Weaner Pigs Research Articles

Pre-weaning social behaviours and peripheral serotonin levels are associated with behavioural and physiological responses to weaning and social mixing in pigs

In pig production systems, weaning is a major challenge that is usually paired with social mixing and may greatly affect health and welfare of piglets. Research efforts have been devoted to characterising early predictors of weaning adaptation, but have focused mainly on aggressive and harmful behaviours, whereas socio-positive behaviours have been poorly studied. Furthermore, serotonin (5-HT), a neurotransmitter regulating social behaviours, may also be a pertinent predictor of piglets’ adaptation to challenging situations. This study aimed to assess whether social behaviours and blood 5-HT concentration before weaning were associated with behavioural and physiological responses of piglets to weaning. Social interactions (social exploration, aggression, play-fight, locomotor play) of 72 focal piglets from 12 litters were scored continuously for 8 h at 42 days of age. At weaning (d48), focal piglets were allocated to four pens of 33 piglets from six litters. During the two days following weaning (d49–50), social interactions were scored continuously for 6 h per day, and behavioural activities were scored with 6-min instantaneous scan sampling. Blood was sampled one week before (d41) and 24 h after (d49) weaning to measure 5-HT concentrations and health-related variables. Exploration of pen mates represented 55% and 79% of all scored social interactions before and after weaning, respectively, and play was not observed after weaning. Using a multivariate analysis paired with clustering analysis on post-weaning behavioural and physiological responses, we identified three clusters of piglets with distinct profiles of adaption to weaning: unhealthy inactive animals, healthy inactive aggressors and healthy active affiliative animals. Compared to other clusters, unhealthy inactive animals at weaning were characterised by lower levels of social exploration and aggression before weaning (p < 0.05 for both). Furthermore, piglets that explored their pen mates more before weaning were more active (p = 0.03) after weaning, while piglets that were involved in greater number of locomotor play episodes (p = 0.009) or that were less aggressive (p = 0.04) before weaning walked more after weaning. Piglets with higher blood 5-HT concentrations before weaning were less aggressive (p = 0.01) and had greater growth (p = 0.009) after weaning. Pre-weaning aggression was also positively associated with post-weaning lymphocyte count (p = 0.04), and pre-weaning locomotor play with post-weaning hydroperoxide concentration (p = 0.05), a marker of oxidative stress. Our findings suggest that pre-weaning social behaviours and blood 5-HT concentration may be relevant predictors of piglets’ adaptive responses to social mixing at weaning and deserve more research attention.

Correction to: Replacing dietary antibiotics with 0.20% L-glutamine and synbiotics following weaning and transport in pigs

Correction to: Replacing dietary antibiotics with 0.20% L-glutamine and synbiotics following weaning and transport in pigs

Dietary glycine supplementation enhances postweaning growth and meat quality of pigs with intrauterine growth restriction.

Pigs with intrauterine growth restriction (IUGR) have suboptimum growth performance and impaired synthesis of glycine (the most abundant amino acid in the body). Conventional corn- and soybean meal-based diets for postweaning pigs contain relatively low amounts of glycine and may not provide sufficient glycine to meet requirements for IUGR pigs. This hypothesis was tested using 52 IUGR pigs and 52 litter mates with normal birth weights (NBW). At weaning (21 d of age), IUGR or NBW pigs were assigned randomly to one of two nutritional groups: supplementation of a corn-soybean meal-based diet with either 1% glycine plus 0.19% cornstarch or 1.19% L-alanine (isonitrogenous control). Feed consumption and body weight (BW) of pigs were recorded daily and every 2 or 4 wks, respectively. All pigs had free access to their respective diets and clean drinking water. Within 1 wk after the feeding trial ended at 188 d of age, blood and other tissue samples were obtained from pigs to determine concentrations of amino acids and meat quality. Neither IUGR nor glycine supplementation affected (P > 0.05) feed intakes of pigs per kg BW. The final BW, gain:feed ratio, carcass dressing percentages, and four-lean-cuts percentages of IUGR pigs were 13.4 kg, 4.4%, 2%, and 15% lower (P < 0.05) for IUGR pigs than NBW pigs, respectively. Compared with pigs in the alanine group, dietary glycine supplementation increased (P < 0.05) final BW, gain:feed ratio, and meat a* value (a redness score) by 3.8 kg, 11%, and 10%, respectively, while reducing (P < 0.05) backfat thickness by 18%. IUGR pigs had lower (P < 0.05) concentrations of glycine in plasma (-45%), liver (-25%), jejunum (-19%), longissimus dorsi muscle (-23%), gastrocnemius muscle (-26%), kidney (-15%), and pancreas (-6%), as compared to NBW pigs. In addition, dietary glycine supplementation increased (P < 0.05) concentrations of glycine in plasma and all analyzed tissues. Thus, supplementing 1% of glycine to corn-soybean meal-based diets improves the growth performance, feed efficiency, and meat quality of IUGR pigs.

