Korean Red Ginseng and Rb1 restore altered social interaction, gene expressions in the medial prefrontal cortex, and gut metabolites under post-weaning social isolation in mice.

Background: Post-weaning social isolation (SI) reduces sociability, gene expressions including myelin genes in the medial prefrontal cortex (mPFC), and alters microbiome compositions in rodent models. Korean Red Ginseng (KRG) and its major ginsenoside Rb1 have been reported to affect myelin formation and gut metabolites. However, their effects under post-weaning SI have not been investigated. This study investigated the effects of KRG and Rb1 on sociability, gene expressions in the mPFC, and gut metabolites under post-weaning SI. Methods: C57BL/6J mice were administered with water or KRG (150, 400 mg/kg) or Rb1 (0.1 mg/kg) under SI or regular environment (RE) for 2 weeks during the post-weaning period (P21-P35). After this period, mice underwent a sociability test, and then brains and ceca were collected for qPCR/immunohistochemistry and non-targeted metabolomics, respectively. Results: SI reduced sociability compared to RE; however, KRG (400 mg/kg) and Rb1 significantly restored sociability under SI. In the mPFC, expressions of genes related to myelin, neurotransmitter, and oxidative stress were significantly reduced in mice under SI compared to RE conditions. Under SI, KRG and Rb1 recovered the altered expressions of several genes in the mPFC. In gut metabolomics, 313 metabolites were identified as significant among 3027 detected metabolites. Among the significantly changed metabolites in SI, some were recovered by KRG or Rb1, including metabolites related to stress axis, inflammation, and DNA damage. Conclusion: Altered sociability, gene expression levels in the mPFC, and gut metabolites induced by two weeks of post-weaning SI were at least partially recovered by KRG and Rb1.

Lactiplantibacillus argentoratensis AGMB00912 protects weaning mice from ETEC infection and enhances gut health.

Maintaining a healthy intestinal environment, optimal epithelial barrier integrity, and balanced gut microbiota composition are essential for the growth performance of weaning pigs. We identified Lactiplantibacillus argentoratensis AGMB00912 (LA) in healthy porcine feces as having antimicrobial activity against pathogens and enhanced short-chain fatty acid (SCFA) production. Herein, we assess the protective role of LA using a weaning mouse model with enterotoxigenic Escherichia coli (ETEC) infection. LA treatment improves feed intake and weight gain and alleviates colon shortening. Furthermore, LA inhibits intestinal damage, increases the small intestine villus height compared with the ETEC group, and enhances SCFA production. Using the Kyoto Encyclopedia of Genes and Genomes and other bioinformatic tools, including InterProScan and COGNIZER, we validated the presence of SCFA-producing pathways of LA and Lactiplantibacillus after whole genome sequencing. LA mitigates ETEC-induced shifts in the gut microbiota, decreasing the proportion of Escherichia and Enterococcus and increasing SCFA-producing bacteria, including Kineothrix, Lachnoclostridium, Roseuburia, Lacrimispora, Jutongia, and Blautia. Metabolic functional prediction analysis revealed enhanced functions linked to carbohydrate, amino acid, and vitamin biosynthesis, along with decreased functions associated with infectious bacterial diseases compared to the ETEC group. LA mitigates the adverse effects of ETEC infection in weaning mice, enhances growth performance and intestinal integrity, rebalances gut microbiota, and promotes beneficial metabolic functions. These findings validate the functionality of LA in a small animal model, supporting its potential application in improving the health and growth performance of weaning pigs.

The Mechanism of Zinc Oxide in Alleviating Diarrhea in Piglets after Weaning: A Review from the Perspective of Intestinal Barrier Function.

Weaning is one of the most challenging phases for piglets, and it is also the time when piglets are the most susceptible to diarrhea, which may result in significant economic losses for pig production. One of the dietary strategies for reducing post-weaning diarrhea (PWD) in piglets is to provide them with a pharmacological dose of zinc oxide (ZnO). However, excessive or long-term usage of high-dose ZnO has significant impacts on pig health and the ecological environment. Therefore, caution should be exercised when considering the use of high-dose ZnO for the prevention or treatment of PWD in piglets. In this paper, the significant role of zinc in animal health, the potential mode of action of ZnO in alleviating diarrhea, and the impact of innovative, highly efficient ZnO alternatives on the regulation of piglet diarrhea were reviewed to offer insights into the application of novel ZnO in pig production.

