Abstract The rise in antibiotic resistance is an emerging global problem that affects not only humans but also livestock. This increase in antimicrobial resistance may partly be due to the overuse or misuse of antibiotics in livestock. Growing evidence indicates that antibiotic use in livestock influences the emergence of antibiotic-resistant pathogens. To test the impact of antibiotic use on the gut microbial ecology in pigs, we evaluated the impact of two currently used antibiotics (carbadox/copper sulfate (AB1) and chlortetracycline/tiamulin hydrogen formate (AB2)) in nursery pigs. To this end, a 56-day feeding trial was conducted using 192 pigs with an average body weight (BW) of (3.1 ± 0.73 kg) in two replicates (96 pigs per rep). The pigs were assigned to one of three dietary treatments (CON: No antibiotics, AB1: Carbadox/copper sulfate, AB2: Chlortetracycline/tiamulin) with 4 pens per treatment and 8 pigs per pen in a randomized complete block design in each replicate. Fecal samples were collected on day 28 of birth before administration of treatments and on the last day of nursery stage (day 56) after antibiotics for microbiome analysis. The bacterial community composition of the fecal samples was assessed by sequencing the V4 region of the 16S rRNA gene. The AB1 and AB2 groups demonstrated a significantly greater number of bacterial taxa (amplicon sequence variants (ASVs)) compared to the no antibiotic treatment for both reps. Beta -diversity identified distinctive clustering between baseline and treated groups (AB1 and AB2) and revealed significant differences in bacterial community composition when CON vs AB1 or AB2 were compared (p < 0.05). Differential abundance analysis identified several significant ASVs in the treated groups (AB1 and AB2), including members of the genera Lactobacillus, Faecalibacterium, Segatella, and Akkermansia. Additionally, microbial community profiling indicated that the genus Lactobacillus and phylum Bacillota varied between treated and untreated pigs. Overall, these findings provide important insights into the immediate impacts of antibiotic exposure on the porcine gut bacteriome, and future work will focus on assessing long-term effects through a longitudinal study investigating AMR gene abundance and AMR gene -taxa relationships in the gut microbiome to develop microbiome-based intervention strategies to mitigate antibiotic use.

Abstract Recent studies have shown that prebiotics have been able to positively affect growth of beneficial bacteria, indices of gut health, and growth performance in pigs. This type of research is important to identify alternative methods for maintaining herd health other than antimicrobial usage. Jerusalem Artichoke tubers were chosen due to their relatively greater amount of inulin (~60%) compared with other prebiotic crops (i.e., chicory pulp - ~20% inulin). The objective of this work was to evaluate growth performance of weaned pigs fed Jerusalem Artichoke tubers. Sixty-four pigs approximately 21 d of age, weighing 6 kg each were used to test four dietary treatments with four pens per treatment (two barrows and two gilts per pen). Dietary treatments were randomly allocated to pens following a completely randomized design in a three-phase feeding trial. Diet treatments consisted of a corn-soybean meal basal diet (control) meeting the nutrient requirements for weanling pigs and three treatment diets with ground Jerusalem Artichoke tubers replacing corn at the rate of 0.05%, 0.5%, and 5.0% (JA-low, JA-mid, and JA-high, respectively) through all three phases. The pigs were allowed 3 d to acclimate to the facility following arrival (d -3 to -1). The trial ran from d 0 to d 35. Growth performance data were collected on d 0, 7, 14, 21, 28, and 35. Blood samples were obtained on d 0, 7, 14, and 28. Fecal samples were collected on d 0, 14, and 28. PROC GLIMMIX in SAS was utilized to analyze the growth performance data. Results indicate greater (P < 0.001) gain to feed ratio (G:F) at wk 2 for JA-high and JA-mid pigs compared with all other treatments. No differences were observed for overall body weight (BW; 25.14, 25.48, 21.8, 22.83 kg), average daily gain (ADG; 0.52, 0.52, 0.51, 0.47 kg/d), or average daily feed intake (ADFI; 0.73, 0.74, 0.71, 0.72 kg/d), respectively, for control, JA-low, JA-mid, and JA-high fed pigs. The growth data suggests that Jerusalem Artichoke tubers may be included in weaned pig diets without negative effects on growth performance; however, these results need to be interpreted in conjunction with the pending analyses to provide a comprehensive look at the role of prebiotic fiber in the gastrointestinal tract of the pig. Future analyses will include evaluation of serum biomarkers (e.g., intestinal fatty acid binding protein as a measure of intestinal epithelial cell damage) and microbiome profiling via 16S microbial sequencing to assess gut health. It is important to note that our study population experienced morbidity and mortality (Trueperella pyogenes was cultured from one pig submitted for necropsy) and the decision was made to prophylactically treat the herd with ceftiofur on d 7 following sample collection to prevent additional loss.

