Feed additive blends fed to nursery pigs challenged with Salmonella

Examination of Salmonella Prevalence in Pigs Through Rye-Based Feeding and Coarser Feed Structure Under Field Conditions

INTRODUCTION

Salmonellosis is the second most commonly occurring bacterial zoonosis in Germany. Rye in pig feeding offers new possibilities for addressing that issue due to its high content of non-starch polysaccharides (NSPs). These are fermented in the intestinal tract to specific fermentation products, which seem to have bacteriolytic effects against Salmonella. A coarse feed structure can display synergistic effects.

METHODS

Seven conventional pig fattening farms increased the rye content (40%-70%) while limiting the amount of fine particles (maximum of 20% ≤0.25 mm). Samples from pigs were tested for Salmonella antibodies and compared with samples from 167 farms without any changes to the feed.

RESULTS

Rye-based diets had a significant (p < 0.05) impact on Salmonella antibody (percentage optical density [OD%]) detection. In this study, it became apparent that significantly fewer positive OD% values could be detected due to the increase in rye compared to farms that did not change the feed (Farm 6 P0: 35.45 ± 36.18; P1: 15.48 ± 16.98; P2: 9.36 ± 8.17). An elimination of Salmonella could not be achieved, but especially farms with high antibody counts were able to strongly reduce those in both phases consecutively (Farm 5 P0: 35.17 ± 35.53; P1: 18.56a ± 20.96; P2: 13.38a ± 18.99). That was different on farms without adapted feeding, where an increase in Salmonella antibodies was observed (P0: 17.38 ± 22.21; P1: 20.12 ± 25.39; P2: 18.12 ± 25.44).

CONCLUSION

By increasing the proportion of rye and limiting the proportion of fine particles in the feed, Salmonella antibodies (OD% values) in meat juice and blood can be significantly reduced, especially on farms with an initially high incidence of Salmonella. If that is implemented in feeding across the board on farms, an improvement in food safety and a decreased risk of zoonosis can be expected.

The Metabolic Pathway of Bile Secretion Is Vulnerable to Salmonella enterica Exposure in Porcine Intestinal Epithelial Cells

Pigs can be colonized with Salmonella enterica and become established carriers. However, the mechanisms of the host's response to Salmonella enterica infection are largely unclear. This study was constructed with the Salmonella enterica infection model in vitro using porcine intestinal epithelial cells (IPEC-J2). Transcriptome profiling of IPEC-J2 cells was carried out to characterize the effect of Salmonella enterica infection and lipopolysaccharide (LPS) treatment, in which LPS-induced inflammation was a positive control. At first, Salmonella enterica infection increased the cell apoptosis rate and induced an inflammation response in IPEC-J2. Then, the up-regulated genes were enriched in metabolic pathways, such as those for bile secretion and mineral absorption, while down-regulated genes were enriched in immune-related pathways, such as the Toll-like receptor signaling and p53 signaling pathways. Moreover, we found 368 up-regulated genes and 101 down-regulated genes in common. Then, an integrative analysis of the transcriptomic profile under Salmonella enterica infection and LPS treatment was conducted, and eight up-regulated genes and one down-regulated gene were detected. Among them, AQP8 is one critical gene of the bile secretion pathway, and its mRNA and protein expression were increased significantly under Salmonella enterica infection and LPS treatment. Thus, the AQP8 gene and bile secretion pathway may be important in IPEC-J2 cells under Salmonella enterica infection or LPS treatment.

Agaricus subrufescens fermented rye affects the development of intestinal microbiota, local intestinal and innate immunity in suckling-to-nursery pigs

BACKGROUND

Agaricus subrufescens is considered as one of the most important culinary-medicinal mushrooms around the world. It has been widely suggested to be used for the development of functional food ingredients to promote human health ascribed to the various properties (e.g., anti-inflammatory, antioxidant, and immunomodulatory activities). In this context, the interest in A. subrufescens based feed ingredients as alternatives for antibiotics has also been fuelled during an era of reduced/banned antibiotics use. This study aimed to investigate the effects of a fermented feed additive -rye overgrown with mycelium (ROM) of A. subrufescens-on pig intestinal microbiota, mucosal gene expression and local and systemic immunity during early life. Piglets received ROM or a tap water placebo (Ctrl) perorally every other day from day 2 after birth until 2 weeks post-weaning. Eight animals per treatment were euthanized and dissected on days 27, 44 and 70.