High casein concentration induces diarrhea through mTOR signal pathway inhibition in post-weaning piglets.

Weaning is one of the most challenging periods in a pig's life, during which piglets suffer from nutrition and other issues. Post-weaning diarrhea is one of the major health problems in the pig industry, leading to high morbidity and mortality rates. Previous studies have demonstrated that both the source and concentration of proteins are closely associated with post-weaning diarrhea in piglets. This study was conducted to prevent and control post-weaning diarrhea by selecting different dietary protein concentrations. To eliminate interference from other protein sources, casein was used as the only protein source in this study. Fourteen piglets (weighing 8.43 ± 0.3 kg, weaned on the 28th day) were randomly assigned to two dietary protein groups: a low-protein group (LP, containing 17% casein) and a high-protein group (HP, containing 30% casein). The experiment lasted 2 weeks, during which all piglets had ad libitum access to food and water. Diarrhea was scored on a scale from 1 to 3 (where 1 indicates normal stools and 3 indicates watery diarrhea), and growth performance measurements were recorded daily. The results showed that the piglets in the HP group had persistent diarrhea during the whole study, whereas no diarrhea was observed among piglets in the control group. The body weights and feed intake were significantly lower in piglets in the HP group compared to those in the LP group (p < 0.05). The gastrointestinal pH was significantly higher in piglets in the HP group than those in the LP group (p < 0.05). The intestinal tract microorganisms of the piglets in both groups were significantly affected by the protein concentration of the diet. A diet with high casein concentration significantly reduced the microbiota diversity. Compared to the LP group, the 30% casein diet decreased the abundance of Firmicutes, Bacteroidetes, and Actinobacteria at the phylum level and the relative abundance of Ruminococcus at the genus level. Diarrhea-related mRNA abundances were analyzed by the real-time polymerase chain reaction (PCR) in the intestine of piglets, and the results showed that the HP concentration markedly decreased the expression of solute carriers (SLC, p < 0.05). The mammalian target of rapamycin-mTOR signaling pathway (p < 0.01) was activated in the HP group. In conclusion, a high-protein diet induced post-weaning diarrhea, decreased growth performance, increased gastrointestinal pH, and reduced expression of solute carrier proteins. However, the relationship between high dietary casein feed and post-weaning diarrhea remains unclear and needs to be explored further.

Impact of adding eicosapentaenoic and docosahexaenoic acid-rich fish oil in sow and piglet diets on blood oxylipins and immune indicators of weaned piglets.

Weaning is a decisive event in piglets' life. This study aimed to evaluate whether the inclusion of fish oil, rich in eicosapentaenoic and docosahexaenoic acids (EPA and DHA), in sow and piglet diets, increased the concentration of anti-inflammatory molecules in the blood of weaned piglets and whether the effect was dependent on the pigs being born with either low or a high birth BW (bBW). Thirty-six sows in four consecutive batches were randomly distributed between a control diet with animal fat (15 g/kg in gestation and 30 g/kg in lactation) or a n-3 long-chain fatty acid diet (LCFA; totally or half replacing animal fat by fish oil during gestation and lactation, respectively) from service until weaning (ca. 28 days). At birth, the two lightest (LBW) and the two heaviest (HBW) piglets in each litter were identified and, at weaning, grouped in pens by pairs prioritising their bBW. Pens were further distributed into a control (30 g/kg animal fat) or n-3 LCFA diet (totally replacing animal fat by fish oil) for 28 days. At the end of the trial, blood was collected from piglets in the first batch (n = 48). Serum fatty acids (FAs) were quantified by GC, plasma oxylipins by ultra-HPLC-MS, and plasma immune indicators by ELISA. An interaction between piglet diet and bBW for average daily gain (P = 0.020) and average daily feed intake (P = 0.014) during the whole postweaning indicated that dietary n-3 LCFA-promoted LBW piglets to have a similar growth and intake than HBW piglets reaching 1.5 kg average BW more at the end of the postweaning period than LBW control piglets. Fish oil in piglet diets also increased the concentrations of total n-3 FA, EPA and DHA (all P < 0.001), their resultant oxylipins, particularly their hydroxy derivatives from lipoxygenase enzymatic pathway (all P < 0.001) and tended to increase immunoglobulin M (P = 0.067) in blood. Regarding the bBW category, LBW piglets tend to increase tumour necrosis factor α in plasma (P = 0.083) compared to HBW. It is concluded that fish oil in postweaning diets could enhance the daily gain and feed intake of LBW piglets, increasing the concentration of serum n-3 FAs and their derived oxylipins in plasma.