Early-life microbiome establishment and colonization is essential for gut development, nutrient digestion and metabolism, and modulation of the immune system. Microbial colonization of the infant digestive tract begins at birth, and as such, maternal microbiota has an important influence on the early-life establishment and colonization of the infant gut microbiota. Therefore, perturbations during early life establishment of the infant gut microbiome may have long-term impact on the microbiota composition and function, and may serve as a major determinant on host health and development. To evaluate the effects of early life microbiomes on long-term colonization of the microbiome, and effect host function, we set out to quantify the percentage of the sow microbiome that contributes to early-life colonization in the piglet and how such microbiomes would persist within the piglet gut. To this end, we investigated the colonization history and the role of the sow microbiome in establishment of the piglet microbiome over time using 16S rRNA sequencing. We observed 125 amplicon sequence variants to be persistent across different sampling time points, day 0, day 14, and day 21, representing 89.73%, 68.99%, and 67.30% of the total reads on day 0, day 14 and day 21, recovered from the piglets respectively. Comparing the piglet microbiota to that of the sow, we observed 114 of the 125 persistent ASVs in the piglet microbiota to arise from the sow that account for 75% of the total reads in the sow microbiota. This core microbiome includes Bacteroides, Methanobrevibacter, Lachnoclostridium, Lactobacillus, Escherichia-Shigella, Clostridium sensu stricto 1, Christensenellaceae R-7 group, Ruminococcaceae Genus, Romboutsia, Phascolarctobacterium, Erysipelotrichaceae Genus, Muribaculaceae Genus, Streptococcus, [Eubacterium] coprostanoligenes group Genus and others. The species abundance increased for Bacteroides, Methanobrevibacter, Lachnoclostridium, Clostridium sensu stricto 1, Lactobacillus, Christensenellaceae R-7 group, Ruminococcaceae Genus, Romboutsia, Phascolarctobacterium, Erysipelotrichaceae Genus, Muribaculaceae Genus, Streptococcus, [Eubacterium] coprostanoligenes group Genus and other species over time while species abundance of pathogens or opportunistic pathogens such as Escherichia-Shigella and Salmonella species decreased over time. In conclusion, the maternal microbiota has an important role in early-life microbiome establishment and can be utilized to develop a more beneficial microbiome to increase pig health and productivity.

Microbiome research has gained significant momentum in the last decade. Although many studies have investigated livestock microbiome to improve animal health and productivity, only a few microbiome manipulation approaches are currently used in the industry. This is partly due to the limited understanding of livestock microbiome and how such knowledge can be applied to improve animal health and performance. Additionally, the potential role of the microbiome is poorly characterized, limiting the opportunities available to improve animal health and productivity through microbiome manipulation. Here we describe and demonstrate how current microbiome theory such as “colonization history” can be utilized to establish beneficial microbiomes in livestock species. Our data suggest that the sow microbiome greatly impacts the early microbiome establishment in piglets and represents as much as 67% of the community even after 21 days following birth. This suggests early colonization provides unique opportunities to establish “beneficial” microbiomes. Additionally, we describe how microbiome-wide association studies (MWAS) can be used to quantify the microbial role in animal performance using a cattle population consisting of more than 750 animals. Finally, we describe how livestock animal models can be used to understand key concepts of microbial establishment and how such models can be used to investigate the human microbiome using germ free pig models. USDA is an equal opportunity provider and employer.

