Dietary fermented soybean meal replacement alleviates diarrhea in weaned piglets challenged with enterotoxigenic Escherichia coli K88 by modulating inflammatory cytokine levels and cecal microbiota composition.

BACKGROUND: Impaired gut microbiota leads to pathogenic bacteria infection, pro-inflammatory response and post-weaning diarrhea. Enterotoxigenic Escherichia coli (ETEC) K88 is a major cause of post-weaning diarrhea in weaned piglets. Fermented soybean meal (FSBM) could relieve diarrhea, alleviate inflammatory response, and modulate gut microbiota of weaned piglets. We used ETEC K88-challenged weaned piglet model to investigate the effects of FSBM on the growth performance, inflammatory response and cecal microbiota. Twenty-four crossbred piglets (6.8 ± 0.5 kg; 21 ± 2 days of age) were allotted into 2 treatment fed the diets with or without FSBM (6% at the expense of soybean meal). Six weaned piglets in each diet treatment were challenged by ETEC K88 (1 × 109 CFU/piglets) on day 15. The experimental period lasted for 20 days. RESULTS: The ETEC K88 challenge decreased (p < 0.05) fecal consistency and plasma interleukin-10 (IL-10) concentration, while increased (p < 0.05) average daily feed intake (ADFI) and plasma tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß) and interleukin 6 (IL-6) concentrations. After ETEC K88 challenge, dietary FSBM replacement increased (p < 0.05) final body weight (BW), average daily gain (ADG), ADFI, and fecal consistency, but decreased feed conversion ratio (FCR). The plasma IL-10 concentration of weaned piglets fed FSBM was higher (p < 0.05), while IL-1ß, IL-6 and TNF-α concentrations were lower (p < 0.05). Dietary FSBM replacement attenuated the increase of plasma TNF-α concentration and the decrease of ADG induced by ETEC K88 challenge (p < 0.05). High-throughput sequencing of 16S rRNA gene V4 region of cecal microbiota revealed that ETEC K88 challenge increased (p < 0.05) Campylobacter relative abundance on genus level. Dietary FSBM replacement resulted in higher (p < 0.05) relative abundances of Bacteroidetes and Prevotellaceae_NK3B31_group, and lower (p < 0.05) relative abundances of Proteobacteria and Actinobacillus. Furthermore, dietary FSBM replacement relieved the increase of Escherichia-Shigella relative abundance in weaned piglets challenged by ETEC K88 (p < 0.05). CONCLUSIONS: Dietary FSBM replacement improved growth performance and alleviated the diarrhea of weaned piglets challenged with ETEC K88, which could be due to modulation of cecal microbiota composition and down-regulation of inflammatory cytokines production.

Duan-Nai-An, A Yeast Probiotic, Improves Intestinal Mucosa Integrity and Immune Function in Weaned Piglets.

Post-weaning diarrhea commonly occurs in piglets and results in significant economic loss to swine producers. Non-antibiotic measures for managing post-weaning diarrhea are critically needed. Duan-Nai-An, a probiotic produced from the yeast fermentation of egg whites, was previously shown to optimize intestinal flora and reduce the incidence of clinical diarrhea in weaning piglets. To study the effects of Duan-Nai-An on mucosal integrity and immunity in pig intestine, we examined the microstructure and ultrastructure of the intestines of weaned pigs with or without Duan-Nai-An as a feed supplement. The piglets of the Duan-Nai-An-fed group developed intestines with intact columnar epithelia covered by tightly packed microvilli on the apical surface. However, piglets of the control group (no supplement) showed villous atrophy and thinning, microvillus slough, and in the severe cases, damage of intestinal epithelia and exposure of the underlying lamina propria. Moreover, piglets of the Duan-Nai-An-fed group showed apparent plasmocyte hyperplasia, increased lymphoid nodule numbers, well-developed Peyer's Patchs, and apparent germinal centers. The lymphoid tissues of the control group were far less developed, showing lymph node atrophy, lymphocyte reduction, degeneration, and necrosis. These results indicate that Duan-Nai-An improves the development of the intestinal structures and lymphoid tissues and promotes intestinal health in weaned piglets.

Effects of feeding diets containing essential oils and betaine to heat-stressed growing-finishing pigs.