Leucine (and lysine) increased plasma levels of the satiety hormone cholecystokinin (CCK), and phenylalanine of the incretin glucagon-like peptide 1 (GLP-1) after oral gavages in pigs.

Excess dietary amino acids (AA) has been associated with reduced feed intake, increased satiation, and extended satiety in pigs. Recent ex vivo studies suggested that satiety peptide cholecystokinin (CCK) and insulinotropic glucagon-like peptide 1 (GLP-1), mediated the anorexigenic or insulinotropic effects of Lys, Glu, Phe, Ile, and Leu. However, the ex vivo model limitations require validation in vivo. The aim of the present study was to assess the effect of orally administered AA in vivo in pigs. It was hypothesized that oral Lys, Ile, and Leu have an anorexigenic effect via CCK, while Glu and Phe have an insulinotropic effect increasing circulating levels of GLP-1. Eight entire male pigs (Landrace × Large White) of 18.23 ± 1.06 kg of body weight were administered an oral gavage of water (control) or a 3 mmol/kg of Glu, Ile, Leu, Lys, Phe, or glucose (positive control for GLP-1 release) following an overnight fasting during 5 consecutive days using an incomplete latin square design. Blood samples were collected from the jugular vein before (-5 min, baseline value) and after the gavage (5, 15, 30, 60 and 90 min) to assess CCK and GLP-1 plasma levels. Pigs administered the oral gavage of Leu (P < 0.05), or Lys (P < 0.1) had increased levels of plasma CCK from 0 to 90 min post-gavage when compared to the control. A strong association (P < 0.001) was observed between GLP-1 plasma levels with Phe intake. The impact was significant starting 30 min post-gavage and was sustained until the end of the experiment (90 min post-gavage). Glucose administration increased GLP-1 early after the intake at the 5 min mark (P < 0.1). A positive correlation (P < 0.05, r = 0.89) driven by the impact of Phe at the 60 to 90 min post-gavage was identified between CCK and GLP-1 indicating feedback mechanisms between proximal and distal small intestine. In conclusion, oral gavages of Leu and Lys increased anorexigenic hormone CCK plasma levels in pigs. Phe caused a significant long-lasting increase in incretin GLP-1 plasma levels. Blood CCK and GLP-1 concentrations in Phe gavaged pigs were positively correlated indicating a potential feedback mechanism between proximal (CCK) and distal (GLP-1) small intestine. The present results are compatible with the known anorexigenic effects of excess dietary Leu and Lys, and the insulinotropic effect of Phe in pigs. These results demonstrate the relevance of accurate feed formulation practices particularly in post weaning pigs.

Influence of dietary manipulation on coping with stress in pig production

Abstract Pigs for commercial production are often housed intensively because of its benefits, such as proper management of the animals, record‑keeping, feed and water provision and management. However, intensive systems of production may also produce stress in animals, arising from operations such as weaning, feed reduction or manipulation, and vaccination. In Africa, pig farmers feed cassava peels to pigs to reduce the cost of production despite its low protein content and anti‑nutritional factor (hydrocyanide). However, little is known about the effect of this feed change in terms of stress on weaners. In this study, we replaced maize with cassava peels and supplemented the diets with a fixed amount of tryptophan (Trp) to investigate its effect on performance, haematology, behavioural response of pigs to weaning, and their response to metabolic stress. Crossbred weaner pigs were used and randomly assigned to three treatments in a completely randomised design. Each treatment had three replicates and each replicate had three animals. The feeding trial lasted for four weeks. Dietary manipulations did not influence the growth performance characteristics and behavioural response of the animals. Packed cell volume, haemoglobin, red blood cell counts, and neutrophils were significantly (p &lt; 0.05) higher for 20 % cassava peel as a replacement for maize but lower for a 40 % cassava peel‑based diet when compared with the control group. Feeding cassava peels as a replacement for maize in weaner pigs may be carefully considered, although further studies in this direction are recommended.