RESULTS

The results showed ROM piglets had a lower inter-individual variation of faecal microbiota composition before weaning and a lower relative abundance of proteobacterial genera in jejunum (Undibacterium and Solobacterium) and caecum (Intestinibacter and Succinivibrionaceae_UCG_001) on day 70, as compared to Ctrl piglets. ROM supplementation also influenced gut mucosal gene expression in both ileum and caecum on day 44. In ileum, ROM pigs showed increased expression of TJP1/ZO1 but decreased expression of CLDN3, CLDN5 and MUC2 than Ctrl pigs. Genes involved in TLR signalling (e.g., TICAM2, IRAK4 and LY96) were more expressed but MYD88 and TOLLIP were less expressed in ROM pigs than Ctrl animals. NOS2 and HIF1A involved in redox signalling were either decreased or increased in ROM pigs, respectively. In caecum, differentially expressed genes between two groups were mainly shown as increased expression (e.g., MUC2, PDGFRB, TOLLIP, TNFAIP3 and MYD88) in ROM pigs. Moreover, ROM animals showed higher NK cell activation in blood and enhanced IL-10 production in ex vivo stimulated MLN cells before weaning.

CONCLUSIONS

Collectively, these results suggest that ROM supplementation in early life modulates gut microbiota and (local) immune system development. Consequently, ROM supplementation may contribute to improving health of pigs during the weaning transition period and reducing antibiotics use.

Chromatin Accessibility and Transcriptional Landscape during Inhibition of Salmonella enterica by Lactobacillus reuteri in IPEC-J2 Cells

Lactobacillus reuteri is a probiotic with bacteriostatic effects, which can effectively inhibit the activity of pathogens. However, the molecular mechanism underlying the inhibition of pathogens by L. reuteri in intestinal cells remains unclear. Using the porcine intestinal cell line IPEC-J2 as a model, we combined RNA-seq and ATAC-seq methods to delineate the porcine genome-wide changes in biological processes and chromatin accessibility in IPEC-J2 cells stimulated by Salmonella enterica BNCC186354, as well as L. reuteri ATCC 53608. Overall, we found that many porcine transcripts were altered after S. enterica BNCC186354 treatment, while L. reuteri ATCC 53608 treatment partially restored this alteration, such as salmonella infection and PI3K/AKT and MAPK pathways. Combined analysis of these two datasets revealed that 26 genes with similar trends overlapped between gene expression and chromatin accessibility. In addition, we identified potential host functional transcription factors (TFs), such as GATA1, TAL1, TBP, RUNX1, Gmeb1, Gfi1b, RARA, and RXRG, in IPEC-J2 cells that might play a critical role and are targeted by L. reuteri ATCC 53608. Moreover, we verified that PI3K/AKT, MAPK, and apoptosis pathways are potentially regulated by S. enterica BNCC186354 but restored by L. reuteri ATCC 53608. The PI3K/AKT pathway was activated by L. reuteri ATCC 53608, thereby potentially inhibiting S. enterica BNCC186354 infection. In conclusion, our data provide new insights into the expression pattern of functional genes and the epigenetic alterations in IPEC-J2 cells underlying the bacteriostatic action of L. reuteri ATCC 53608.

Evaluation of digestively resistant or soluble fibers, short- and medium-chain fatty acids, trace minerals, and antibiotics in nonchallenged nursery pigs on performance, digestibility, and intestinal integrity

