Post-weaning Diarrhoea Research Articles

Effect of dietary tall oil fatty acids and hydrolysed yeast in SNP2-positive and SNP2-negative piglets challenged with F4 enterotoxigenic Escherichia coli

Reduction of post-weaning diarrhoea caused by ETEC is a principal objective in pig farming in terms of welfare benefits. This study determined the effects of genetic susceptibility and dietary strategies targeting inflammation and fimbriae adherence on F4-ETEC shedding and diarrhoea in weaned piglets in an experimental challenge model. A DNA marker test targeting single nucleotide polymorphism 2 (SNP2) identified piglets as heterozygous (SNP2+, susceptible) or homozygous (SNP2-, resistant) to developing F4ac-ETEC diarrhoea. A total of 50 piglets, 25 SNP2+ and 25 SNP2-, were weaned at 30 days of age and equally distributed to different treatments (n = 10): Positive control (PC): piglets fed with a negative control diet and provided with colistin via drinking water; Negative control (NC): piglets fed with a negative control diet; Tall oil fatty acids (TOFA): piglets fed with a negative control diet + 1.0 g TOFA/kg feed; Yeast hydrolysate (YH): piglets fed with a negative control diet + 1.5 g YH/kg feed derived from Saccharomyces cerevisiae; and Combination (COM): piglets fed with a negative control diet + 1.0 g TOFA and 1.5 g YH/kg feed. On day 10 post-weaning, all piglets were infected with F4-ETEC by oral administration. Piglets fed with PC, TOFA, YH or COM had a lower faecal shedding of F4-ETEC than NC piglets (P < 0.001), which was also shorter in duration for PC and TOFA piglets than for NC piglets (P < 0.001). Piglets in PC, TOFA, YH and COM had a shorter diarrhoea duration versus NC when classified as SNP2+ (P = 0.02). Furthermore, PC, TOFA and YH piglets grew more than NC and COM piglets in the initial post-inoculation period (P < 0.001). In addition, the level of faecal F4-ETEC shedding and the percentage of pigs that developed F4-ETEC diarrhoea (72 vs. 32%, P < 0.01) following infection were higher, and the duration of F4-ETEC diarrhoea longer (2.6 vs. 0.6 days, P < 0.001), in SNP2+ piglets than in SNP2- piglets, and led to reduced growth performance (P = 0.03). In conclusion, piglets fed with TOFA, YH or their combination, irrespective of their SNP2 status, are more resilient to F4-ETEC infection. Moreover, SNP2+ piglets show a higher level of F4-ETEC shedding and diarrhoea prevalence than SNP2- piglets, confirming an association between SNP2 and F4ac-ETEC susceptibility.

Responses in weanling pigs fed low protein diets supplemented with dietary nucleotides.

Evidence suggests that nucleotide supplementation in diets improves intestinal development, immune function, and cell growth. Stressful events such as weaning in pigs may increase nucleotidedemand, making exogenous supplementation potentially beneficial. This study evaluated the effects of low-protein (LP) diets supplemented with dietary nucleotides on growth performance, postweaning diarrhea (PWD), nutrient digestibility, and blood metabolites. A total of 210 piglets were weaned at 21 d of age, allowing a 3-d adaptation to a common nursery diet. At 24 d, pigs were reweighed (6.02 ± 0.05kg) and allocated to 5 dietary treatments in a randomized complete block design to give 7 replicates per treatment (n = 6 piglets per replicate). The 5 dietary treatments included (i) a high protein positive control diet (PC) with 24% crude protein (CP); (ii) a low protein negative control (NC) with 16% CP; (iii) an NC diet with nucleotide supplementation at 1g/kg (NC01), 3g/kg (NC03), or 9g/kg (NC09). Diets were provided ad libitum for 35 d, and weekly feed intake (FI) and body weight (BW) were recorded. Blood samples were collected on day 32 and fecal samples were collected on days 33, 34, and 35 to determine serum metabolites and nutrient digestibility, respectively. Relative to PC, the NC diet had lower overall average daily gain (ADG) (343.5 vs. 305.5g/d), incidence of PWD (2.5 vs. 1.2 diarrhea score), and blood urea nitrogen (BUN) (11.3 vs. 3.4mg/dL); (P < 0.05, < 0.05, and < 0.0001, respectively). The nucleotide-supplemented diets, NC01, NC03, and NC09, had comparable (P > 0.05) overall ADG to the PC and decreased (P < 0.0001) BUN. Additionally, NC09 had decreased (P < 0.05) incidence of PWD compared to PC. The apparent total tract digestibility (ATTD) of nitrogen increased linearly (P < 0.05) with nucleotide supplementation, although reducing CP decreased (P < 0.05) serum glutathione and insulin-like growth factor-1 (IGF-1) concentrations. However, IGF-1 concentration was linearly increased (P < 0.05) with nucleotide supplementation. Results suggest that feeding LP diets supplemented with dietary nucleotides after weaning can increase ATTD of nitrogen and protein utilization, reduce the incidence of PWD, and increase serum IGF-1 concentration while partially ameliorating the negative effects of LP diets on growth performance.