Water use patterns within each day: Variation between batches of growing pigs in commercial production systems

Objective: To measure, describe, and compare the water use patterns within each day for multiple cohorts of weaner, grower, and finisher pigs in farm buildings. Materials and methods: Prospective, observational cohort studies of the water use patterns within each day were conducted in 5 pig buildings using either a turbine or ultrasonic water flow meter attached to the main water pipe entering each building. Water use data were collected from multiple batches of pigs (second-stage weaners over eleven 48-day periods and grower-finishers over 4 periods of 21-43 days). Semi-parametric models of pig water use patterns within each day were estimated using the brms software package in R. To estimate the interacting effects of time and pig body weight on water use by pigs, we used tensor product smooths for time and pig body weight. Results: The water use pattern within each day varied between the cohorts, and the pattern of many cohorts changed as the pigs gained weight. Some patterns were unimodal and others were bimodal, with the main peak in water use occurring early afternoon to late afternoon. Implications: Water use patterns of pigs within each day varied between and within cohorts. The water use pattern of one cohort cannot be used reliably to predict that of other cohorts, even if they are reared in the same building. Water use pattern data may be valuable for optimizing in-water antimicrobial dosing regimens.

Estimating potential farm economic benefits of advanced microbiological diagnostics in veterinary medicine

Context Intensive livestock production is challenged by frequent occurrence of contagious livestock diseases. Advanced diagnostic tools, such as quantitative polymerase chain reaction (qPCR), have been found to improve the precision and speed of veterinary diagnostics. Aims This study develops and applies an analytical quantitative framework to investigate the potential farm economic benefits of introducing an advanced and rapid diagnostic tool that allows veterinarians accurately and fast to detect the load and composition of pathogens in production animals, compared with a scenario where decision-making is based on aggregate prevalence data. Methods A probabilistic budget simulation model for livestock production was developed, on the basis of farm-accounts data, epidemiological prevalence, mortality and morbidity data from official statistics, veterinary practice and literature findings, as well as experimental data regarding sensitivity and specificity of the specific diagnostic tool. Key results The framework was used to assess the expected economic gains of qPCR diagnostics for calf pneumonia and weaner pig diarrhoea. In both cases, positive economic gains were found, namely, 7.8% and 3.1% of gross margin in Danish calf production and weaner production respectively. Conclusions and Implications Use of rapid advanced diagnostic tools to diagnose calf pneumonia or weaner pig diarrhoea can lead to economic gains for farmers and improve the efficiency in use of resources in livestock production.

Experimental Infection of Streptococcus suis Isolate in Pig in Bali – Indonesia Produced Mild Clinical Signs but Severe Multiorgan Lesions

There has been uncertainty about Streptococcus suis (S. suis) causing disease in pig. Different inoculation routes might lead to different pathologic courses. Here, we provide data on experimental infection of weaning pigs with S. suis isolated from pigs with severe infections through intranasal (IN) and intravenous (IV) inoculation. Nine weaning landrace piglets were used as experimental animals. Three were inoculated with S. suis intranasally and three intravenously, each with 1x109CFU S. suis, while the other three were left uninoculated as control animals. Prior to inoculation, the animals were anesthetized using ketamine hydrochloride (10mg/BW) delivered intramuscularly. All control animals remained healthy throughout the study. Fever was observed in all IN and IV animals from 3 to 9 days post infection (dpi). Appetite loss was observed at 3 to 9dpi in the IN group and at 3 to 7dpi in the IV group. Diarrhea occurred in one animal in each group from 3-5dpi. Lameness was observed for one animal in the IN group. Body weights (bwt) on Day 14 of the IN, IV, and control group piglets were 11.93±0.83, 9.80±1.83, and 14.70±0.53kg, respectively. After 14 days, only four animals, three from the IN group and one from the IV group, showed pathological lesions of pneumonia and hemorrhage in the myocardium. Necropsied animals from both inoculation route groups showed inflammation in various organs. Using polymerase chain reaction, we identified S. suis from the culture of heart samples taken from animals with hemorrhage in the myocardium. We concluded that although producing a mild clinical course, S. suis isolated from severely diseased pigs causes multiorgan histological lesion development and slower weight gain. Appropriate vaccines against S. suis should reduce its financial and zoonotic impact.

Pathogen exposure influences immune parameters around weaning in pigs reared in commercial farms.