This study was to evaluate the effects of dietary essential oils (EO) and betaine on growth performance, nutrient digestibility and serum hormones in growing-finishing pigs under heat stress conditions. A total of 96 crossed pigs [(Landrace × Yorkshire) × Duroc] with an initial body weight (BW) of 24.7 ± 0.27 kg were used in an 18-week trial. Pigs were randomly allocated to four treatments according to BW and gender. There were six replication pens in each treatment, with four pigs (two barrows and two gilts) per pen. Treatment groups were: (1) control group (CON), basal diet + 23°C for 24 h; (2) heat stress group (HC) with basal diet + 37°C for 9 h, 23°C for 15 h; (3) group HEO, HC with 0.01% EO; (4) group HBE, HC with 0.1% betaine. During the overall period, groups HEO and HBE had higher (p < 0.05) average daily gain than group HC. At week 6, group HC had a lower apparent total tract digestibility (ATTD) of dry matter (DM) (p < 0.05), but at week 12, this group had lower ATTD of DM, nitrogen and gross energy than group HEO (p < 0.05). At week 12 and 18, dietary EO decreased (p < 0.05) serum cortisol and norepinephrine concentration. At week 18, dietary EO and betaine decreased (p < 0.05) epinephrine concentration. Conclusively, dietary EO may be a potential nutritional strategy to alleviate heat stress in growing-finishing pigs.

Young Pigs Consuming Lysozyme Transgenic Goat Milk Are Protected from Clinical Symptoms of Enterotoxigenic Escherichia coli Infection.

Background: Diarrheal diseases in infancy and childhood are responsible for substantial morbidity and mortality in developing nations. Lysozyme, an antimicrobial component of human milk, is thought to play a role in establishing a healthy intestinal microbiota and immune system. Consumption of breast milk has been shown to prevent intestinal infections and is a recommended treatment for infants with diarrhea.Objective: This study aimed to examine the ability of lysozyme-rich goat milk to prevent intestinal infection.Methods: Six-week-old Hampshire-Yorkshire pigs were assigned to treatment groups balanced for weight, sex, and litter and were fed milk from nontransgenic control goats (GM group) or human lysozyme transgenic goats (hLZM group) for 2 wk before they were challenged with porcine-specific enterotoxigenic Escherichia coli (ETEC). Fecal consistency, complete blood counts, intestinal histology, and microbial populations were evaluated.Results: Pigs in the hLZM group had less severe diarrhea than did GM pigs at 24 and 48 h after ETEC infection (P = 0.01 and 0.05, respectively), indicating a less severe clinical disease state. Relative to baseline, postmilk hLZM pigs had 19.9% and 137% enrichment in fecal Bacteroidetes (P = 0.028) and Paraprevotellaceae (P = 0.003), respectively, and a 93.8% reduction in Enterobacteriaceae (P = 0.007), whereas GM pigs had a 60.9% decrease in Lactobacillales (P = 0.003) and an 83.3% enrichment in Burkholderiales (P = 0.010). After ETEC infection, hLZM pigs tended to have lower amounts (68.7% less) of fecal Enterobacteriaceae than did GM pigs (P = 0.058). There were 83.1% fewer bacteria translocated into the mesenteric lymph nodes of hLZM pigs than into those of GM pigs (P = 0.039), and hLZM pigs had 34% lower mucin 1 and 61% higher tumor necrosis factor-α expression in the ileum than did GM pigs (P = 0.046 and 0.034, respectively).Conclusion: Results of this study indicate that human lysozyme milk consumption before and during ETEC infection has a positive effect on clinical disease, intestinal mucosa, and gut microbiota in young pigs.

Effect of feeding sodium butyrate in the late finishing period on Salmonella carriage, seroprevalence, and growth of finishing pigs.