Effects of early postnatal gastric and colonic microbiota transplantation on piglet gut health

BackgroundDiarrhea is a major cause of reduced growth and mortality in piglets during the suckling and weaning periods and poses a major threat to the global pig industry. Diarrhea and gut dysbiosis may in part be prevented via improved early postnatal microbial colonization of the gut. To secure better postnatal gut colonization, we hypothesized that transplantation of colonic or gastric content from healthy donors to newborn recipients would prevent diarrhea in the recipients in the post-weaning period. Our objective was to examine the impact of transplanting colonic or gastric content on health and growth parameters and paraclinical parameters in recipient single-housed piglets exposed to a weaning transition and challenged with enterotoxigenic Escherichia coli (ETEC).MethodsSeventy-two 1-day-old piglets were randomized to four groups: colonic microbiota transplantation (CMT, n = 18), colonic content filtrate transplantation (CcFT, n = 18), gastric microbiota transplantation (GMT, n = 18), or saline (CON, n = 18). Inoculations were given on d 2 and 3 of life, and all piglets were milk-fed until weaning (d 20) and shortly after challenged with ETEC (d 24). We assessed growth, diarrhea prevalence, ETEC concentration, organ weight, blood parameters, small intestinal morphology and histology, gut mucosal function, and microbiota composition and diversity.ResultsEpisodes of diarrhea were seen in all groups during both the milk- and the solid-feeding phase, possibly due to stress associated with single housing. However, CcFT showed lower diarrhea prevalence on d 27, 28, and 29 compared to CON (all P < 0.05). CcFT also showed a lower ETEC prevalence on d 27 (P < 0.05). CMT showed a higher alpha diversity and a difference in beta diversity compared to CON (P < 0.05). Growth and other paraclinical endpoints were similar across groups.ConclusionIn conclusion, only CcFT reduced ETEC-related post-weaning diarrhea. However, the protective effect was marginal, suggesting that higher doses, more effective modalities of administration, longer treatment periods, and better donor quality should be explored by future research to optimize the protective effects of transplantation.

Laminaria japonica Polyascchride Improves Protein Metabolism of Weaned Piglets

Post-weaning diarrhea is one of the most common diseases in piglets, which will seriously affect the growth performance of weaned piglets and may even cause their death. LJP has been proven to improve the growth performance of weaned piglets. Protein metabolism is very important for growth, but there is little research on protein metabolism in weaned piglets by LJP. The aim of this study was to evaluate the effect of supplementing different levels of LJP (0, 100, 200 and 400 mg/kg) in the diet on protein metabolism in weaned piglets. A total of 120 piglets with similar initial body wight (6.13±0.21 kg) and age (21±1 day) were randomly assigned into 4 groups, each group had 5 replicates of 6 piglets. Four different levels of LJP (0, 100, 200 and 400 mg/kg) were added to the feed of four groups of piglets and kept for 21 days. The results showed that the content of total serum proteins was significantly increased in piglets supplemented with 200 and 400 mg/kg LJP and the content of albumin was significantly increased in piglets supplemented with 400 mg/kg LJP (p less than 0.05), compared with the control group. In conclusion, the addition of 200 and 400 mg/kg of LJP to the ration increased protein content in the serum and contributed to the growth and health of weaned piglets.