Multiple antigenic stimulations are crucial to immune system training during earlypost-natal life. These stimulations can be either due to commensals, which accounts for the acquisition and maintenance of tolerance, or to pathogens, which triggers immunity. In pig, only few works previously explored the influence of natural exposition to pathogens upon immune competence. We propose herein the results of a multicentric, field study, conducted on 265 piglets exposed to contrasted pathogen levels in their living environment. Piglets were housed in 15 different commercial farms, sorted in two groups, low (HSLOW)- and high (HSHIGH)-health status farms, depending on their recurrent exposition to five common swine pathogens. Using animal-based measures, we compared the immune competence and growth performances of HSLOW and HSHIGH pigs around weaning. As expected, we observed a rise in the number of circulating leucocytes with age, which affected different cell populations. Monocyte, antigen-experienced and cytotoxic lymphocyte subpopulation counts were higher in piglets reared in HSLOW farms as compared to their HSHIGH homologs. Also, the age-dependent evolution in γδ T cell and neutrophil counts was significantly affected by the health status. With age, circulating IFNα level decreased and IgM level increased while being greater in HSLOW piglets at any time. After weaning, LPS-stimulated blood cells derived from HSLOW piglets were more prone to secrete IL-8 than those derived from HSHIGH pigs did. Monocytes and granulocytes issued from HSLOW pigs also exhibited comparable phagocytosis capacity. Altogether our data emphasize the more robust immunophenotype of HSLOW piglets. Finally, piglets raised under higher pathogen pressure grew less than HSHIGH piglets did and exhibited a different metabolic profile. The higher cost of the immune responses associated with the low farm health status may account for lower HSLOW piglet performances. Altogether, our data, obtained in field conditions, provide evidence that early exposure to pathogens shapes the immune competence of piglets. They also document the negative impact of an overstimulation of the immune system on piglets' growth.

Full-fatted Hermetia illucens larva as a protein alternative: effects on weaning pig growth performance, gut health, and antioxidant status under poor sanitary conditions

ABSTRACT We investigated the effectiveness of full-fatted black soldier fly larvae (BSF) supplementation on growth performance, gut health, and antioxidant capacity of weaned pigs under poor sanitation. Eighty 28-d-old piglets were divided into four groups (five replicates of four pigs each): control group comprising pigs under hygienic conditions without BSF addition (PC); control group comprising pigs under poor sanitary conditions without BSF addition (NC); and BSF6 and BSF12 groups comprising pigs supplemented 6% and 12% BSF, respectively. Pigs were fed the diets in two feeding programs: Phase I (1–14 d) and II (15–28 d) containing 3,300 and 3,265 kcal/kg of metabolisable energy and 22.5% and 21.5% of crude protein, respectively. Compared to the NC, the BSF6 and BSF12 increased body weight and average daily feed intake in Phase II (P < 0.05). The BSF exhibited greater nutrient digestibility, immunoglobulin A and glutathione peroxidase levels, cecum weights, duodenal villus height, duodenal villus-to-crypt depth ratio, and caecal Lactobacillus spp. (P < 0.05). Furthermore, the BSF6 and BSF12 showed significantly decreased diarrheal rate, tumour necrosis factor-alpha, small intestine weight, caecal pH, and duodenal crypt depth unlike the NC (P < 0.05). The BSF12 had lower malondialdehyde concentration and Escherichia coli than the NC (P < 0.05). In conclusion, the addition of 12% BSF improved growth performance and nutrient utilisation, thereby reducing gut inflammation and modulating antioxidant capacity in post-weaning piglets.

Molecular characterization of gut microbiome in weaning pigs supplemented with multi-strain probiotics using metagenomic, culturomic, and metabolomic approaches

BackgroundProbiotics have been reported to exhibit positive effects on host health, including improved intestinal barrier function, preventing pathogenic infection, and promoting nutrient digestion efficiency. These internal changes are reflected to the fecal microbiota composition and, bacterial metabolites production. In accordance, the application of probiotics has been broadened to industrial animals, including swine, which makes people to pursue better knowledge of the correlation between changes in the fecal microbiota and metabolites. Therefore, this study evaluated the effect of multi-strain probiotics (MSP) supplementation to piglets utilizing multiomics analytical approaches including metagenomics, culturomics, and metabolomics.ResultsSix-week-old piglets were supplemented with MSP composed of Lactobacillus isolated from the feces of healthy piglets. To examine the effect of MSP supplement, piglets of the same age were selected and divided into two groups; one with MSP supplement (MSP group) and the other one without MSP supplement (Control group). MSP feeding altered the composition of the fecal microbiota, as demonstrated by metagenomics analysis. The abundance of commensal Lactobacillus was increased by 2.39%, while Clostridium was decreased, which revealed the similar pattern to the culturomic approach. Next, we investigated the microbial metabolite profiles, specifically SCFAs using HPLC–MS/MS and others using GC–MS, respectively. MSP supplement elevated the abundance of amino acids, including valine, isoleucine and proline as well as the concentration of acetic acid. According to the correlation analyses, these alterations were found out to be crucial in energy synthesizing metabolism, such as branched-chain amino acid (BCAA) metabolism and coenzyme A biosynthesis. Furthermore, we isolated commensal Lactobacillus strains enriched by MSP supplement, and analyzed the metabolites and evaluated the functional improvement, related to tight junction from intestinal porcine enterocyte cell line (IPEC-J2).ConclusionsIn conclusion, MSP administration to piglets altered their fecal microbiota, by enriching commensal Lactobacillus strains. This change contributed amino acid, acetic acid, and BCAA concentrations to be increased, and energy metabolism pathway was also increased at in vivo and in vitro. These changes produced by MSP supplement suggests the correlation between the various physiological energy metabolism functions induced by health-promoting Lactobacillus and the growth performance of piglets.