Pork is an important source of human salmonellosis and low-cost on-farm control measures may provide a useful element in reducing the prevalence of this pathogen in food. This study investigated the effectiveness of dietary supplementation with sodium butyrate administered to finisher pigs for ∼4-weeks prior to slaughter to control Salmonella shedding on highly contaminated farms. Two trials (A and B) were conducted on two commercial pig farms, which had a history of high Salmonella seroprevalence. In both trials, pens (14 pens of 12 pigs/pen in Trial A and 12 pens of 12-17 pigs/pen in Trial B) were randomly assigned to a control (finisher feed without additive) or a treatment group (the same feed with 3kg sodium butyrate/t) for 24-28days, depending on the trial. Faeces were collected from each pig on days 0, 12 and 24/28, and blood, caecal digesta and ileocaecal/mesenteric lymph nodes were collected from the slaughterhouse. Pigs were weighed at the start and end of the trials, feed intake was recorded, and carcass quality parameters were recorded at slaughter. In Trial A, Salmonella shedding was reduced in the treatment compared to the control group at the end of the trial (30% versus 57% probability of detecting Salmonella in faeces, respectively; p<0.001). This reflected the serology results, with detection of a lower seroprevalence in the treatment compared to the control group using the 20% optical density cut-off (69.5% versus 89%; p=0.001). However, no effect on faecal shedding or seroprevalance was observed in Trial B, which may be explained by the detection of a concomitant infection with Lawsonia intracellularis. No significant differences in Salmonella recovery rates were observed in the caecal digesta or lymph nodes in either trial. Furthermore, feed intake, weight gain, and feed conversion efficiency (FCE) did not differ between groups (p>0.05) in either trial. Numerical improvements in weight gain and FCE were found with sodium butyrate treatment, which gave a cost benefit of €0.04/kg of live-weight gain. Overall, results suggest that strategic feeding of sodium butyrate, at 3kg/t of feed, to finishing pigs for 24-28days prior to slaughter was effective in reducing Salmonella shedding and seroprevalance but perhaps only in the absence of co-infection with other pathogens. However, sodium butyrate supplementation at this rate did not influence intestinal carriage, nor did it reduce seroprevalence to below the cut-off used for the high Salmonella risk category in Ireland (50%), or significantly improve growth performance.

Reduction of subclinical Salmonella infection in fattening pigs after dietary supplementation with a ß-galactomannan oligosaccharide.

AIMS: To assess the efficacy of a ß-galactomannan oligosaccharide (ß-GMOS) for the control of Salmonella infection in fattening pigs. METHODS AND RESULTS: Three different doses (0.5, 3 and 2 kg ß-GMOS per ton of feed) were used during the entire period of growing in three similar and independent field trials carried out in a small fattening unit (≈ 100 pigs). Treatment was randomly assigned to half of the pens. Individual serum samples (20-25 per group) were collected at different times during the fattening period and a similar number of faecal samples during the fattening period and at slaughter. In addition, mesenteric lymph nodes were collected at slaughter. Herdcheck(®) Swine Salmonella ELISA was used for serological analyses, the ISO 6579:2002/Amd 1 : 2007 for bacteriology and the PFGE for molecular characterization of Salmonella strains. The addition of ≥ 2 kg t(-1) of ß-GMOS to the pig diet during the entire fattening period was associated with a reduction in Salmonella prevalence, shedding and seroconversion. CONCLUSIONS: Feed supplementation with ß-GMOS may be a useful complementary tool for the control of salmonellosis in fattening pigs. SIGNIFICANCE AND IMPACT OF THE STUDY: ß-GMOS may be a complementary way of reducing Salmonella shedding and infection in fattening pigs.

Investigation into in vitro and in vivo models using intestinal epithelial IPEC-J2 cells and Caenorhabditis elegans for selecting probiotic candidates to control porcine enterotoxigenic Escherichia coli.

AIMS: To identify a fast, economic and reliable method for preselecting lactic acid-producing bacterial (LAB) isolates to control enterotoxigenic Escherichia coli (ETEC). METHODS AND RESULTS: Two assays with porcine intestinal epithelial IPEC-J2 cells or Caenorhabditis elegans for selecting effective probiotic candidates were compared. Both assays were based on measuring death of cells or worms caused by ETEC strain JG280. Six of 13 LAB isolates showed ≥50% protection in each assay, among which only four isolates (≥50% protection) were consistently selected by both assays. Isolate CL9 (Lactobacillus reuteri) was further studied. It reduced gene expression of estA, estB and elt in JG280 in both assays. Furthermore, the isolate protected IPEC-J2 and C. elegans from cell and worm death caused by STa, STb or LT enterotoxin expressed in E. coli DH5α. CL9 also promoted host defensive responses by decreasing IL-8 and increasing IL-10 production in IPEC-J2 cells and expression of antimicrobial peptide genes clec-60, clec-85 in C. elegans. CONCLUSIONS: Caenorhabditis elegans is useful for preselecting probiotic candidates to control ETEC after initial screening with IPEC-J2 cells. SIGNIFICANCE AND IMPACT OF THE STUDY: A combination of IPEC-J2 cell and C. elegans assays can improve the effectiveness in preselecting probiotic candidates.