The cecum is a major site of fermentation of dietary nutrients. In the pig, there is a knowledge gap pertaining to the role of the cecum in nutrient metabolism and health. The objective of this preliminary work was to develop a caecectomized pig model and to evaluate cecum microbial community structure in cecectomized finisher pigs fed a high fibre diet. Caecectomies were performed at the nursery to grower phase transition (∼ 63 d of age) prior to the experiment. A total of 10 barrows (initial BW = 83 kg; ∼112 d of age) were allotted to 1 of 2 treatments (5 replicates/treatment) in a 4 wk experiment. Treatments consisted of caecectomized (CEC-) or cecum intact (CTRL) pigs. All pigs were fed a moderately complex, high fibre (soy hulls included at 25%) finisher diet (3,006 ME kcal/kg) during the entirety of the trial. Data was analysed using PROC MIXED procedures of SAS with treatment as fixed effect and initial BW block as random effect. No differences were observed in BW on d 0 (82.92 vs 83.92 kg) or d 28 (110.78 vs 114.36 kg) between treatments (CEC- vs CTRL, respectively). During wk 4 CTRL pigs tended to have greater (P<0.09) ADFI compared to CEC- pigs (4.39 vs. 3.45 kg/d). Faecal samples (obtained on d 0, 14, and 28) were used to evaluate phylum-level bacterial community structure by sequencing the V4 region of the 16S rRNA gene. No significant differences were observed in microbial community structure between treatments over the time course of the experiment. Preliminary data suggests there may be utility in development of a caecectomized pig model to evaluate the role of the caecum in pig nutrient metabolism and health. Additional analyses are in process to investigate fibre digestion kinetics and bacterial community structure at the genus/species levels.

Atypical porcine pestivirus (APPV), an RNA virus member of the Flaviviridae family, has been associated with congenital tremor in newborn piglets. Previous qPCR-based assays, targeting the polyprotein coding sequences of APPV, were unable to detect the virus in novel cases of congenital tremor originated from multiple swine farms from the U.S. Midwest (MW). The polyprotein coding genes of APPV were characterized by a low level of sequence conservation ranging from 58.2 to 70.7% among 15 global APPV strains. In contrast, the 5’ untranslated region (UTR) was found to have a much greater degree of sequence conservation of 81.0% seen among the 15 global and new 4 MW strains, and as high as 91.5% when comparing only 5 MW strains. The complete 5’ UTR sequence of the APPV strains originated from MW was obtained by utilizing the template switching approach followed by amplification and dideoxy sequencing. Notably, previously identified potentially crucial regions for the correct function of the APPV internal ribosome entry site (IRES) were found to overlap with the most highly conserved 5’UTR segments, suggesting their functional role in viral protein translation. By targeting 100% conserved 5’UTR regions across 19 global and MW strains, a new qPCR assay was designed which was able to detect APPV in well documented cases of congenital tremor which originated from 5 MW farm sites (1-18 samples/site). The assay was found to have a detection sensitivity of 6.5 APPV copies (Cq ~38.4). Due to the potential functional importance of the highly conserved 5’UTR sequences targeted by our newly developed qPCR assay, we expect that assays targeting this region would broadly detect APPV strains that are diverse in space and time.

Weaning stress and the negative health effects that occur with it cause serious concerns for pork producers. The abrupt environmental and dietary transitions that occur at weaning often take place before the gut microbiome is stabilized in the piglet. This leaves weanling piglets vulnerable to gut dysbiosis and increases susceptibility to enteric pathogens. The infections by opportunistic pathogens can be prevented with antibiotics, but due to growing concerns surrounding antimicrobial resistance in bacterial populations, direct-fed microbial (DFM) formulations have emerged as an alternative prevention method. In the current study, we isolated Lactobacillus spp. and Bifidobacterium spp. from fecal samples collected from neonatal pigs and sows that are capable of inhibiting colonization of Salmonella spp. and Escherichia coli isolated from sick pigs. Diluted fecal samples were plated on Bifidus selective medium (BSM) and deMan, Rogosa Sharpe (MRS) medium to isolate Bifidobacterium and Lactobacillus, respectively. Bacterial isolates were screened against Salmonella and E. coli isolates of porcine origin using a medium consisting of 50% MRS and 50% brain, heart, lung infusion (BHI) using disk diffusion assays. The resulting isolates that demonstrated the greaest degree of pathogen inhibition were characterized using 16s rRNA sequencing. Sequence analysis identified the top isolates as L. mucosae, L. reuteri, and B. thermacidophilum subsp. porcinum. Currently, genome sequencing of the selected isolates is underway to identify the mechanisms of inhibition.