Diets Fermented with Bacteria and Enzymes in China Improve Growth Performance and Health of Weaned Piglets

Microbial fermentation has been widely used to preserve or improve the nutritional properties of food. Liquid feeding can increase feed intake and reduce the morbidity of piglets. The objective of this study was to evaluate the effects of a diet fermented with bacteria and enzymes and liquid feeding on growth performance, nutrient digestibility, digestive enzyme activity, microflora, and expressions of intestinal development-related genes in weaning pigs. A total of 198 piglets (Duroc × Landrace × Yorkshire) with body weights of 8.70 ± 0.45 kg were assigned to three groups with six replicates per treatment, and 11 weaned piglets per replicate according to the initial body weight and sex. The three dietary treatments (all nonpelleted diets) were a standard dry feed as the control (CON), a control diet supplemented with antibiotics (AB), and a liquid feeding with a fermented diet (LFD). The liquid feeding diet, having the same composition and proportion of each ingredient as the control diet, was prepared by storing the dietary cereals (corn, soybeans, etc.) and water (1:0.5, wt/wt) in a closed tank at 26–30 °C with enzymes and bacteria, and then adding the remaining dietary ingredients immediately before feeding. The whole trial lasted 42 days. On days 11 to 14 and 39 to 42, fresh faecal samples were collected to evaluate the apparent total tract digestibility of nutrients. Performance, digestibility, serum physiochemical parameters, intestinal barrier function, microbiota, and microbial metabolites were measured. The experimental data were subjected to analysis of variance using the GLM procedure of SAS for a complete randomized block design, with a “pen” as the experimental unit. The results showed that the AB increased (p &lt; 0.05) average daily gain and reduced (p &lt; 0.05) feed conversion (F/G) over the course of 1–14 days compared to the control. The liquid feeding group significantly increased (p &lt; 0.05) average daily gain, average daily feed intake, and final body weight compared to the other two dietary groups. The digestibility of crude protein, ether extract, ash, gross energy, Ca, and P also improved in the liquid feeding group. Moreover, the liquid feeding group significantly decreased (p &lt; 0.05) serum urea nitrogen and D-lactate concentrations, as well as the activity of diamine oxidase, and increased (p &lt; 0.05) serum total protein and glucose concentrations on day 14. Furthermore, the liquid feeding group significantly increased (p &lt; 0.05) mRNA expressions of zonula occludens-2 (ZO-2) in the jejunum and zonula occludens-1 (ZO-1), ZO-2, occludin, and claudin-1 in the ileum. In addition, microbiota measurement suggested an increase in Lactobacillus content and a decrease in Escherichia coli with higher (p &lt; 0.05) concentrations of acetic acid, propionic acid, butyric acid, and total volatile fatty acids in the caecal and colonic digesta of piglets in the liquid feeding group. In conclusion, the diet in the liquid feeding group was able to increase palatability, improve nutrient digestibility, and modulate metabolism, which resulted in higher feed efficiency and better growth performance in the piglets.

Effects of β-glucan with vitamin E supplementation on the growth performance, blood profiles, immune response, fecal microbiota, fecal score, and nutrient digestibility in weaning pigs.