Dietary N-Carbamylglutamate Supplementation Boosts Intestinal Mucosal Immunity in Escherichia coli Challenged Piglets.

N-carbamylglutamate (NCG) has been shown to enhance performance in neonatal piglets. However, few studies have demonstrated the effect of NCG on the intestinal mucosal barrier. This study was conducted to determine the effects of dietary NCG supplementation on intestinal mucosal immunity in neonatal piglets after an Escherichia coli (E. coli) challenge. New-born piglets (4 d old) were assigned randomly to one of four treatments (n = 7), including (I) sham challenge, (II) sham challenge +50 mg/kg NCG, (III) E. coli challenge, and (IV) E. coli challenge +50 mg/kg NCG. On d 8, pigs in the E. coli challenge groups (III and IV) were orally challenged with 5 mL of E. coli K88 (10(8) CFU/mL), whereas pigs in the sham challenge groups (I and II) were orally dosed with an equal volume of water. On d 13, all piglets were sacrificed, and samples were collected and examined. The results show that average daily gain in the E. coli challenged piglets (III and IV) was decreased (PE.coli<0.05). However, it tended to be higher in the NCG treated piglets (II and IV). Ileum secretory IgA, as well as IFN-γ, IL-2, IL-4 and IL-10 in ileal homogenates, were increased in E. coli challenged piglets (III and IV). Similarly, ileum SIgA and IL-10 levels, and CD4(+) percentage in NCG treated piglets (II and IV) were higher than no-NCG treated piglets (PNCG<0.05). However, the IL-2 level was only decreased in the piglets of E. coli challenge + NCG group (IV) compared with E. coli challenge group (III) (P<0.05). No change in the IL-2 level of the sham challenged piglets (III) was observed. In conclusion, dietary NCG supplementation has some beneficial effects on intestinal mucosal immunity in E. coli challenged piglets, which might be associated with stimulated lymphocyte proliferation and cytokine synthesis. Our findings have an important implication that NCG may be used to reduce diarrhea in neonatal piglets.

Identification of alpha-1 acid glycoprotein (AGP) as a potential marker of impaired growth in the newborn piglet.

Two studies were conducted to investigate the relationship between circulating levels of haptoglobin and α-1 acid glycoprotein (AGP) and growth in neonatal pigs. Circulating serum AGP, but not haptoglobin, was higher (P<0.001) in newborn runts than average-sized littermates. At 1 and 3 weeks, AGP and haptoglobin were similar among control and runt piglets. To determine the possible association between AGP and growth rate, blood was collected between the first and second day after birth in piglets from 10 average litters. Birthweight was positively correlated with growth rate through 21 days (linear regression correlation coefficient (CC), 0.43 (P<0.006); 0.299 (P<0.003) in males and females, respectively). Plasma AGP at birth was negatively correlated with growth (CC, -0.429 (P<0.006); -0.351 (P<0.01) in males and females, respectively). When AGP was calculated on a per kg birthweight basis, the CC with growth improved by 25 and 34% in males and females, respectively, compared with birthweight alone. Haptoglobin in blood was not correlated with growth. These data suggest that AGP at birth is reflective of growth conditions in utero or fetal maturation and may serve as an early predictive biomarker for pre-weaning growth rate.

Actinobacillus pleuropneumoniae is impaired by the garlic volatile allyl methyl sulfide (AMS) in vitro and in-feed garlic alleviates pleuropneumonia in a pig model.

Decomposition products of ingested garlic are to a certain extent excreted via the lungs. If the supposed health-supporting capacities associated with garlic extend to these exhaled sulfurous compounds, they could have an effect on the course of pneumonia. In this study, the garlic-derived volatile allyl methyl sulfide (AMS) as a lead compound of volatile garlic metabolites was shown to exhibit an antibacterial effect against the pig pathogen Actinobacillus pleuropneumoniae serotype 9. AMS caused a delay in the appearance of the optical density-monitored growth of A. pleuropneumoniae in medium when compared to unaffected growth curves, yet without lowering the stationary phase yield at the concentration range tested. At 1.1mM, AMS impaired the in vitro growth rate of A. pleuropneumoniae serotype 9 by 8% compared to unimpeded growth. In an animal trial, a garlic-fed group of 15 pigs that received a diet with 5% garlic feed component and a control group of 15 pigs that received a diet without garlic were infected with A. pleuropneumoniae serotype 2 via an aerosol and subsequently followed for 4 days. At the day of the challenge, blood AMS in the garlic-fed group amounted to 0.32 ± 0.13 µM. A beneficial, alleviating effect of garlic on the course and severity of an A. pleuropneumoniae infection in pigs was indicated by the reduced occurrence of characteristic pleuropneumonia lesions (27% of the lungs affected in the garlic-fed group vs. 47% in the control group) and a near to significant (p=0.06) lower relative lung weight post mortem in the garlic-fed group.