Three experiments (EXP) were conducted to determine the effect of feed additives on performance, intestinal integrity, gastrointestinal volatile fatty acids (VFA), and energy and nutrient digestion in nonchallenged nursery pigs. In EXP 1, 480 pigs (6.36-kg body weight, BW) were placed into 96 pens with 5 pigs/pen, and allotted to 1 of 10 dietary treatments: 1) negative control containing no feed additive (NC), 2) NC + 44 mg chlortetracycline and 38.5 mg tiamulin/kg diet (CTsb), 3) NC + 5% resistant potato starch (RSpo), 4) NC + 5% soluble corn fiber (SCF), 5) NC + 5% sugar beet pulp (SBP), 6) NC + 0.30% fatty acid mix (FAM), 7) NC + 0.10% phytogenic blend of essential oils and flavoring compounds (PHY), 8) NC + 50 mg Cu and 1,600 mg zinc oxide/kg diet (CuZn), 9) NC + 5% resistant corn starch (RScn), and 10) NC + 0.05% β-glucan (BG) for 28 d. There was no impact of dietary treatment on BW gain or feed intake (P ≥ 0.22). Pigs fed diets containing SCF, CTsb, and RSpo resulted in microbial community differences compared to pigs fed the NC (P < 0.05). In EXP 2, 48 barrows (12.8 kg BW) were selected at the end of EXP 1 and fed the same dietary treatments they had previously received: 1) NC, 2) NC + 5% RScn, 3) NC + 5% SCF, and 4) NC + FAM for 8 d. There was no effect of feeding diets containing RScn, SCF, or FAM on in vivo intestinal permeability (P ≤ 0.21). Ileal or colon pH, concentrations of VFA did not differ due to dietary treatment (P ≥ 0.36), but pigs fed diets containing FAM resulted in a greater butyric acid concentration in the cecum compared to pigs fed the NC (P ≤ 0.05). In EXP 3, 156 pigs (6.11 kg BW) were placed into 52 pens with 3 pigs/pen and allotted to 1 of 4 dietary treatments arranged in a factorial manner: 1) NC, 2) NC + 5% RSpo, 3) NC + 0.30% FAM, and 4) NC + 5% RSpo + 0.30% FAM for 24 d. Feeding pigs diets containing RSpo did not affect BW gain (P = 0.91) while pigs fed diets containing FAM grew improved BW gain (P = 0.09). Colonic butyric acid concentrations were greater in pigs fed diets containing RSpo (P = 0.03), while pigs fed diets containing FAM exhibited reduced total VFA concentrations (P = 0.11). The results indicate that supplementing diets with digestively resistant but fermentable fibers, short- and medium-chain fatty acids, or antibiotics do not have a consistent effect, positive or negative, on markers of intestinal integrity or barrier function, intestinal VFA patterns, ATTD of energy and nutrients, or on pig performance.

Formulating Diets for Improved Health Status of Pigs: Current Knowledge and Perspectives

Our understanding of nutrition has been evolving to support both performance and immune status of pigs, particularly in disease-challenged animals which experience repartitioning of nutrients from growth towards the immune response. In this sense, it is critical to understand how stress may impact nutrient metabolism and the effects of nutritional interventions able to modulate organ (e.g., gastrointestinal tract) functionality and health. This will be pivotal in the development of effective diet formulation strategies in the context of improved animal performance and health. Therefore, this review will address qualitative and quantitative effects of immune system stimulation on voluntary feed intake and growth performance measurements in pigs. Due to the known repartitioning of nutrients, the effects of stimulating the immune system on nutrient requirements, stratified according to different challenge models, will be explored. Finally, different nutritional strategies (i.e., low protein, amino acid-supplemented diets; functional amino acid supplementation; dietary fiber level and source; diet complexity; organic acids; plant secondary metabolites) will be presented and discussed in the context of their possible role in enhancing the immune response and animal performance.

In Vitro Screening of Non-Antibiotic Components to Mitigate Intestinal Lesions Caused by Brachyspira hyodysenteriae, Lawsonia intracellularis and Salmonella enterica Serovar Typhimurium