Abstract Digestive Physiology of Pigs (DPP) was organized in 1979 to promote exchange of information among scientists working in swine digestive physiology and nutrition. The objective of this presentation is to provide an overview of the past, present, and future of the most important global scientific event in the fields of pig gut physiology and nutrition. To date, fourteen symposia have been conducted including the 12th International Symposium, which was held in Keystone, Colorado (DPP-2012). In order to facilitate the activities of DPP-2012, DPP-North America was established as a non-profit entity with a mission to collaborate internationally to “establish triennial venues that present the most current research and discovery information relative to digestive physiology of pigs.” Regarding DPP-2012, 403 attendees from 28 countries were in attendance, and 250 abstracts were accepted for presentation. The attendees represented academia, industry, and major swine production entities. Today, in addition to digestive physiology and nutrition, the global DPP community has evolved to include topics such as immunology, microbiology, and the use of pigs as a model for human health. As part of the global DPP community, DPP-North America continues to work with the global DPP community to establish global networks, to learn about the latest scientific discoveries, to promote academia-industry partnerships, to involve and train the next generation of scientists, and to contribute to sustainable pork systems. Since its establishment, DPP-North America has sponsored digestive physiology lectures at the annual ASAS Midwest meetings and has provided travel scholarships for North American graduate students to attend and present research at international DPP meetings.

An experiment was conducted to evaluate the effects of increasing the inclusion of proso millet on the growth performance of growing and finishing pigs. Using a randomized complete block design, 36 crossbred barrows, with an average initial weight of 22.2 kg, were randomly assigned to 1 of 4 dietary treatments (9 pens/treatment; 1 pig/pen). Diet 1 was corn-soybean meal-based (control) and Diets 2, 3, and 4 had proso millet replacing 33%, 67%, and 100%, respectively, of corn in the control diet. The diets were formulated according to 4 growth phases (P1, 25 to 50 kg BW; P2, 50 to 75 kg BW; P3, 75 to 100 kg BW; and P4, 100 to 135 kg BW) with nutrient contents formulated according to NRC (2012) recommendations. Data were analyzed using the GLIMMIX procedure of SAS, using pig as the experimental unit. In P1 and P2, no differences in average daily gain (ADG) or average daily feed intake (ADFI) were observed among treatments (P > 0.3). In P3, pigs consuming the proso millet diets had greater ADFI than pigs consuming the basal diet, especially pigs fed Diet 4 compared to pigs fed Diet 1 (3.66 vs. 3.29 kg; P < 0.01). The ADG:ADFI ratio was not affected (P > 0.1) by treatments during this period. In P4, although there was a difference in ADFI between pigs fed Diet 3 and Diet 1 (3.8 vs. 3.47 kg; P = 0.04), no decreases in ADG:ADFI ratio were observed among the four dietary treatments (P > 0.5). Average daily gain was not affected (P > 0.3) by treatments during the growing-finishing period, suggesting that the level of corn replacement up to 100% by proso millet did not affect pig growth. In conclusion, proso millet was shown to effectively replace corn in corn-soybean meal-based diet for growing-finishing pigs without compromising growth performance.

This disclosure describes novel probiotics, and also describes novel methods by which such probiotics can be obtained.