Blend of natural and natural identical essential oil compounds as a strategy to improve the gut health of weaning pigs

Weaning is one of the most critical phases in pig’s life, often leading to postweaning diarrhoea (PWD). Zinc oxide (ZnO), at pharmacological doses, has been largely used to prevent PWD; however, due to antimicrobial co-resistant and environmental pollution issues, the EU banned its use in June 2022. Natural or natural identical components of essential oils and their mixture with organic acids are possible alternatives studied for their antimicrobial, anti-inflammatory and antioxidant abilities. This study aimed to evaluate the effect of two blends of natural or natural identical components of essential oils and organic acids compared to ZnO on health, performance, and gut health of weaned pigs. At weaning (d0), 96 piglets (7 058 ± 895 g) were assigned to one of four treatments balanced for BW and litter: CO (control treatment), ZnO (2 400 mg/kg ZnO from d0 to d14); Blend1 (cinnamaldehyde, ajowan and clove essential oils, 1 500 mg/kg feed); Blend2 (cinnamaldehyde, eugenol and short- and medium-chain fatty acids, 2 000 mg/kg feed). Pigs were weighed weekly until d35. Faeces were collected at d13 and d35 for microbiota (v3–v4 regions of the 16 s rRNA gene) and Escherichia coli (E. coli) count analysis. At d14 and d35, eight pigs/treatment were slaughtered; pH was recorded on intestinal contents and jejunal samples were collected for morphological and gene expression analysis. From d7–d14, the Blend2 had a lower average daily gain (ADG) than CO and ZnO (P < 0.05). ZnO and Blend1 never differed in ADG and feed intake. At d14, ZnO had a lower caecum pH than all other treatments. The CO treatment had a higher abundance of haemolytic E. coli than Blend1 (P = 0.01). At d13, the ZnO treatment had a lower alpha diversity (P < 0.01) and a different microbial beta diversity (P < 0.001) compared to the other treatments. At d13, the ZnO treatment was characterised by a higher abundance of Prevotellaceae_NK3B31_group (Linear Discriminant Analysis (LDA) score = 4.5, P = 0.011), Parabacteroides (LDA score = 4.5, P adj. = 0.005), the CO was characterised by Oscillospiraceae UCG-005 (LDA score = 4.3, P adj. = 0.005), Oscillospiraceae NK4A214_group (LDA score = 4.2, P adj. = 0.02), the Blend2 was characterised by Megasphaera (LDA score = 4.1, P adj. = 0.045), and Ruminococcus (LDA score = 3.9, P adj. = 0.015) and the Blend1 was characterised by Christensenellaceae_R-7_group (LDA score = 4.6, P adj. < 0.001) and Treponema (LDA score = 4.5, P adj. < 0.001). In conclusion, Blend1 allowed to maintain the gut health of postweaning piglets through modulation of the gut microbiome, the reduction of haemolytic E. coli while Blend2 did not help piglets.

PSIII-2 Pediococcus Acidilactici Demonstrates Probiotic Properties and Inhibits the Growth of Enterotoxigenic Escherichia Coli

Abstract Lactic acid bacteria are recognized to possess probiotic properties including modulating host physiology. Probiotics are used as direct-fed microbials in the swine industry to optimize pig performance and production efficiency. In the nursery, probiotics have been shown to mitigate post-weaning diarrhea caused by enterotoxigenic Escherichia coli (ETEC). Studies show beneficial effects of supplementing probiotics and the data were inconsistent. Microbial genome sequencing could help better define the mechanisms of probiotic mode of action and dose required to improve probiotic efficacy. The aim of this study was to determine if Pediococcus acidilactici PECh3A (PA) that has been genome sequenced for determining gut physiology mechanisms expresses probiotic properties in-vitro. The growth curve of PA was conducted to determine colony forming units (CFU)/mL concentrations in 2-hour intervals until plateau at 15 hours. Based on the results of the growth curve dose response analysis were performed for acid and bile tolerance and antimicrobial activity against ETEC (3030-2: K88ac LT and STb). Doses investigated were 1010, 109, and 108 CFU/mL. For the acid and bile tolerance experiment PA was grown to concentration 1010 CFU/mL and was centrifuged and inoculated in De Mab, Rogosa, and Sharpe broth (MRS Broth) at pH 2, 4, or 6.5 (control) or MRS ± 0.3% oxgall (wt/vol), respectively, and incubated for 4 h. Following the 4 h incubation samples were serially diluted, plated, and incubated at 37°C for 24 h to determine percent survival. Antimicrobial inhibition of ETEC was assessed by the agar zone of inhibition (ZOI) methods. PA was grown to previously defined CFU/mL concentrations and 100 µL of the culture and filtered supernatant were plated into wells on nutrient agar plates spread with 107 ETEC CFU/mL. ZOI were measured in mm. Data were analyzed according to a factorial design using PROC MIXED procedures in SAS. Survival in acidic media relative to control media was observed in all doses (108,109, and 1010) at pH 4 and minimally at pH 2 (81.8, 90.6, and 89.5% or 33.8, 28.0, and 0% ±7.7, respectively; P &amp;lt; 0.01). PA survival in 0.3% oxgall increased with increasing dose (74.3, 83.3, and 91.7% ±0.67; P &amp;lt; 0.01). PA culture exhibited antimicrobial activity against ETEC at all doses tested, and the PA filtered supernatant exhibited antimicrobial activity from 109 CFU/mL (4.260 mm ± 0.9437, P &amp;lt; 0.01). Taken together the findings indicate that PA PECh3A exhibits functional probiotic properties to potentially improve swine intestinal physiology. Further in vitro and in vivo experiments will access Pediococcus acidilactici PECh3A function and interaction within the host environment.