Swine dysentery, ileitis, and porcine salmonellosis are production-limiting diseases of global importance for swine production. They are caused by infection with Brachyspira hyodysenteriae, Lawsonia intracellularis, and Salmonella enterica serovar Typhimurium, respectively. Currently, the prevention, treatment, and control of these diseases still relies on antimicrobials. The goal of this study was to evaluate the effectiveness of four commercially available non-antimicrobial compounds in preventing lesions caused by the bacteria cited above using an in vitro intestinal culture model. A total of five pigs per pathogen were used and multiple compounds were evaluated. For compound F (a fungal fermented rye), S (a blend of short and medium chain fatty acids), and P (a synergistic blend of short and medium chain fatty acids, including coated butyrates), a total of four explants/pig for each treatment were used, while for compound D (an extract of carob and thyme) only 12 explants/pig for each treatment were used. Explants were exposed to a combination of pathogen only (n = 4/compound/pig), compound only (n = 4/compound/pig), or pathogen and compound (n = 4/compound/pig) and sampled at two time-points. Histopathology and gene expression levels were evaluated to investigate the treatment effect on explants. Short and medium-chain fatty acids, and an extract of carob and thyme, was found to mitigate lesions due to B. hyodysenteriae exposure. A fungal fermented prebiotic increased healthy epithelial coverage when explants were exposed to L. intracellularis or S. Typhimurium. These findings represent a step towards finding alternatives to antimicrobials usage and control of swine dysentery, ileitis, and salmonellosis in pork production.

Impacts of feeding organic acid-based feed additives on diarrhea, performance, and fecal microbiome characteristics of pigs after weaning challenged with an enterotoxigenic strain of Escherichia coli

Post weaning diarrhea (PWD) caused by enterotoxigenic strains of E. coli (ETEC) remains a major problem in the industry, causing decreases in performance and survival of weaned pigs. Traditionally, antimicrobials have been used for its mitigation/control. This study tested the hypothesis that a combination of two organic acid (OA)-based commercial feed additives, Presan FX [an OA, medium-chain fatty acid (MCFA) and phenolic compound-based product] and Fysal MP (free and buffered OA based on formic acid), would reduce PWD and improve post-weaning performance in pigs challenged with an F4-ETEC. This combination was assessed against a Negative control diet without any feed additives and a diet containing amoxicillin. Combined with a reduction in temperature during the infection period, inoculation with F4-ETEC resulted in 81% of pigs developing diarrhea, but with no differences between treatments (P > 0.05). However, between days 14 to 20 of the study and due to colonization by Salmonella serovars, pigs fed the combination of Presan FX and Fysal MP showed less (P = 0.014) diarrhea commensurate with a lower (P = 0.018) proportion of Salmonella numbers relative to total bacterial numbers. This caused less (P = 0.049) therapeutic antibiotic administrations relative to the diet with amoxicillin during this time. The diversity of bacteria within amoxicillin-treated pigs was lower (P = 0.004) than the diversity in control or Presan FX + Fysal MP-treated pigs (P = 0.01). Pair-wise comparisons showed that amoxicillin-treated pigs had altered (P < 0.001) fecal microbial communities relative to both Presan FX + Fysal MP-treated pigs and control pigs. Amoxicillin-treated pigs were characterized by an increased abundance of bacterial families generally linked to inflammation and dysbiosis in the gastrointestinal tract (GIT), whereas Presan FX + Fysal MP-treated pigs had an increased abundance of bacterial families considered beneficial commensals for the GIT. Control pigs were characterized by an increased abundance of Spirochaetaceae associated with healthy piglets, as well as bacterial families associated with reduced feed intake and appetite. The combination of two OA-based feed additives did not reduce the incidence of F4 ETEC-associated diarrhea nor enhance performance. However, the combination markedly reduced diarrhea caused by Salmonella that occurred following the ETEC infection, commensurate with less therapeutic administrations relative to the diet with amoxicillin.

Fermented rye with Agaricus subrufescens and mannan-rich hydrolysate based feed additive to modulate post-weaning piglet immune response

BACKGROUND

The process of weaning in piglets is often associated with an increased inflammation response in the intestine and compromised intestinal integrity and morphology, favoring a delay in intestinal maturation and a predisposal to diseases. Research has shown the potential of different nutritional strategies to reduce the production of pro-inflammatory cytokines, with the main goal to manipulate health and performance of pigs. Promising examples of nutritional strategies are fungal fermented products and their derivatives which are described to contain several compounds that may play a role in gastrointestinal health and pathogenic bacteria control. Products from Agaricus subrufescens mushroom are reported to contain prophylactic and therapeutic properties including antimicrobial and immunomodulatory properties.