This study was conducted to evaluate effects of β-glucan with vitamin E supplementation on the growth performance, blood profiles, immune response, fecal microbiota, fecal score, and nutrient digestibility in weaning pigs. A total of 200 weaning pigs with an average body weight (BW) of 7.64±0.741 kg were allotted to five treatment groups and were divided based on sex and initial BW in four replicates with ten pigs per pen in a randomized complete block design. The experimental diets included a corn‒soybean meal-based basal diet with or without 0.1% or 0.2% β-glucan and 0.02% vitamin E. The pigs were fed the diets for 6 weeks. A total of 15 barrows were used to evaluate the nutrient digestibility by the total collection method. The BW and feed intake were measured at the end of each phase. Blood samples were collected at the end of each phase, and fecal samples were collected at the end of the experiment. The addition of β-glucan with vitamin E to weaning pig feed increased BW, average daily gain, and average daily feed intake. A significant decrease in yeast and mold and Proteobacteria and a tendency for Lactobacillus to increase compared to the control was shown when 0.1% β-glucan and 0.02% vitamin E were added. The fecal score in weaning pigs was lower in the treatments supplemented with 0.1% or 0.2% β-glucan and 0.02% vitamin E compared to the control. In addition, vitamin E was better supplied to weaning pigs by increasing the concentration of α-tocopherol in the blood of weaning pigs when 0.02% vitamin E was supplemented. However, there was no significant difference in either the immune response or nutrient digestibility. Inclusion of 0.1% β-Glucan with 0.02% vitamin E in a weaning pig's diet were beneficial to the growth performance of weaning pigs by improving intestinal microbiota and reducing the incidence of diarrhea.

Prevalences and excretion levels of Lawsonia intracellularis, Brachyspira pilosicoli and Escherichia coli F4 and F18 in fecal sock samples from Danish weaner and finisher pig batches and the association with diarrhea

BackgroundBacterial enteritis in growing pigs is a matter of concern in Danish pig production challenging herd health as well as production economy, and antimicrobial usage. The aim of this observational study using fecal sock samples was to determine the prevalence and excretion level of Lawsonia intracellularis (LI), Brachyspira pilosicoli (BP), Escherichia coli F4 (F4) and F18 (F18) and to investigate associations between prevalence or excretion levels of the bacteria and diarrhea. The study was performed in the late weaner and the early finisher period in herds with a history of diarrhea. Every weaner and finisher herd contributed with one sample each.ResultsIn total, 47 weaner and 59 finisher herds were sampled. The overall prevalence and excretion levels (median and range in log(10) copies/gram of feces) were for LI 84.0% (median 6.2; range 3.0–7.7), for BP 45.2% (median 5.6; range 3.0–6.6), for F18 20.8% (median 5.7; range 4.7–7.7), and for F4 4.7% (median 5.5; range 5.2–6.0). In both diarrheic and non-diarrheic samples, the most prevalent bacteria were either LI alone or LI and BP in combination. In general, no association was found between increasing total bacterial excretion levels and diarrhea, but prevalence (p = 0.04) and excretion (p < 0.01) level of F18 was found to be significantly higher in diarrheic samples. Further, a significant association was found between low LI excretion level and lack of diarrhea in weaner herds (p = 0.03). A significant positive correlation was found between excretion levels of LI and BP in diarrheic weaner herd samples (p = 0.02).ConclusionEnteric pathogens were prevalent in a wide range of bacterial excretion levels in both diarrheic and non-diarrheic samples. Especially LI and BP were frequently found and with a positive correlation between excretion levels. Even in the absence of diarrhea, high prevalence and excretion levels of LI and BP were detected, thus making the status of diarrhea an insufficient tool for assessing the severity of their infections.

Gut transcriptome reveals differential gene expression and enriched pathways linked to immune activation in response to weaning in pigs

Weaning represents one of the most critical periods in pig production associated with increase in disease risk, reduction in performance and economic loss. Physiological changes faced by piglets during the weaning period have been well characterised, however little is currently known about the underlying molecular pathways involved in these processes. As pig meat remains one of the most consumed sources of protein worldwide, understanding how these changes are mediated is critical to improve pig production and consequently sustainable food production globally. In this study, we evaluated the effect of weaning on transcriptomic changes in the colon of healthy piglets over time using an RNA-sequencing approach. The findings revealed a complex and coordinated response to weaning with the majority of genes found to be rapidly differentially expressed within 1day post weaning. Multiple genes and pathways affected by weaning in the colon were associated with immune regulation, cell signalling and bacterial defence. NOD-like receptors, Toll-like receptor and JAK-STAT signalling pathways were amongst the pathways significantly enriched. Immune activation was evidenced by the enrichment of pathways involved in interferon response, cytokines interactions, oxidoreductase activities and response to microbial invasion. Biosynthesis of amino acids, in particular arginine, was also amongst the most enriched KEGG pathways in weaned pigs, reinforcing the critical role of arginine in gut homeostasis under stress conditions. Overall, transcriptomic and physiological results suggest that pigs going through the weaning transition undergo a transient period of inflammatory state with a temporary breakdown of barrier functions in the gut. These findings could provide valuable tools to monitor host response post weaning, and may be of particular relevance for the investigation and development of intervention strategies aimed to reduce antibiotic use and improve pig health and performance.