Easy and reliable assessment of the prevalence of porcine post-weaning diarrhoea.

Post-weaning diarrhoea is a condition of increasing importance due to recent restrictions and bans on the preventive use of antimicrobials and medicinal zinc oxide. For various purposes, it is valuable to monitor the occurrence of post-weaning diarrhoea. The aim of this paper was to propose a protocol for easy and reliable assessment of the prevalence of post-weaning diarrhoea within a section of pigs as an alternative to clinical examination of a random sample of pigs. Two datasets were collected in two different observational field investigations, including more than 4000 individual clinical examinations of newly weaned pigs. First we identified a clinical marker for post-weaning diarrhoea. Second, we drew samples by simulation from our two dataset using different simplified sampling strategies and compared these to conventional random sampling strategies. The prediction error for estimates of the diarrhoea prevalence within a section was compared for the different sampling strategies. The study showed that pigs with diarrhoea had an increased risk of displaying diarrheic soiling of the hind part as well as dull, long, and bristly hair coat, and possibly also hollow flanks and a suboptimal body condition score. Diarrheic soiling of the hind part was the best clinical predictor of diarrhoea; our best estimate of the diagnostic sensitivity was 76.1% (95% credible interval: 72.0, 79.8), and the specificity was 97.1% (95% credible interval: 96.5 0.97.7). Diarrheic soiling of the hind is only a valid clinical predictor of diarrhoea for the first 14 days after insertion into the nursery unit. The precision and accuracy of prevalence estimates were similar for haphazard sampling compared to random sampling of the pigs. Likewise, sampling from a restricted number of pens produced prediction errors similar to sampling across all pens. Yet, the study had limitations regarding sample sizes, and furthermore it is difficult to provide certainty for absence of effects. We recommend sampling pigs haphazardly within at least three randomly selected pens for post-weaning diarrhoea prevalence surveys in order to easily obtain a reliable prevalence estimate. Based on our findings, we conclude the paper by proposing a simple four-step protocol for surveys of the within-section prevalence of post-weaning diarrhoea.

The prebiotic potential of RS-3 preparations for pre- and post-weaning piglets

Piglets undergo stress during the weaning period, resulting in an imbalance in gut microbial composition and activity, and potentially post-weaning diarrhoea. Supporting maturation of gut microbiota is a strategy preparing piglets for weaning, and could be achieved by providing dietary fibres such as resistant starch (RS) in the creep feed. We investigated the prebiotic potential of four well-characterised retrograded starches (RS-3 preparations) for pre- and post-weaning piglets. These RS-3 preparations were in vitro fermented using pooled faecal inoculum of 3-week-old (pre-weaning) and 7-week-old (post-weaning) piglets. RS-3 preparations containing a high amount of digestible starch (≥ 75 %) were fully fermented by both faecal inocula within 48 h. Such substrates generated mostly butyrate when fermented by pre-weaning piglet faecal inoculum, whereas mostly propionate was found during fermentation by post-weaning inoculum. Bacterial genera Prevotella and Megasphaera increased in relative abundance after fermentation by both inocula, whereas Streptococcus and Selenomonas increased in relative abundance only when fermented by pre-weaning or post-weaning piglet faecal inocula, respectively. Highly resistant or so-called intrinsic RS-3 (≥ 80 % RS) was hardly degraded by pre-weaning inoculum, whereas it was slowly fermented by post-weaning piglet faecal microbiota, leading to an increase in relative abundance of specific Prevotella and Roseburia phylotypes (amplicon sequence variants). This study shows that partially resistant RS-3 preparations might be beneficial dietary fibres for pre-weaning piglets by promoting short-chain fatty acids production, while intrinsic RS-3 was hardly fermentable. Intrinsic RS-3 substrates might have prebiotic potential for post-weaning piglets by stimulating potential health-beneficial Prevotella and Roseburia.