RESULTS

This study analysed the post-weaning immune status in intestinal tissue and blood of piglets, with the objective to evaluate the gastrointestinal health and immune modulation response induced by a blend of mannan-rich hydrolyzed copra meal and fermented rye with A. subrufescens. Intestinal histomorphology demonstrated a villus height reduction in jejunum and increase in ileum on day 15, while increased villous height in jejunum and ileum on day 30. The results showed that in post-weaning piglets, the feed additive stimulates an immunomodulation effect most evident at 15 days post-weaning, with significant lower expression of cytokines Interferon (IFN) γ, Interleukin (IL) 1α, IL-1β, IL-6, IL-8, IL-10 and Transforming Growth Factor (TGF) β in jejunum, accompanied with an increase in peripheral blood mononuclear cells (PBMC) cytokine gene expression of IL-1β, IL-6, IL-8, IL-10, IL-12p35 (IL-12α), IL-12p40 (IL-12β), Tumor Necrosis Factor (TNF) α, IFN-α, and TGF-β. In piglets fed the feed additive, the quantity of Immunoglobulin (Ig) A producing cells in jejunum, ileum was reduced on day 15 and 30 post-weaning, and on day 30 and 45 post-weaning in colon tissue. Natural Killer (NK) cells count in blood were increased on day 15 post-weaning in the piglets fed the feed additive.

CONCLUSION

This study implies the potential of the blend including mannan-rich hydrolyzed copra meal and fermented rye with A. subrufescens on immune modulation in the intestine of post-weaning piglets.

Salmonella Infection in Nursery Piglets and Its Role in the Spread of Salmonellosis to Further Production Periods

Few studies have focused on assessing Salmonella infection in the nursery and its role in further pig production periods. Mesenteric lymph nodes, intestinal content, and meat juice from 389 6-week-old male piglets intended for human consumption from five breeding farms and 191 pooled floor fecal samples from gilt development units (GDU) from the same farms were analyzed to estimate and characterize (by pulsed-field gel electrophoresis and antimicrobial resistance analyses) Salmonella infection. The prevalence of infection and shedding among piglets was 36.5% and 37.3%, respectively, shedding being significantly associated with infection (Odds Ratio = 12.7; CI 7.3-22.0). Salmonella Rissen; S. 4,[⁵],12:i:-; and S. Derby were the most common serotypes. A low level of Salmonella-specific maternal antibodies at the beginning of the nursery period suggested it was a period of high risk of infection. Resistance to 3rd- and 4th-generation cephalosporins was detected in piglet isolates although the piglets never received antibiotics, indicating they could be vectors of antimicrobial resistance. The same Salmonella clones were detected in piglet and GDU isolates, suggesting that infected piglets play a significant role in the infection of gilts and consequently of finishing pigs in the case of production farms. The control of Salmonella infection in nursery piglets may decrease the risk of abattoir and carcass contamination.

Antioxidant Activity of Flavonoids in LPS-Treated IPEC-J2 Porcine Intestinal Epithelial Cells and Their Antibacterial Effect against Bacteria of Swine Origin

Beneficial effects of flavonoids are widely known in human medicine, but less information is available about their veterinary usage. Based on their antioxidant and antibacterial activity, proanthocyanidins (PAs) and luteolin (LUT) might be used in the prevention and treatment of gastrointestinal infections in swine. In this study, in vitro beneficial effects of grape seed oligomeric proanthocyanidins (GSOPs) and LUT were investigated against bacterial endotoxin (LPS)-induced oxidative stress in IPEC-J2 porcine epithelial intestinal cells. Furthermore, antibacterial effects of GSOP and LUT were assessed against field isolates of Escherichia coli and Salmonella enterica ser. Typhimurium. Both GSOP and LUT were found to possess potent in vitro antioxidant activity in LPS-treated IPEC-J2 cells; furthermore, they showed a bacteriostatic effect against the tested bacterial strains of porcine origin. Both flavonoids seem to be effective in the protection of porcine intestinal epithelial cells against Gram-negative bacteria in vitro, but further in vivo studies are necessary to confirm these activities and to establish their optimal dosage regimen for future usage in veterinary practice.