The objective of the study was to determine hair cortisol concentrations in sows in two different housing systems. Sows (n = 66, parity 0–6) were housed at the SDSU sow facility and assigned to one of two housing systems, stalls (STL) or group pens (PEN). The STL sows (n = 34) were housed in gestation stalls from breeding until d111 ± 1.1 of gestation; PEN sows (n = 32) were moved to 3 pens approximately 24 h after breeding in a dynamic group sow housing system. All females were housed in stalls at least 5d prior to breeding. All sows were moved to farrowing crates at approximately d111 of gestation. Hair was shaved from the right hip within 5d of breeding (defined as d0). At d37, d74, and d111 of gestation the same area was shaved and hair collected; samples from d37 and d111 were analyzed for cortisol. In the statistical model, main effects of housing system, time, and their interactions were tested with parity as random effect. Sows were later assigned a parity group [0–1 (n = 23), 2–3 (n = 17), and 4–6 (n = 26)] to assess the interactions between parity and treatment. There was a treatment by parity interaction (P < 0.05) where parity 0–1 STL group had higher cortisol (75.6 pg/mg) than parity 0–1 PEN group (24.2 pg/mg) and no effect of housing on parity 2–3 and 4–6 groups. Across parity, STL sows had greater (P < 0.05) overall hair cortisol than PEN sows (49.4 vs 19.8 ± 8.0 pg/mg hair). Hair cortisol concentration tended to be lower (P = 0.06) at d37 than d111 (29.4 vs 39.8 ± 8.0 pg/mg) and no time by treatment interaction was observed. These results suggest that young sows experience greater stress in individual stall housing than in group housing and that cortisol increases with progressing gestation regardless of housing system.

The use of probiotics may be an effective strategy in sustainable pig production. The objective of this experiment was to examine the effects of Lactobacillus fermentum LfQi6 (LF) on sow and litter performance. First parity, gestating sows (UNL Resource Population Rep x DNA Genetics Duroc; n = 28) were allotted one of two treatment groups. Treatment groups consisted of a control group (CTL) fed a standard gestation and lactation diet for the duration of the study, while the experimental group was fed CTL supplemented with 10^10 CFU LF per day from d 80 of gestation through lactation. Individual piglet body weights (BW) were recorded weekly. LF sows tended to enter the farrowing crates lighter than the control sows (209.93 vs 200.91kg; P = 0.0794). LF sows had a smaller loin eye area when compared to CTL sows (6.24 vs 5.86 cm2; P = 0.0374) when entering the farrowing crates. However, LF sows tended to lose less loin area per day when in the crate (0.025 vs 0.012 cm2/d; P = 0.078); resulting with there being no difference in loin area when the sows left the farrowing crates. Piglet BW tended to be greater at weaning for the sows fed the LF (5.37 vs 5.66 kg, P = 0.0528). The mean piglet BW were 1.25,1.33; 2.37,2.44; 4.08,4.22; and 5.37,5.66 at d 0, 7, 14, 21; respectively for CTL and LF. Sows fed the LF had fewer pigs born alive per litter (16.09 vs 14.12; P < 0.05) when compared to the sows fed the control diet. However, piglet mortality tended to be decreased for LF compared to CTL (3 vs 1.76; P = 0.0645). Results suggest that supplementation with Lactobacillus fermentum LfQi6 may provide some benefits with respect to sow and litter performance.

Reduction in dietary crude protein and addition of fiber could mitigate the incidence and severity of post-weaning diarrhea, a common gastrointestinal condition in newly weaned pigs. Therefore, 360 weanling pigs, initially 5.0 ± 0.10 kg, were used to evaluate the effects of crude protein (CP) level and fiber source on growth performance and fecal microbial communities. At weaning, pigs were randomly assigned to pens and allotted to 1 of 8 dietary treatments in a 2 × 4 factorial with main effects of CP (21 or 18%) and fiber source (none, coarse wheat bran, oat hulls, or cellulose). There were 5 pigs per pen and 9 pens per treatment. Experimental diets were formulated in two dietary phases from d 0 to 10 and 10 to 24, with a common post-treatment diet fed from 24 to 45. The 21% CP diets contained 1.40% standardized ileal digestible (SID) Lys in phase 1 and 1.35% SID Lys in phase 2. By using a maximum SID Lys:digestible CP ratio of 6.35%, the 18% CP diets contained 1.25% SID Lys in both phases. Diets containing a fiber source were formulated to the level of insoluble fiber provided by 4% coarse wheat bran, resulting in the addition of 1.85% oat hulls and 1.55% cellulose. No fiber source × CP level interactions (P > 0.05) were observed. Decreasing CP (and subsequently SID lysine) decreased (P = 0.05) ADG and G:F during the experimental period. From d 0 to 45, ADG decreased (P = 0.05) for pigs fed 18% CP diets compared to pigs fed 21% CP. No effect of fiber source was observed for growth performance. Fecal DM on d 17 increased (P < 0.001) for pigs fed 18% CP diets compared to pigs fed 21% CP diets. Pigs fed diets with added cellulose had increased (P < 0.05) fecal dry matter during the experimental period compared to pigs fed no fiber source or wheat bran. Bacterial community structure was investigated by sequencing the V4 region of the 16S rRNA gene. Analysis indicated a significant difference between CP content at d 24 (P = 0.023) using a Weighted UniFrac distance matrix. Further investigation identified five differential Amplicon Sequence Variants associated with CP content at d 24. In conclusion, reducing crude protein (and subsequently SID Lys) decreased growth performance but increased fecal dry matter content. The source of dietary fiber in nursery diets had no impact on growth performance; but pigs fed added cellulose had increased fecal DM compared with other treatments. Microbial analysis identified differential taxa associated with CP content.