Comparative study of the effects of high- versus low-dose zinc oxide in the diet with or without probiotic supplementation on weaning pigs' growth performance, nutrient utilization, fecal microbes, noxious gas discharges, and fecal score

This study was conducted to determine the effects of high- versus low-dose (3000 vs. 300) zinc oxide (ZnO) in combination with or without a probiotic complex (0.1%) on weaned piglet production efficiency, nutrient absorption, fecal bacterial counts, noxious gas emissions, and fecal score. A 42-day experiment included 180 crossbred weaned piglets [Duroc × (Yorkshire × Landrace); 28 days old; 6.61 ± 1.29 kg] and four dietary treatments. An HZ (high ZnO) diet increased body weight at week 6, average daily gain at week 3, week 6, and overall period, and gain-to-feed ratio (G:F) at week 3 compared with an LZ (low ZnO) diet. G:F tended to increase with the LZP (LZ with probiotic) diet compared with the HZP (HZ with probiotic) diet at week 1. Escherichia coli count decreased by HZ diet compared with the LZ diet. In addition, E. coli count decreased and Lactobacillus count increased with the HZP diet compared with the LZP diet. There was no effect of treatment on nutrient digestibility, noxious gas emission, and fecal score. No interactive effect was seen between ZnO and probiotic. Therefore, high-dose ZnO inclusion improved growth performance and probiotic addition improved fecal microbiota, but no synergistic effect was found from ZnO and probiotic complex interaction.

Dietary autolysed yeast modulates blood profiles, small intestinal morphology and caecal microbiota of weaning pigs

Yeast products are potential feed additives due to their beneficial effects on gut health. Thus, we verified the potential impacts of autolysed yeast (AY) on growth performance, blood profiles, gut morphology and microbiota in weaning pigs. In total, 72 castrated, commercial, crossbred, weaning pigs were divided into three groups, with each group consisting of eight replicates with three piglets each. The experimental diets were as follows: 1) control diet (0% AY); 2) diet with 1.0% AY; 3) diet with 3.0% AY. For the overall period, using 1.0% AY in the diet seemed to improve the feed conversion ratio (P = 0.09); whereas, other productive performance parameters were not significantly affected by the supplementations. Using 1.0% AY in the diet significantly decreased the blood urea nitrogen and neutrophil/lymphocyte ratio (N/L ratio) but increased the eosinophil count (P < 0.05). Adding AY to the diet did not influence caecal microbial diversity; using 1.0% AY in the diet decreased the abundances of the phylum Actinobacteria, the class Coriobacteriia and the family Coriobacteriaceae (P < 0.05). At the genus level, an AY inclusion level of 1.0% reduced the abundances of Collinsella, Clostridium and Catenibacterium and increased that of Marvinbryantia (P < 0.05). Furthermore, the abundance of butyrate-producing bacteria seemed to be increased by AY supplementation (P = 0.06). Pearson’s correlation coefficient (r) analysis revealed that AY intake was negatively associated with the abundance of pathogens of the genera Dorea (r = −0.84; P = 0.03) and Catenibacterium (r = −0.80; P = 0.04). This indicates that AY intake potentially reduces the population of some pathogenic bacteria at family level. Thus, using an appropriate AY inclusion level (1.0%) seemed to improve the feed use of postweaning pigs and clearly improved their small intestinal morphology, blood profiles and caecal microbiota.

Localized bioelectrical conduction block from radiofrequency gastric ablation persists after healing: safety and feasibility in a recovery model.