Effects of a "step-up" ractopamine feeding program, sex, and social rank on growth performance, hoof lesions, and Enterobacteriaceae shedding in finishing pigs.

Increasing concern for animal well-being and food safety has stimulated the investigation of feed additives such as ractopamine (RAC), a beta-agonist widely used to improve production performance of finishing pigs. The objective of this study was to determine effects of RAC feeding, delivered as a "step-up" program (5 mg/kg for 2 wk followed by 10 mg/kg for 2 wk), on growth performance, Enterobacteriaceae shedding, including Salmonella, and hoof lesions, also taking into account sex and social rank of pigs. A total of 64 barrows and gilts (balanced by treatment and sex) were assigned to pens of 4 (by sex) as either control (CTL) or RAC treatment. Social ranks (dominant, intermediate, and subordinate) of pigs in each pen were determined by behavioral observation during 48 h post-mixing. Fecal samples were collected once per week for 5 wk. At slaughter, the 32 dominant and subordinate barrows and gilts (16/sex) were examined for hoof lesions, and luminal contents from ileum, cecum, and rectum were collected. Pigs fed RAC had increased growth performance (P < 0.05) with social rank of animals affecting overall ADG (P < 0.05). Gilts gained more backfat than barrows when comparing to baseline values at both 10th and last ribs (P < 0.05), whereas loin eye area increased at a similar rate for both barrows and gilts (P > 0.10). No significant effect of RAC feeding was found on backfat or loin eye area (P > 0.10). At slaughter, RAC-fed pigs had greater BW (P < 0.05). Despite the positive effects of RAC feeding on growth performance, pigs fed the compound had a greater frequency of front and rear hoof lesions as did barrows and dominant individuals (P < 0.05). Detectable concentrations of Salmonella shedding were not identified at any time during the experiment. Enterobacteriaceae shedding concentrations from RAC-fed pigs peaked at the first week of feeding and progressively decreased until slaughter. At slaughter, rectal and cecal Enterobacteriaceae concentrations were less in RAC-fed pigs than in CTL pigs (P < 0.05). Social rank tended to affect gut Enterobacteriaceae populations of barrows more than in gilts (P < 0.10). The effects of RAC feeding on hoof soundness and Enterobacteriaceae populations in the gastrointestinal tract of finishing pigs warrant further investigation. It is also proposed that the integration of the social rank status of the individual into future studies should be considered, because it may affect treatment responses.

Dietary tryptophan helps to preserve tryptophan homeostasis in pigs suffering from lung inflammation.

In pigs, inflammation modifies Trp metabolism and consequently could impact on Trp requirement for growth. In this study, the effects of lung inflammation, induced by the intravenous injection of complete Freund's adjuvant, and dietary Trp content on Trp metabolism and availability were investigated. Two dietary Trp contents, one corresponding to a low-Trp diet (1.5 g of Trp/kg of diet, Basal diet) and the second to an adequate-Trp diet (2 g of Trp/kg of diet, TRP diet), were used. Ten blocks of 4 littermate piglets were selected at 40 d of age. Within each block, piglets were randomly assigned to 1 of the 4 experimental treatments: (1) healthy control and Basal diet, (2) inflammation and Basal diet, (3) inflammation and Basal diet + antioxidant, and (4) inflammation and TRP diet. Inflammation induced an increase in indoleam-ine 2,3 dioxygenase (IDO) activity, an enzyme involved in Trp catabolism, in lung, lymph nodes, heart, and spleen (P < 0.01). Contrary to piglets fed the TRP diet, pigs suffering from inflammation did not maintain their plasma Trp concentrations when they were fed the Basal diet. Furthermore, pigs fed the TRP diet had decreased plasma haptoglobin concentrations, IDO activity, and lung weight than those fed the Basal diet, indicating that the inflammatory response was moderated with the greater Trp supply. Antioxidant addition in the Basal diet decreased the effects of inflammation on plasma Trp concentrations and IDO activity. These results indicated that inflammation increases Trp catabolism and thus may decrease Trp availability for growth.

