culture to our feedmills and entire feed supply chain as a way to help prevent disease introduction into swine farms. Feedmills are designed to efficiently and effectively blend feed components into a homogenous batch, and the potential to distribute contaminated feed to multiple farms is significant. While feed and ingredients can be vectors of disease and pathogen transmission, our data continues to show that people are a major risk for pathogen transmission throughout the feed supply chain. Key biosecurity principles such as exclusion, prevention, isolation, mitigation, disinfection, and containment should be adopted and enforced for a strong feedmill biosecurity program. A written feedmill biosecurity plan should be developed and a training program that covers all employees as well as visitors and delivery drivers should be implemented. Continuous risk assessment and environmental monitoring should be utilized to identify new areas of risk and to assess the current status. Unfortunately, feedmills are nearly impossible to completely disinfect and therefore every effort should be made to prevent the introduction of pathogens into the mill. Research that we have conducted with PEDV and African Swine Fever Virus has demonstrated that adopting a culture of biosecurity at the feedmill will reduce risk of disease and pathogen exposure on farms.

PSI-6 Effects of rest period prior to processing on vaccine response and blood metabolites in feedlot heifers

It is common for feedyards to rest cattle after transport and prior to administration of their receiving vaccinations in an attempt to minimize transport stress and optimize vaccine efficacy and subsequent growth and performance. This study aimed to test how time of rest after feedlot heifer arrival impacts vaccine titer and blood metabolites indicating cattle health. Eighty mixed-breed heifers (250 ± 4.2 kg BW) were purchased at live auction in Oklahoma City, OK and transported to the Kansas State University in Manhattan. Heifers were allotted in a completely randomized design to one of four treatments processed at 0, 6, 24, or 48 hours after arrival. At the time of processing (d 0) and again on d 35, serum samples were collected and analyzed for infectious bovine rhinotrachitis (IBR) titer, large animal chemistry panel, and hepatic profile by the Kansas State Veterinary Diagnostic Laboratory. There were time × treatment interactions (P &lt; 0.02) for serum IBR titer, glucose, urea nitrogen, and bicarbonate. Specifically, heifers had greater (P &lt; 0.05) IBR titer on d 35 than d 0, as expected because they were vaccinated upon arrival. Upon arrival, cattle held for 48 hours prior to processing had significantly greater (P &lt; 0.05) glucose than those held for 24 hours (108 vs. 68 mg/dL, respectively), with no differences in processing treatment by d 35. Urea nitrogen levels in cattle held for 6, 24, or 48 hr prior to processing were greater (P &lt; 0.05) than those held for 0 hours on d 0 or for any length of time by d 35. Finally, cattle held for 0 or 48 hr prior to processing had lower (P &lt; 0.05) bicarbonate levels on d 0 than those held for 6 or 24 hours by d 35. These data show that while initial rest may be helpful to normalize blood metabolites, cattle should be placed within 24 hours of arrival. However, most blood metabolite levels normalize within 35 days.