Impact of Nutritional Strategies to Prevent Post-Weaning Diarrhoea on Performance, Behaviour, and Microbiota in Piglets from Organic Farming.

Organic livestock farming is committed to high environmental and animal welfare standards, although pathologies such as post-weaning diarrhoea (PWD) may appear. The main objective of this study was to assess nutritional strategies to prevent PWD in organic piglets. A total of 134 weaned piglets were fed one of three diets: high crude protein (17.8%, HCP), low crude protein (16.8%, LCP), and low crude protein supplemented with liquid whey (LCP+W). Piglets were assessed weekly for four weeks on the following parameters: diarrhoea incidence, additional health parameters, average daily gain, and behaviour. Faecal samples were taken to analyse the intestinal microbiota composition. Data were analysed using LMM and GLMM models and Shannon and Whittaker indexes. No significant effect of diet on diarrhoea incidence was found, but the LCP+W diet increased average daily gain. Pigs fed the LCP+W diet presented a lower percentage of drinking and negative social behaviour compared with the HCP diet, and LCP pigs presented higher exploration compared with HCP. In addition, LCP+W piglets showed a higher abundance of the beneficial genus Frisingicoccus. Although liquid whey did not reduce diarrhoea incidence, the benefits found in growth, microbiota composition, and reduced negative social behaviour indicate that it could be an optimal supplement to organic diets.

Postweaning sodium citrate exposure induces long-lasting and sex-dependent effects on social behaviours in mice.

BACKGROUND: Postweaning is a pivotal period for brain development and individual growth. As an important chemical used in medicines, foods and beverages, sodium citrate (SC) is commonly available. Although some effects of SC exposure on individual physiology have been demonstrated, the potential long-lasting effects of postweaning dietary SC exposure on social behaviours are still elusive. METHODS: Both postweaning male and female C57BL/6 mice were exposed to SC through drinking water for a total of 3 weeks. A series of behavioural tests, including social dominance test (SDT), social interaction test (SIT), bedding preference test (BPT) and sexual preference test (SPT), were performed in adolescence and adulthood. After these tests, serum oxytocin (OT) levels and gut microbiota were detected. RESULTS: The behavioural results revealed that postweaning SC exposure decreased the social dominance of male mice in adulthood and female mice in both adolescence and adulthood. SC exposure also reduced the sexual preference rates of both males and females, while it had no effect on social interaction behaviour. ELISA results indicated that SC exposure decreased the serum OT levels of females but not males. 16S rRNA sequencing analysis revealed a significant difference in ß-diversity after SC exposure in both males and females. The correlation coefficient indicated the correlation between social behaviours, OT levels and dominant genera of gut microbiota. CONCLUSION: Our findings suggest that postweaning SC exposure may have enduring and sex-dependent effects on social behaviours, which may be correlated with altered serum OT levels and gut microbiota composition.

Effect of an organic acid blend as an antibiotic alternative on growth performance, antioxidant capacity, intestinal barrier function, and fecal microbiota in weaned piglets.

This study was conducted to evaluate the effects of dietary organic acid blend on growth performance, antioxidant capacity, intestinal barrier function, and fecal microbiota in weaned piglets compared with antibiotic growth promoters (AGPs). A total of 90 weaned crossbred barrows (24 ±â€…1 d of age) with an initial body weight of 7.40 kg were allocated into three experimental treatments. Each treatment consisted of six replicate pens, with five piglets housed in each pen. The dietary treatments included the basal diet (NC), the basal diet supplemented with antibiotics (PC), and the basal diet supplemented with organic acid blend (OA). On day 42, one piglet per pen was randomly selected for plasma and small intestinal sample collection. The results showed that dietary AGP significantly improved growth performance and reduced diarrhea incidence compared to the NC group (P < 0.05). Dietary OA tended to increase body weight on day 42 (P = 0.07) and average daily gain from days 0 to 42 (P = 0.06) and reduce diarrhea incidence (P = 0.05). Dietary OA significantly increased plasma catalase (CAT) activity and decreased the plasma concentration of malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin (IL)-8, and IL-6, which were accompanied by upregulated the relative mRNA abundance of superoxide dismutase 1 (SOD1), glutathione peroxidase 1 (GPX1), and nuclear factor erythroid 2-related factor 2 (NRF2) in comparison to that in the NC group (P < 0.05). Moreover, pigs fed the OA diet significantly increased the ratio of villus height to crypt depth and upregulated the relative expression of zonula occludens-1 (ZO-1) and Claudin1 gene in the jejunum compared to the NC group (P < 0.05). Interestingly, dietary AGP or OA did not affect the fecal microbiota structure or volatile fatty acid content (P > 0.05). In conclusion, our results suggested that dietary OA supplementation could improve growth performance and antioxidant capacity and protect the intestinal barrier of weaned piglets, therefore, it has the potential to be considered as an alternative to AGP in the pig industry.