The effect of inulin on new and on patent infections of Trichuris suis in growing pigs.

The objective of this experiment was to investigate the potential influence of inulin on the establishment of new and patent infections of Trichuris suis in growing pigs. Two experimental diets were formulated based on barley flour with either added insoluble fibre from oat husk (Diet 1) or a pure inulin (16%) supplementation (Diet 2). Twenty-eight 10-week-old pigs were divided randomly into 4 groups (Groups 1-4) each of 7 pigs. After 3 weeks adaptation to the experimental diets all pigs were infected with a single dose of 2000 infective T. suis eggs. Group 1 was fed Diet 1 until 7 weeks post-infection (p.i.) and Group 3 until 9 weeks p.i., Group 2 was fed Diet 2 until 7 weeks p.i., Group 4 was fed Diet 1 until week 7 p.i. and was switched-over from Diet 1 to Diet 2 until week 9 p.i. Seven weeks p.i. pigs in Groups 1 and 2 were slaughtered, and pigs in Groups 3 and 4 were slaughtered at 9 weeks p.i. Trichuris suis worm burdens were determined for all pigs. Inulin-fed pigs (Group 2) exhibited an 87% reduction in EPG, compared to the pigs on standard diet (Group 1) (P < 0.0001). The number of worms recovered at week 7 p.i. from pigs on the inulin diet (Group 2) was significantly reduced by 71%, compared to the pigs on standard diet (Group 1) (P < 0.01). At week 9, worm recovery in pigs on the inulin diet switch protocol (Group 4) was reduced by 47% compared to the control pigs in Group 3 (P < 0.01). Further, the inulin-fed pigs exhibited a significant reduction in female worm fecundity and worm large intestine location was more distal compared to those from pigs on standard diet. These results demonstrate that inclusion of the highly degradable fructose polymer inulin in the diet leads to significant reductions in T. suis establishment, egg excretion, and female worm fecundity and can be used as a treatment for patent infections.

The effect of fermentable carbohydrates on experimental swine dysentery and whip worm infections in pigs.

An experiment was conducted to study the effect of diets with contrasting fermentability in the large intestine on experimental infections with Brachyspira hyodysenteriae, the causative agent of swine dysentery, and the whip worm, Trichuris suis, in pigs. Two diets with organically grown ingredients were composed. Both diets were based on triticale and barley and supplemented with either rape seed cake (Diet 1) or dried chicory root and sweet lupins (Diet 2). The study had a three-factorial design, with eight groups of pigs receiving Diet 1 or Diet 2, +/-B. hyodysenteriae, and +/-T. suis. Pigs fed Diet 2 and challenged with B. hyodysenteriae did not develop swine dysentery and B. hyodysenteriae was not demonstrated in any of the pigs during the study. In contrast, 94% of the B. hyodysenteriae challenged pigs fed Diet 1 showed clinical symptoms of swine dysentery and all the pigs were shedding B. hyodysenteriae in faeces at some points in time during the experiment. The number of T. suis was lower in pigs fed Diet 2 compared to pigs fed Diet 1, but the differences were not significant. Pigs on Diet 1 and challenged with both pathogens showed clinical symptoms of SD for a longer period than pigs inoculated with B. hyodysenteriae only. The study showed that diets supplemented with highly fermentable carbohydrates from dried chicory roots and sweet lupins can protect pigs against developing swine dysentery, but do not have any significant influence on T. suis.

Effect of processed and fermented soyabeans on net absorption in enterotoxigenic Escherichia coli-infected piglet small intestine.