Atypical porcine pestivirus (APPV), an RNA virus member of the Flaviviridae family, has been associated with congenital tremor in newborn piglets. Previously reported quantitative polymerase chain reaction (qPCR)-based assays were unable to detect APPV in novel cases of congenital tremor originated from multiple farms from U.S. Midwest (MW). These assays targeted the viral polyprotein coding genes, which were shown to display substantial variation, with sequence identity ranging from 58.2% to 70.7% among 15 global APPV strains. In contrast, the 5'-untranslated region (5' UTR) was found to have a much higher degree of sequence conservation. In order to obtain the complete 5' UTR of the APPV strains originated from MW, the 5' end of the viral cDNA was obtained by using template switching approach followed by amplification and dideoxy sequencing. Eighty one percent of the 5' UTR was identical across 14 global and 5 MW strains with complete or relatively complete 5' UTR. Notably, some of the most highly conserved 5' UTR segments overlapped with potentially important regions of an internal ribosome entry site (IRES), suggesting their functional role in viral protein translation. A newly designed single qPCR assay, targeting 100% conserved 5' UTR regions across 19 strains, was able to detect APPV in samples of well documented cases of congenital tremor which originated from five MW farm sites (1-18 samples/site). As these fully conserved 5' UTR sequences may have functional importance, we expect that assays targeting this region would broadly detect APPV strains that are diverse in space and time.

The use of probiotics may be an effective strategy in sustainable pig production. The objective of this experiment was to examine the effects of Lactobacillus fermentum (LF) on nursery pig performance. Weaned pigs (n = 70; average initial BW 6.464 kg) were randomly allotted to 1 of 3 treatments, forming 6 replicates per treatment. Treatments included: 1) pigs fed a standard nursery diet (NRC 2012); CTL; 2) pigs fed CTL with the addition of 10^10 CFU LF per day for phase 1 (wk 2 and 3; LF1); and 3) pigs fed CTL with the addition of 10^10 CFU LF per day for phase 1 and phase 2 (wk 2 thru 5). A common diet was fed during adaptation (wk 1) and during a wash out phase (wk 6). Individual piglet BW were recorded weekly along with pen feed disappearance. No differences were observed in BW by the end of phase 1; at the end of phase 2 the pigs fed LF had a lower BW than the others (19.38, 19.22, 17.3 kg; P = 0.031). This was associated with a reduced feed efficiency seen in week 5 (0.679, 0.656, 0.445; P = 0.0404). However, no differences (P > 0.10) were observed in BW of the pigs throughout the trial and final BW were 24.15, 24.45, 24.3 kg. No differences were observed in ADFI between treatments (ADFI Phase 1: 0.359, 0.366, 0.353 kg/d;P = 0.965; Phase 2: 0.906, 0.896, 0.843 kg/d; P = 0.578; Phase 3: 1.183, 1.227, 1.196 kg; P = 0.920). Results suggest that pigs fed diets supplemented with Lactobacillus fermentum performed similar to pigs fed a conventional diet.