In the era of antibiotics prohibition, there is an urgent need to develop green and efficient alternatives to antibiotics in the current pig industry to mitigate the economic losses associated with antibiotic bans. Organic acids (OA) are a class of substances that have long been used as feed additives due to their bacteriostatic properties, the ability of reducing feed pH, increasing the activity of digestive enzymes, and other beneficial effects. This study was conducted to evaluate the effects of dietary OA on growth performance, antioxidant capacity, intestinal barrier function, and fecal microbiota structure in weaned piglets. The results showed that OA supplementation can effectively improve the growth performance and intestinal health of weaned piglets. This study provides a reference for the application of OA as an alternative to antibiotics in weaned piglets.

Differences in enteric pathogens and intestinal microbiota between diarrheic weaned piglets and healthy penmates.

Postweaning diarrhea (PWD) is a multifactorial disease caused by different aetiological agents, like viruses or bacteria and where the role of the microbiota remains unclear. The aim of this study was to assess differences between healthy and diarrheic weaned pigs concerning the prevalence of pathogens and changes in the intestinal microbiota. Eighteen farms with PWD were selected and 277 fecal samples were collected (152 diarrheic vs 125 healthy). Presence of Rotavirus A (RVA), B (RVB), C (RVC) and Porcine Epidemic Diarrhea Virus (PEDV), virulence factors of Escherichia coli and Clostridioides difficile were analyzed by PCR. Finally, the microbiota composition was also study by 16 S rRNA sequencing on 148 samples (102 diarrheic vs 46 healthy). RVA (53.95 % vs 36 %, p=0.04) and RVB (49.67 % vs 28.8 %, p<0.001) were more frequent in diarrheic animals. Furthermore, RVA viral load was higher in diseased animals. VT2 toxin was significantly associated with diarrhea, whereas other virulence factors were not. Presence of C. difficile and PEDV was almost negligible. Regarding microbiota changes, Fusobacteriota phylum was more frequent in diarrheic samples and Ruminococcaceae family in healthy penmates. During the first week postweaning, Enterobacteriace and Campylobacteria were enriched in animals presenting diarrhea. Furthermore, Lactobacillus was detected in those individuals with no RVA infection. In conclusion, RVA seems to play a primary role in PWD. Classic E. coli virulence factors were not associated with diarrhea, indicating the need for revising their implication in disease. Moreover, Lactobacillus was found frequently in animals negative for RVA, suggesting some protective effect.

Gut microbiome and resistome characterization of pigs treated with commonly used post-weaning diarrhea treatments.

BACKGROUND: The global burden of antimicrobial resistance demands additional measures to ensure the sustainable and conscious use of antimicrobials. For the swine industry, the post-weaning period is critical and for many years, antimicrobials have been the most effective strategy to control and treat post-weaning related infections. Among them, post-weaning diarrhea causes vast economic losses, as it severely compromises piglets' health and growth performance. In this study, 210 piglets were transferred from a farm with recurrent cases of post-weaning diarrhea to an experimental farm and divided into six different treatment groups to determine the effect of the different treatments on the growth performance and survival, the microbiome, and the resistome in a cross-sectional and longitudinal study. The different treatments included antimicrobials trimethoprim/sulfamethoxazole, colistin, and gentamicin, an oral commercial vaccine, a control with water acidification, and an untreated control. An extra group remained at the farm of origin following the implemented amoxicillin routine treatment. A total of 280 fecal samples from pigs at four different sampling times were selected for metagenomics: before weaning-treatment at the farm of origin, and three days, two weeks, and four weeks post-treatment. RESULTS: The control group with water acidification showed a reduced death risk in the survival analyses and non-significant differences in average daily weight gain in comparison to the antibiotic-treated groups. However, the growth-promoting effect among antibiotic-treated groups was demonstrated when comparing against the untreated control group at the experimental farm. After four weeks of treatment, diversity indexes revealed significantly decreased diversity for the untreated control and the group that remained at the farm of origin treated with amoxicillin. For this last group, impaired microbial diversity could be related to the continuous amoxicillin treatment carried out at the farm. Analysis of the resistome showed that both gentamicin and amoxicillin treatments significantly contributed to the emergence of resistance, while trimethoprim/sulphonamide and colistin did not, suggesting that different treatments contribute differently to the emergence of resistance. CONCLUSIONS: Overall, this shotgun longitudinal metagenomics analysis demonstrates that non-antibiotic alternatives, such as water acidification, can contribute to reducing the emergence of antimicrobial resistance without compromising pig growth performance and gut microbiome.