Infectious diarrhoea is a major problem in both children and piglets. Infection of enterotoxigenic Escherichia coli (ETEC) results in fluid secretion and electrolyte losses in the small intestine. In the present study the effect of processed and fermented soyabean products on net absorption during ETEC infection was investigated. Soyabean was processed into an autoclaved, a cooked and a mould-fermented (tempeh) product. The soyabean products were pre-digested and the effect of the products on net absorption in the small intestine of piglets was studied. Pairs of small-intestinal segments, one non-infected and the other ETEC-infected, were perfused simultaneously with the different products during 8 h. Net absorption of fluid, DM, Na, chloride, K and total solutes was determined. Net fluid absorption was highest for cooked soyabean followed by autoclaved soyabean and tempeh as a result of the osmolality of these products. In ETEC-infected segments, cooked soyabean and tempeh showed minor fluid losses (27 (SE 23) and 43 (SE 20) microl/cm(2), respectively) compared with the saline control (260 (SE 23) microl/cm(2)). Tempeh resulted in a high uptake of solutes. Processed soyabean products, particularly cooked soyabean and tempeh, are beneficial in maintaining fluid balance during ETEC infection. Additionally, tempeh showed high DM and total solute absorption. Therefore, particularly, tempeh may be beneficial in the case of post-weaning diarrhoea in piglets and possibly in children as well.

The influence of dietary carbohydrates on experimental infection with Trichuris suis in pigs.

Two experiments (Exps 1 and 2) were carried out to study the effect of dietary carbohydrates on the establishment of Trichuris suis in pigs. Two experimental diets based on barley flour were used; Diet 1 was supplemented with non-fermentable carbohydrates from oat hull meal, while Diet 2 was supplemented with fermentable carbohydrates from sugar beet fibre and inulin. In Exp. 1, thirty-two pigs were allocated randomly into 4 groups. Two groups were fed Diet 1 and 2 groups were fed Diet 2. Pigs from one of each diet group were inoculated with 2000 infective T. suis eggs each and the other two groups were uninfected controls. All pigs were slaughtered 8 weeks post-inoculation (p.i.). In Exp. 2, twenty-four pigs were allocated randomly into 2 groups and fed Diet 1 or Diet 2, respectively. All the pigs were inoculated with 2000 infective T. suis eggs. Six pigs from each group were slaughtered 8 weeks p.i. and the remaining 6 pigs from each group were slaughtered 12 weeks p.i. Infections were followed by faecal egg counts and worm burdens were assessed at necropsy. Pigs fed Diet 2 had lower egg counts in both experiments; in Exp. 2 the difference was significant (P<0.05). No differences were found in worm burdens 8 weeks p.i. in both experiments, however, worms from pigs on Diet 2 were significantly shorter (P<0.0001). Pigs fed Diet 2 and slaughtered 12 weeks p.i. had significantly lower worm counts (P<0.01) compared to pigs fed Diet 1. The results indicate that fermentable carbohydrates do not affect the establishment of T. suis in naïve pigs, but result in earlier expulsion and reduced growth of the established worms. Thus, diets with highly fermentable carbohydrates may be used in the control of T. suis.

Effect of medium- and long-chain triglyceride supplementation on small newborn-pig survival.

The pre-weaning survival of 508 piglets was studied with a categorical survival analysis, evaluating the effect of medium-long-chain triglyceride (MCT-LCT) supplementation on small newborn pigs, and determining additional risk factors. Half of the 98 piglets born with birth weight (BW)<1250 g received 1.95 g of MCT-LCT each 24 h during the first 3 days of life, and their death hazard was reduced 1.9-fold in relation with small unsupplemented siblings. The death hazard ratio (HR) of supplemented animals compared to 410 heavier littermates was not different. However, the HR for newborn pigs that were small in relation with their siblings was 2.8, and the HR for litters with >12 piglets born alive was 4.5. There was variation across months, and also piglets from primiparous sows had increased hazard of death (HR=4.0).

The effect of fasting on Ascaris suum and Oesophagostomum spp. in growing pigs.

Experiments were conducted to study the possible influence of fasting on Ascaris suum and Oesophagostomum spp. In growing pigs. Forty young crossbred pigs naturally infected with A. suum and Oesophagostomum spp. were used. In one experiment 10 pigs were fasted and offered water ad libitum for 6 days, in another experiment for 10 days. Subsequently, these pigs, together with 10 non-fasted control pigs per experiment were slaughtered, and worm numbers, worm location, sex, developmental stage and female worm fecundity were determined. Pigs fasted for 10 but not for 6 days had decreased numbers of A. suum and Oesophagostomum spp. at slaughter vs controls, and worms were found in more distal locations in the gastrointestinal tract. Fasting for both 6 and 10 days significantly lowered the fecundity of both worm species.