PSVI-8 Effects of Dietary Supplementation of Pediococcus Pentosaceus Strains Isolated from White Kimchi in Weaned Piglet Challenged with Escherichia Coli and Salmonella Typhimurium

Abstract Escherichia coli and Salmonella typhimurium infections in pigs are major source associated with enteric disease such as post-weaning diarrhea. Lactic acid bacteria, one of the most essential probiotics, can colonize the digestive tract and increase nutritional digestion and maintain the stability of the intestinal flora. The aim of this study was to investigate the effects of Pediococcus pentosaceus in weaned piglets challenged with pathogen bacteria. In exp.1, 90 weaned piglets with initial body weights of 8.53 ± 0. 34 kg were assigned to 15 treatments for 2 weeks. The experiments were conducted two trials in a 2 × 5 factorial arrangement of treatments consisting of two levels of challenge (challenge and non-challenge) with E.coli and Salmonella typhimurium, respectively and five levels of probiotics (Control, Lactobacillus plantarum, Pediococcus pentosaceus SMFM2016-WK1, Pediococcus acidilactici K, Lactobacillus reuteri PF30). In exp.2 a total of 30 weaned pigs (initial body weight of 9.84 ± 0. 85kg) were used in 4 weeks experiment. Pigs were allocated to 5 groups in a randomized complete way with 2 pens per group and 3 pigs per pen. Supplementation of Lactobacillus plantarum and Pediococcus pentosaceus SMFM2016-WK1 improved (P &amp;lt; 0.05) growth performance, intestinal pathogen bacteria counts compared with control group in exp.1. Also, Lactobacillus plantarum and Pediococcus pentosaceus SMFM2016-WK1 improved (P &amp;lt; 0.05) fecal noxious odor, diarrhea incidence and digestibility of crude protein and gross energy compared with control group in exp.2. In conclusion, supplementation of 38W strains isolated from white kimchi can act as probiotics by inhibiting E.coli and Salmonella typhimurium.

277 Effect of Mode of Delivery of Fecal Microbiota Transplants on Growth Performance and Gut Microbiome in Weaning Piglets

Abstract Weaning is one of the most stressful events for piglets, due to diet change from sow milk to grain-based feed. This diet change causes turnover of the gut microbial which can allow proliferation of pathogens leading to diarrhea. Antibiotics are administered to treat or prevent post-weaning diarrhea (PWD). Increased occurrence of antimicrobial resistance has increased incentives to develop viable antibiotic alternatives. Previous studies have shown that fecal microbiota transplant (FMT) reduced diarrhea incidence and improved body weight gain in piglets. However, one barrier to FMT adoption in swine production is that FMT are generally given via oral gavage, which is difficult and labor intensive for large swine operations. For FMT to be a viable option in swine management, a simple method is needed to administer the transplant. The objective of this study was to determine the effect of three methods of FMT administration (oral, rectal and lyophilized in-feed) on growth performance, diarrhea incidence and gut microbiome. We hypothesize that FMT (in-feed and rectal) will increase colonization efficiency, improve growth performance and reduce diarrhea incidence compared with control. Weaned male piglets (n = 40) were allotted to 4 treatments at 10 piglets per treatment (no FMT - Control, Oral gavage - FMT1, rectal gavage - FMT2 and lyophilized in-feed – FMT3). Feces from 12-week-old pigs, screened for pathogens, was donor material. The study lasted nine days and FMT was for five days. Diarrhea incidences and body weight were observed for the first week. Fecal samples were collected on days 0, 2, 5 and 7. Five piglets per group were sacrificed on day 4 and the remaining on day 8. Cecal and colon contents were collected from the sacrificed piglets. DNA was extracted from fecal and digesta samples and 16S rRNA gene libraries (V4 region) were prepared for bacterial community analysis. Data were analyzed with one-way ANOVA in R. All FMT groups had significantly greater body weight on day 3 (P &amp;lt; 0.05) and average daily gain between day 0 – 3 (P &amp;lt; 0.05) compared with control but there was no difference between FMT groups. There was no effect of FMT on average daily feed intake and diarrhea incidence. Only FMT3 had greater alpha diversity (Observed features and Faith’s phylogenetic diversity) on day 5 (P &amp;lt; 0.05) compared with control, but there was no difference in beta diversity between FMT groups. There was decreased abundance of 27 ASVs (amplicon sequence variant) and increased abundance of 30 ASVs in increased in FMT3 compared with control on day 5. In conclusion, the three FMT groups has similar colonization pattern but there was no difference in diarrhea incidence. FMT3 (lyophilized in-feed) altered overall community structure of piglets and modulated individual taxa.