Nutrition strategies to control post-weaning diarrhea of piglets: From the perspective of feeds.

Post-weaning diarrhea (PWD) is a globally significant threat to the swine industry. Historically, antibiotics as well as high doses of zinc oxide and copper sulfate have been commonly used to control PWD. However, the development of bacterial resistance and environmental pollution have created an interest in alternative strategies. In recent years, the research surrounding these alternative strategies and the mechanisms of piglet diarrhea has been continually updated. Mechanically, diarrhea in piglets is a result of an imbalance in intestinal fluid and electrolyte absorption and secretion. In general, enterotoxigenic Escherichia coli (ETEC) and diarrheal viruses are known to cause an imbalance in the absorption and secretion of intestinal fluids and electrolytes in piglets, resulting in diarrhea when Cl- secretion-driven fluid secretion surpasses absorptive capacity. From a perspective of feedstuffs, factors that contribute to imbalances in fluid absorption and secretion in the intestines of weaned piglets include high levels of crude protein (CP), stimulation by certain antigenic proteins, high acid-binding capacity (ABC), and contamination with deoxynivalenol (DON) in the diet. In response, efforts to reduce CP levels in diets, select feedstuffs with lower ABC values, and process feedstuffs using physical, chemical, and biological approaches are important strategies for alleviating PWD in piglets. Additionally, the diet supplementation with additives such as vitamins and natural products can also play a role in reducing the diarrhea incidence in weaned piglets. Here, we examine the mechanisms of absorption and secretion of intestinal fluids and electrolytes in piglets, summarize nutritional strategies to control PWD in piglets from the perspective of feeds, and provide new insights towards future research directions.

Effects of increasing dietary arginine supply during the three first weeks after weaning on pig growth performance, plasma amino acid concentrations, and health status.

A total of 425 weaned pigs (Exp. 1: 225 pigs [5.8 ±â€…0.9 kg]; Exp. 2: 200 pigs [6.1 ±â€…1.2 kg]) were used to determine the optimal dietary standardized ileal digestible (SID) arginine (Arg) level in early nursery diets based on growth and health responses. The basal diet in Exp.1 was formulated to meet SID Arg recommendation (0.66%; NRC, 2012) and in Exp. 2, SID Arg was set to simulate current industry practices for feeding nursery pigs (1.15 %). Basal diets were supplemented with 0.3%, 0.6%, 0.9%, and 1.2% of l-arginine to provide five levels of dietary SID Arg. Experimental diets were fed during phases I (days 0 to 7) and II (days 8 to 21) with common diets until market. Feed disappearance and body weight (BW) were measured on days 7, 14, 21, and 43. Final BW was recorded at first removal of pigs for market. Pen fecal score was assigned daily from days 0 to 21. Plasma immunoglobulin A (IgA) was determined on days 0, 7, and 14 and amino acids (AAs) concentration and plasma urea nitrogen (PUN) on days 0 and 14. Orthogonal polynomial contrasts were used to determine the linear and quadratic effects of dietary Arg. Optimal SID Arg was determined by fitting the data with piecewise regression, using growth performance as the primary response variable. In Exp. 1, dietary Arg linearly increased (P < 0.1) BW, average daily gain (ADG), and gain to feed ratio (G:F) ratio on day 21, as well as reduced (χ2 = 0.004) the percentage of pigs that lost weight (PLW) in week 1 by 29%. Dietary Arg resulted in linear improvement (P = 0.082) of ADG for the overall nursery period and quadratic improvement (P < 0.1) of final BW at marketing. In Exp. 2, dietary Arg linearly increased (P < 0.05) ADG and average daily feed intake (ADFI) in week 1, BW and ADFI (P < 0.1) on day 14, as well as reduced (χ2 ≤ 0.001) PLW in week 1. From days 0 to 21, G:F was improved quadratically (P < 0.1). Dietary Arg linearly increased (P < 0.1) ADG and BW on day 43. Dietary Arg supplementation decreased the incidence (χ2 < 0.05) of soft and watery feces during the first weeks after weaning and lower concentration of plasma IgA on days 7 and 14. Dietary Arg linearly and/or quadratically influenced plasma AA concentrations (P < 0.05), including an increase in Arg, Leu, Phe, Val, citrulline, ornithine, and PUN concentrations. Overall, weaned pigs exhibit optimal nursery growth performance and health when provided with dietary SID Arg ranging from 1.5% to 1.9%. This dietary range contributes to a reduction in the occurrence of fall-back pigs and improvements in final BW at marketing.