Addition of pre- and probiotics may confer growth and health benefits when added to the diet of pigs. To determine the effects of feeding mannan oligosaccharide (MOS) and Lactobacillus mucosae (LM) as prebiotic and probiotic sources in weanling pigs under immune challenge, 96 weaned pigs were randomly allotted to 16 experimental pens within a 2 × 2 factorial arrangement of treatments. Control diets with or without 0.1% yeast-derived MOS were randomly assigned to pens and 109 cfu/pig LM broth or a control broth were top-dressed daily. Pigs were fed one of four dietary treatments (control, MOS, LM, and MOS+LM) in Phases I and II (days 0 to 7 and days 7 to 21 postweaning, respectively) and a common diet during Phase III (days 21 to 35 postweaning). On day 14, all pigs were challenged with 100 µg/kg body weight (BW) Escherichia coli lipopolysaccharide (LPS) via intraperitonial injection. Feed disappearance and pig BW were measured weekly. Blood and fecal samples were collected weekly, and additional blood samples were collected on days 1 and 3 post-LPS challenge. On days 15 and 21, one pig per pen was euthanized for collection of ileal mucosa and duodenal and ileal tissue samples. From days 0 to 14, feeding LM decreased gain-to-feed ratio (G:F; P < 0.05). An interaction between LM and MOS was observed for G:F on days 14 to 21 (P < 0.05); G:F in LM (715 g/kg) was greater compared with MOS+LM (P < 0.05; 600 g/kg) and control (P < 0.10; 615 g/kg), but was not different (P > 0.10) from MOS (674 g/kg). After pigs were fed a common diet (days 21 to 35), G:F was decreased (P < 0.05) in the LM treatment groups. Pigs fed diets that included MOS had increased serum immunoglobulin (Ig) G on days 1 and 3 post-LPS challenge and 2 wk after removal of treatments (P < 0.05) and on days 14 and 21 postweaning (P < 0.10) compared with pigs fed diets without MOS. On day 15, mucosal immunoglobulin G was increased (P < 0.05) in control vs. MOS and LM groups. Circulating IL-1β in control and MOS+LM pigs increased (P < 0.05) on day 1 post-LPS challenge but did not change (P > 0.10) in MOS and LM groups. On day 15, pigs fed LM had decreased (P < 0.05) ileal crypt depth compared with pigs fed the control diet. On day 21, fecal propionate and butyrate tended to be lower (P < 0.10) in pigs fed MOS vs. control and MOS+LM diet. These preliminary findings suggest that feeding LM alone improved feed efficiency and ileal morphological structure during the first week of LPS challenge; additionally, feeding LM and MOS may have beneficial effects relative to immune biomarkers.

An assessment of undergraduate involvement in research at the University of Nebraska-Lincoln using participant surveys has shown the benefits of knowledge gained and given insight for design and success of undergraduate participation in research in the animal science department. Current undergraduate students who had participated in some form of animal science research were surveyed with both demographic questions and ones based on intrinsic and extrinsic factors affecting research were evaluated. On the survey, students were asked rank statements on a 1 (strongly disagree) to 5 (strongly agree) Likert-type scale to analyze the impacts of completing undergraduate research and the effects it has on one’s knowledge and ability to use and apply what was taught. A total of 30 students completed the survey. Ten percent of students that participated in the survey were male and the other 90% were female. Students ages ranged from 18-23 with the majority being 20-21 (46%) and seniors (33.3%) as well as a Nebraska resident (78%). Students expressed that they mostly heard about the undergraduate research opportunity from their professor (48%) or an outside source such as pre-vet or class presentations (36%). Sixty percent of individuals indicated that pre-veterinary medicine was their current career choice with only 4% indicating they did not plan to continue a higher degree post undergraduate. Interestingly, undergraduate students felt graduate students had a greater impact on their research compared to the professor (43% vs 36%) while 21% of participants said neither had an impact on their research as an undergraduate. Students felt many benefits from participating in undergraduate research from educational opportunities, such as feeling more prepared/competitive for graduate school to life skills, including greater knowledge, reasoning and problem-solving. In conclusion, from participating in undergraduate research, participants are able enhance their scientific learning skills that will help them in their future.