314 Maxwell Lecture: Role of Amino Acids and Protein in Health-Challenged Nursery Pigs

Abstract The post-weaning period is a critical time in the life of a pig with both short- and long-term consequences for productivity and health. Nutrition has a vital role in this transition period and, as with swine production as a whole, the focus is largely on maximizing growth performance. However, feeding programs also need to account for immature and developing gastrointestinal and immune systems in the newly-weaned pig. In examining the impact of nutrition on gastrointestinal and immune health, it has become evident that protein and amino acids have a vital role. While protein and amino acids are needed to meet requirements for growth, excess protein can predispose pigs to post-weaning diarrhea, thought to be the result of fermentation of undigested protein and proliferation of enteric pathogens. In addition, the source of protein may also have a significant impact on performance and health of nursery pigs. Traditionally, amino acid requirements, and thus dietary inclusion, have been based on maximizing growth performance. It has become evident that the requirements of some amino acids may differ when based on development of the gastrointestinal tract and during times of immune stimulation, such as during disease challenge. The inclusion of some amino acids, such as methionine, threonine, and tryptophan, above the requirements for growth have been shown to improve performance, intestinal health, and immune status in weaned pigs under enteric pathogen challenge. Nursery diet formulations should account for the role of nutrients not only for maximizing growth performance but optimizing gastrointestinal health and immune status including adjustments to protein content and source and amino acid requirements.

PSII-15 Effect of Low Protein Diets Fed to Weanling Pigs on Growth Performance, Fecal Score, and Carcass Characteristics

Abstract Two experiments were conducted to test the hypothesis that feeding low protein diets to weanling pigs reduces diarrhea with no effects on growth performance from wean to finish or on carcass characteristics. In Exp. 1, 160 pigs (BW: 6.88 ± 0.36 kg) were allotted to 5 diets with 4 pigs/pen and 8 pens/diet. Five phase 1 diets were fed from d 1 to 14 and included the positive control (PC; CP = 23%) with an antibiotic growth promoter (AGP), the negative control (NC; CP = 23%) without the AGP, the NC containing 25% rolled oats (RO), and 2 diets containing 17% CP and 0 or 25% RO. Phase 2 diets were fed from d 14 to 35 and included the PC (CP =21 %) with an AGP, the NC (CP = 21%) without the AGP, the NC containing 20% RO, and 2 diets containing 19% CP and 0 or 25% RO. The statistical model included diet as fixed effect and replicate as random effect. Results from Exp. 1 indicated that pigs fed the 17% CP diet without RO had decreased (P &amp;lt; 0.05) diarrhea scores compared with the NC diet containing RO. Pigs fed the 17% CP diet containing RO had reduced (P &amp;lt; 0.05) G:F compared with the NC diet, but there was no difference among pigs fed the other 4 diets. In Exp. 2, 160 pigs (BW: 6.29 ± 1.00 kg) were allotted to 4 diets with 5 pigs/pen and 8 pens/diet in a wean to finish experiment with 6 phases. Phase 1 and 2 diets were fed for 14 d each, phase 3 was fed for 18 d, and phase 4, 5, and 6 diets were each fed for 35 d. In Phase 1, four diets included the PC diet (CP = 23%) with an AGP, the NC diet (CP = 23%) without the AGP, and 2 diets containing 19% CP or 17% CP and no AGP. In Phase 2, four diets included the PC diet (CP = 22%) with an AGP, the NC diet (CP = 22%) without the AGP, and 2 diets containing 20% CP or 19% CP and no AGP. All pigs were fed common conventional diets from Phase 3 to market. Data were analyzed as in Exp 1. Overall results from Exp. 2 indicated that there were no differences among treatments in the growth performance and carcass characteristics of pigs from wean to finish. In conclusion, feeding low protein diets to weanling pigs reduced post-weaning diarrhea and may replace antibiotic growth promoters without affecting growth performance or carcass characteristics at the time of marketing of pigs although slight reductions in growth performance in the nursery phase may be observed.