Effect of a High Proportion of Rye in Compound Feed for Reduction of Salmonella Typhimurium in Experimentally Infected Young Pigs

Public health concerns and the potential for food-borne zoonotic transmission have made Salmonella a subject of surveillance programs in food-producing animals. Forty-two piglets (25 d of age and initially 7.48 kg) were used in a 28 d infection period to evaluate the effects of a high proportion of rye on reducing Salmonella Typhimurium. Piglets were divided into two diet groups: control diet (wheat 69%) and experimental diet (rye 69%). After a one-week adaptation period, all piglets were orally infected with Salmonella Typhimurium (10⁷ log CFU/mL; 2mL/pig). Salmonella in fecal shedding were evaluated at day 1, 3, 5, 7 and then weekly after infection. At the end of the experimental period (at day 28 after infection), the piglets were euthanized to sample feces, cecal digesta contents and ileocecal lymph nodes to determine the bacterial counts of Salmonella. The results suggest that the bacterial counts in the experimental group fed rye diets showed evidence of reducing Salmonella fecal shedding from day 14 onwards and decreasing the number of Salmonella in cecal digesta. However, the translocation of Salmonella in ileocecal lymph nodes was not affected. Furthermore, feed intake, weight gain and feed conversion did not differ between the groups (p > 0.05).

Pigs' Feed Fermentation Model with Antimicrobial Lactic Acid Bacteria Strains Combination by Changing Extruded Soya to Biomodified Local Feed Stock

Simple Summary

The world population is growing, and for this reason, it is very important to ensure increased agricultural production in a sustainable and eco-friendly manner. The aim of this study was to apply a combination of newly isolated antimicrobial characteristic possessing lactic acid bacteria (LAB) strains for local stock (rapeseed meal) fermentation and to evaluate the influence of changing an extruded soya to biomodified rapeseed meal in a feed recipe on piglet feces microbiota, health parameters, growth performance, and ammonia emission. The 36-day experiment was conducted using 25-day-old Large White/Norwegian Landrace (LW/NL) piglets, which were randomly distributed into two groups: a control group fed with a basal diet and a treated group fed with a fermented diet (500 g/kg of total feed). Changing from an extruded soya to fermented rapeseed meal led to desirable changes in piglets’ fecal microbiota (there was more than a four-fold higher Lactobacillus count compared to the control group). There was also a 20.6% reduction in ammonia emission in the treated group section. Finally, by changing from extruded soya to less expensive rapeseed meal and applying a fermentation model with selected LAB combination, piglets were fed without any undesirable changes in health and growth performance, as well as in a more sustainable manner.

Abstract

The aim of this study was to apply newly isolated antimicrobial characteristic possessing lactic acid bacteria (LAB) starters (Lactobacillus plantarum LUHS122, Lactobacillus casei LUHS210, Lactobacillus farraginis LUHS206, Pediococcus acidilactici LUHS29, L. plantarum LUHS135, and Lactobacillus uvarum LUHS245) for local stock (rapeseed meal) fermentation and to evaluate the influence of changing from an extruded soya to biomodified local stock in a feed recipe on piglets’ fecal microbiota, health parameters, growth performance, and ammonia emission. In addition, biomodified rapeseed meal characteristics (acidity and microbiological) were analyzed. The 36-day experiment was conducted using 25-day-old Large White/Norwegian Landrace (LW/NL) piglets, which were randomly distributed into two groups: a control group fed with basal diet and a treated group fed with fermented feed (500 g/kg of total feed). The study showed that the selected LAB starter combination can be recommended for rapeseed meal fermentation (viable LAB count in fermented feed 8.5 ± 0.1 log₁₀ CFU/g and pH 3.94 ± 0.04). At the beginning of the in vivo experiment, the microbial profiles in both piglet groups were very similar: The highest prevalence was Prevotella (34.6–38.2%) and Lactobacillus (24.3–29.7%). However, changing from an extruded soya to fermented rapeseed meal in the feed recipe led to desirable changes in piglets’ fecal microbiota. There was a more than four-fold higher Lactobacillus count compared to the control group. Furthermore, there was significantly lower ammonia emission (20.6% reduction) in the treated group section. Finally, by changing from an extruded soya to cheaper rapeseed meal and applying the fermentation model with the selected LAB combination, it is possible to feed piglets without any undesirable changes in health and growth performance, as well as in a more sustainable manner.