Gastric ablation has demonstrated potential to induce conduction blocks and correct abnormal electrical activity (i.e., ectopic slow-wave propagation) in acute, intraoperative in vivo studies. This study aimed to evaluate the safety and feasibility of gastric ablation to modulate slow-wave conduction after 2 wk of healing. Chronic in vivo experiments were performed in weaner pigs (n = 6). Animals were randomly divided into two groups: sham-ablation (n = 3, control group; no power delivery, room temperature, 5 s/point) and radiofrequency (RF) ablation (n = 3; temperature-control mode, 65°C, 5 s/point). In the initial surgery, high-resolution serosal electrical mapping (16 × 16 electrodes; 6 × 6 cm) was performed to define the baseline slow-wave activation profile. Ablation (sham/RF) was then performed in the mid-corpus, in a line around the circumferential axis of the stomach, followed by acute postablation mapping. All animals recovered from the procedure, with no sign of perforation or other complications. Two weeks later, intraoperative high-resolution mapping was repeated. High-resolution mapping showed that ablation successfully induced sustained conduction blocks in all cases in the RF-ablation group at both the acute and 2 wk time points, whereas all sham-controls had no conduction block. Histological and immunohistochemical evaluation showed that after 2 wk of healing, the lesions were in the inflammation and early proliferation phase, and interstitial cells of Cajal (ICC) were depleted and/or deformed within the ablation lesions. This safety and feasibility study demonstrates that gastric ablation can safely and effectively induce a sustained localized conduction block in the stomach without disrupting the surrounding slow-wave conduction capability.NEW & NOTEWORTHY Ablation has recently emerged as a tool for modulating gastric electrical activation and may hold interventional potential for disorders of gastric function. However, previous studies have been limited to the acute intraoperative setting. This study now presents the safety of gastric ablation after postsurgical recovery and healing. Localized electrical conduction blocks created by ablation remained after 2 wk of healing, and no perforation or other complications were observed over the postsurgical period.

Effect of iron-binding polypeptides and non-starch polysaccharides supplementation on growth performance and fecal scores of weaning pigs

Background: Weaning is the most stressful event in pig’s life, resulting in postweaning diarrhea and growth retardation. The supplementation of Advanced Digestion Enhancing Protein Plus Technology (ADEPPTTM), which contains iron-binding polypeptides and non-starch polysaccharides, to nursery diets may reduce the occurrence of diarrhea and enhance growth performance of weaning pigs. Objective: To evaluate the effect of ADEPPTTM supplementation on growth performance and fecal score in weaning pigs. Methods: At weaning, a total of 54 weaning pigs (initial body weight: 7.42 ± 0.52 kg) were assigned to 3 treatments in 3 replicates with 6 pigs per pen based on sex, breed, and body weight for a 28-d feeding trial. The pigs were fed corn-soybean meal-based diets containing 0.0, 0.5, and 1.0% of the ADEPPTTM product in 2 phases (d 0-14 and d 15-28 postweaning, respectively). In the first week (d 3-5 postweaning) of the trial, a pig was removed from each pen when diarrhea was observed, housed in a separate pen within treatment, and then treated for 3 days with a 100-ml solution of electrolytes and ADEPPTTM by drenching. Growth performance and fecal score (1=normal to 4=watery diarrhea) were measured. Results: In the feeding trial, there were no significant differences in body weight, average daily gain, and average daily feed intake throughout the overall period. However, a quadratic trend was observed in gain to feed ratio (p=0.09) for d 0-7 postweaning and overall period with increasing ADEPPTTM supplementation levels in which the greatest value was observed in the 0.5% ADEPPTTM level. The fecal score tended to decrease linearly with increasing ADEPPTTM levels during d 0-7 (p=0.11) and 0-14 (p=0.12) postweaning. There was no significant difference on fecal score of diarrheic pigs and average daily gain tended to increase linearly in d 21-28 postweaning (p=0.08) with increasing ADEPPTTM levels. Conclusion: These results indicate that 0.5% ADEPPTTM supplementation has a potential to enhance growth performance of weaning pigs and might be effective to prevent and control postweaning diarrhea.

Flagellin from Salmonella enteritidis Enhances the Immune Response of Fused F18 from Enterotoxigenic Escherichia coli.

F18 plays an important role in helping Enterotoxigenic Escherichia coli (ETEC) binds to specific receptors on small intestinal enterocytes, followed by secreting of toxins causing diarrhea in post-weaning piglets (post-weaning diarrhea, PWD). However, the F18 subunit vaccine is not sufficient to stimulate an immune response that can protect weaning pigs from F18-positive ETEC (F18+ETEC). Recently, a body of evidence shows that flagellin protein (FliC) helps to increase the immunity of fused proteins. Therefore, in this study, we combined FliC with F18 to enhance the immune response of F18. The f18 gene was obtained from F18+ETEC, then was fused with the fliC gene. The expression of recombinant FliC-F18 protein was induced by Isopropyl-beta-D-Thiogalactopyranoside (IPTG). The purified protein was tested in vivo in mouse models to evaluate the immunostimulation. Results showed that the fusion of FliC and F18 protein increased the production of anti-F18 antibodies. Besides, the anti-F18 antibody in the collected antiserum specifically identified F18+ETEC. This result provides proof-of-concept for the development of subunit vaccine to prevent PWD using F18 antigen.