Structure, function, and potential application of F18 in vaccine development

Post-weaning diarrhea is one of the most common diseases in pigs, affecting pigs in the first two weeks after weaning, causing significant economic losses. The main cause of this disease is Enterotoxigenic Escherichia coli (ETEC), which is characterized by two pathogenic factors: fimbriae and enterotoxins. These fimbriae are considered to mediate bacterial adhesion through binding to the receptor present in the pig intestine. Several studies indicate that F4 and F18 fimbriae account for a high percentage of the fimbriae in ETEC and are detected in most of the isolated ETEC strains. Currently, oral vaccines are a potential preventive measure used with the ability to generate IgA, stimulate the mucosal immune system, and be widely noticed by researchers. However, the vaccines are only effective against ETEC-F4 and less effective against ETEC-F18, so more research is needed to improve the effectiveness of ETEC-F18 vaccines in the future. In this review, we presented the structure, function, and potential application of the F18 in vaccine development.

Pre-Treatment with Bromelain Prevents Intestinal Dysbiosis in Pigs with Post-Weaning Diarrhea, without Increasing Antimicrobial Resistance in Escherichia coli.

Pigs are especially vulnerable to intestinal pathogens and dysbiosis in the first two weeks after weaning. Infection with enterotoxigenic strains of Escherichia coli (ETEC) in combination with poor nutrition and hygiene can lead to diarrhea, poor growth and increased mortality. While neomycin and zinc oxide can prevent post-weaning diarrhea (PWD), their broad-spectrum activity also kills commensal microbiota and can lead to the emergence of heavy metal and antimicrobial resistance. Bromelain prevents attachment of F4 ETEC to intestinal enterocytes by cleaving the host receptor. In controlled environmental facilities, weaned pigs treated with either therapeutic levels of neomycin sulfate, zinc oxide, bromelain or non-treated were monitored for diarrhea, weight gain, feed intake, feed efficiency, excretion of F4 ETEC, changes to their intestinal microbiomes and antimicrobial resistance in E. coli. The treatment effects were evaluated at weaning, during two weeks of treatment and for three weeks after treatments ceased. Minimal clinical signs of PWD were observed, except in zinc-treated pigs post treatment. Intestinal dysbiosis was observed in response to diarrhea and in pigs treated with both neomycin and zinc. Antimicrobial resistance increased in commensal E. coli isolated from neomycin- and zinc-treated pigs. In contrast, bromelain controlled PWD and prevented intestinal dysbiosis without inducing antimicrobial resistance.

EFFECT OF Vernonia Amygdalina LEAF MEAL EXTRACT IN DRINKING WATER ON POST-WEANING DIARRHEA OCCURRENCE IN PIGLETS

This study was aimed at determining the effect of Vernonia amygdalina leaf meal (VALM) extract in drinking water on the faecal microbial load on post-weaning diarrhea occurrence in piglets using different agar. Forty-five piglets of Large white X Duroc breed were given Vernonia amygdalina (VA) through water infusion. Three levels of 0.0g, 1.2g, and 2.4g of VA per 1000ml of clean drinking water designated as T1, T2, and T3 were used. Nine piglets weaned at different ages of 2nd, 3rd, 4th, 5th, and 6th week of age were randomly allotted to three treatments with each treatment replicated three times with a piglet per replicate in a completely randomized design. The different agar used are Macconkey Agar, Eosin Methylene Blue (EMB) Agar, and Nutrient Agar. These agars were used for 4days each to determine the faecal microbial load. The experiment lasted 28 days. Results showed that the bitter leaf contain high Alkaloids, medium Tannins, Saponins Flavonoids, and low amounts of Terpenoids and Phenols while Cardiac Glycosides were not determined. Bitter leaf showed the power of antibacterial activity for the reduction of faecal microbial load. Bitter leaf as a feed additive in the drinking water of piglets caused a significant (P&lt;0.05) reduction in the faecal microbial load for piglets given 1.2g and 2.4g of VA per 1000ml of drinking water. It can be concluded that bitter leaf extract in drinking water can be used as phyto-additive for piglets to reduce faecal microbial load.&#x0D;

Feasibility of crude F4 fimbriae extract as a vaccine candidate for preventing Escherichia coli-induced diarrhea in piglets.