Burlap and buddies: the effects of social enrichment (preweaning mixing) and object enrichment (burlap) on piglet behavior and welfare in the postweaning environment.

The process of weaning piglets in commercial swine operations subjects them to numerous abrupt and stressful changes often resulting in negative welfare consequences. The objective was to study the postweaning effects of early-life (1 to 3 d of age) preweaning socialization in multi-litter groups as well as object enrichment (burlap sheet) in the pre- and postweaning environment by comparing six treatments that combined mixing of one vs. two vs. four litters mixed preweaning with and without burlap provision. An ANOVA linear model was run on all normal data, expressed per experimental unit (and behavior data were averaged over time), while non-normal data were analyzed using the Kruskal-Wallis test. Non-enriched groups of piglets were observed manipulating pen objects more often than the enriched groups (P = 0.005). Biting behaviors, including the chewing of ears and tails of pen-mates but excluding fighting, were observed the least in groups of pigs of four litters mixed preweaning, while piglets that were not mixed preweaning were observed biting the most (P = 0.03). Piglets who were not mixed preweaning also manipulated the burlap more frequently than the piglets from groups of 4 litters mixed preweaning (P = 0.02). Biting (P < 0.001) and displacements (P = 0.03) and fighting (P = 0.002) throughout the pen were observed less in the enriched groups. There were fewer lesions per pig in the enriched groups vs. non-enriched groups initially (P = 0.07) and 1 wk after weaning (P = 0.10). Furthermore, pigs mixed in groups of four litters preweaning also tended to have lower lesion scores (P = 0.07) 1-wk postweaning compared to the other treatments. However, there were no differences between treatments in the proportion of piglets resting, eating/drinking, being active, or using the burlap, or for the observed frequency of displacements at the feeder, social behaviors, or belly nosing (P > 0.10). Overall, social enrichment encourages socialization with unfamiliar conspecifics at a younger age while object enrichment allows pigs to redirect their attention toward objects such as burlap. Both may improve pig behavior and welfare after weaning.

The role of gender differences in the outcome of juvenile social isolation: Emphasis on changes in behavioral, biochemical and expression of nitric oxide synthase genes alteration.

Social isolation can cause serious problem in performance of individuals in community. As gender differences may cause variation results in the severity of depressive behavior and response of patients to therapy, the impact of gender and the interaction of the level of endocrine secretion in depression were investigated in this study. Wistar rats of both sexes were subjected to post-weaning social isolation (PWSI) conditions and, together with the control group, experienced several behavioral tests including open-field Test (OFT), elevated plus maze (EPM), force swimming test (FST), splash test and novel object recognition test (NOR). Hippocampal tissue was isolated to measure biochemical factors such as nitric oxide level, FRAP amount, MDA level. In addition, real-time-PCR test was used to quantify the genes expression level of inducible nitric oxide synthase (iNOS) and neuronal nitric oxide synthase (nNOS). On the other hand, sexual hormone levels in blood were measured. Both cognitive and behavioral f unctions were declined as the result of PWSI induction in male and diestrus female rats. The consequent surge of estradiol during estrous phase seems to suppress the accumulation of reactive oxygen species (ROS), and modulate iNOS and nNOS expression. In conclusion, while the pattern of PWSI in surge cellular antioxidants, raising cellular ROS level is gender-specific, this alleviation was in relation with the drop of estradiol and unrelated with testosterone level.