Enterotoxigenic Escherichia coli (ETEC) poses a substantial risk of neonatal diarrhea and post-weaning diarrhea among piglets, with F4+ ETEC strains emerging as a particularly challenging issue within the pig farming industry. This study aimed to introduce a straightforward approach for generating a crude extract of F4 fimbriae that shows promise as an antigenic determinant for potential vaccination strategies. A crude F4 fimbriae extract was obtained from F4+ ETEC using a combination of heat shock and homogenization techniques. Subsequently, three 4-week-old piglets were immunized with a primary dose of 150 μg and a booster dose 2 weeks later. Blood samples were collected to evaluate the level of serum F4-specific antibodies using an enzyme-linked immunosorbent assay. Analysis using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and liquid chromatography tandem-mass spectrometry techniques unveiled crucial insights into the composition of the crude F4 fimbriae extract. Notably, a distinct prominent band (~24 kDa) was identified, corresponding to the size of FaeG, the major subunit of F4 fimbriae. Regarding antibody response, there was a remarkable disparity between the levels of serum immunoglobulin (Ig)G and IgA antibodies targeting F4 compared with other E. coli strains (F18+ ETEC, F41+ ETEC, and F4-F18-F41- EC), as well as with the unvaccinated control group (p < 0.01). Specifically, the levels of IgG antibodies against other E. coli strains were also significantly higher than those observed in the unvaccinated control group (p < 0.05). Our findings suggest that the crude F4 fimbriae extracts obtained using our simple extraction method induce specific immune responses against F4+ E. coli and stimulate cross-immunity against other E. coli strains. Therefore, our method shows potential for use in future vaccine development against diarrhea in pigs caused by E. coli.

Evaluation of the efficacy of two postweaning colibacillosis vaccines in a field herd with PRRS circulation during postweaning stage

Postweaning diarrhea (PWD) and PRRS are two major concerns in swine production, which association has not been consistently explored. In the current scenario of restrictions in the use of antibiotics and ZnO, vaccination is more relevant to control PWD, but PRRS virus circulation may compromise the immune protection conferred by postweaning colibacillosis vaccines. We evaluated the efficacy of two postweaning colibacillosis vaccines (parenteral and oral) in a commercial herd affected by an outbreak of PWD and with PRRS circulation in postweaning. Five groups were studied during the postweaning period: one control (Group 1) and four vaccinated: two with each postweaning colibacillosis vaccine administered alone (Groups 2 and 3) or with sow vaccination against PRRS (Groups 4 and 5). We evaluated the effects on piglet weight, average daily weight gain and in the percentage of piglets with diarrhea, its duration, lethality and mortality. PRRS viremia and anti-PRRS antibodies were evaluated by qPCR and ELISA. Regarding control group, colibacillosis vaccination generally improved most of the measured parameters; but significant improvements were only observed in Groups 4 and 5 (p < 0.05). Moreover, cases of diarrhea occurred at different ages: in Groups 2 and 3 the peak of cases occurred just after ZnO was removed from the feed compared to Group 1, while in Groups 4 and 5 no peak was observed. This suggests that postweaning colibacillosis vaccination may be compromised by the PRRS circulation. In PRRS endemic herds an effective protection against PWD through vaccination may require PRRS vaccination to obtain a better performance.

33. Early life postnatal faecal filtrate transplantation in pigs reduces post-weaning diarrhoea and increases survival

33. Early life postnatal faecal filtrate transplantation in pigs reduces post-weaning diarrhoea and increases survival

75 (P7-7). Acid-treating low protein piglet diets reduces the incidence of post-weaning diarrhoea without compromising growth performance

75 (P7-7). Acid-treating low protein piglet diets reduces the incidence of post-weaning diarrhoea without compromising growth performance

Developing and Evaluating a Weaned Piglet Model of Enterotoxigenic Escherichia Coli Infection

Enterotoxigenic Escherichia Coli (ETEC) remains the main pathogen associated with post-weaning diarrhea in piglets. Here, we introduce a reliable method to develop an ETEC-infected weaned piglet model. For the first 24 h post-birth, neonatal piglets were separated from dams so that they did not receive colostrum. Afterwards, piglets were returned to the care of their mothers, until weaning (21-day-old). On days 25, 26 and 27 post-birth, piglets were orally challenged with 1011 Colony-Forming Units (CFU) of virulent ETEC strain incubated in colony-forming antigen medium and delivered in chitosan-coated capsules. In all infected piglets, severe diarrhea and typical body weight loss were observed post-infection. To simplify the work, for the newly developed method, the number of challenging ETEC cells was lowered to 1010 CFU/head and the incubation medium was changed to tryptic soy. These modifications influenced neither the diarrheal defecation ratio nor the body weight loss in piglets. To induce experimentally ETEC infection in future work, we recommend that 1010 CFU/head of ETEC cell grown in tryptic soy broth be delivered in chitosan-coated capsules to colostrum restricted piglets, because this methodology stably caused 100% diarrheal defecation and growth reduction.