From land to ocean: One month for southern elephant seal pups to acquire aquatic skills prior to their first departure to sea.

Weaned southern elephant seals (SES) quickly transition from terrestrial to aquatic life after a 5- to 6-week post-weaning period. At sea, juveniles and adult elephant seals present extreme, continuous diving behaviour. Previous studies have highlighted the importance of the post-weaning period for weanlings to prepare for the physiological challenges of their future sea life. However, very little is known about how their body condition during this period may influence the development of their behaviour and brain activities. To characterise changes in the behavioural and brain activity of weanlings prior to ocean departure, we implemented a multi-logger approach combining measurements of movements (related to behaviour), pressure (related to diving), and brain electrical activity. As pups age, the amount of time allocated to resting decreases in favour of physical activity. Most resting (9.6 ± 1.2 h/day) takes place during daytime, with periods of slow-wave sleep representing 4.9 ± 0.9 h/day during the first 2 weeks. Furthermore, an increasing proportion of physical activity transitions from land to shore. Additionally, pups in poorer condition (lean group) are more active earlier than those in better condition (corpulent group). Finally, at weaning, clear circadian activity with two peaks at dawn and dusk is observed, and this pattern remains unchanged during the 4 weeks on land. This circadian pattern matches the one observed in adults at sea, with more prey catches at dawn and dusk, raising the question of whether it is endogenous or triggered by the mother during lactation.

Comparative Analysis of Intestinal Inflammation and Microbiota Dysbiosis of LPS-Challenged Piglets between Different Breeds.

Post-weaning diarrhea is common in piglets, causing huge economic losses worldwide. Associations between LPS challenge, intestinal inflammation, and microbiota have been reported in Duroc × Landrace × Yorkshire (DLY) crossbred pigs. However, the effects of LPS challenge in other breeds remain unclear. In the current study, we performed a comprehensive comparative analysis of the effects of LPS challenge on jejunal mucosal morphology, jejunal microbial composition, and serum indexes in two pig breeds: DLY and Heigai, an indigenous Chinese breed. The results showed that LPS caused considerable damage to the mucosal morphology, enhanced serum levels of inflammatory cytokines and the intestinal permeability index, and lowered the antioxidant capacity index. LPS challenge also changed the microbial composition and structure of the jejunum, significantly increased the abundances of Escherichia-Shigella in DLY pigs, and decreased those of Gemella and Saccharimonadales in Heigai pigs. Furthermore, LPS challenge triggered functional changes in energy metabolism and activities related to the stress response in the jejunal bacterial community, alleviating the inflammatory response in Heigai pigs. This study also revealed that Heigai pigs had a weaker immune response to LPS challenge than DLY pigs, and identified several genera related to the breed-specific phenotypes of Heigai pigs, including Gemella, Saccharimonadales, Clostridia_UCG_014, Terrisporobacter, and Dielma. Our collective findings uncovered differences between Heigai and DLY pigs in intestinal inflammation and microbiota dysbiosis induced by LPS challenge, providing a theoretical basis for unraveling the mechanism of intestinal inflammation in swine and proposing microbial candidates involved in the resistance to diarrhea in piglets.

Towards identification of new genetic determinants for post-weaning diarrhea in piglets.

Post-weaning diarrhea in pigs is a considerable challenge in the pig farming industry due to its effect on animal welfare and production costs, as well as the large volume of antibiotics, which are used to treat diarrhea in pigs after weaning. Previous studies have revealed loci on SSC6 and SSC13 associated with susceptibility to specific diarrhea causing pathogens. This study aimed to identify new genetic loci for resistance to diarrhea based on phenotypic data. In depth clinical characterization of diarrhea was performed in 257 pigs belonging to two herds during the first 14 days post weaning. The daily diarrhea assessments were used for the classification of pigs into case and control groups. Pigs were assigned to case and control groups based only on the incidence of diarrhea in the second week of the study in order to differentiate between differences in etiology. Genome-wide association studies and metabolomics association analysis were performed in order to identify new biological determinants for diarrhea susceptibility. With the present work, we revealed a new locus for diarrhea resistance on SSC16. Furthermore, studies of metabolomics in the same pigs revealed one metabolite associated with diarrhea.

Characterization of Antimicrobial Resistance in Escherichia coli Isolated from Diarrheic and Healthy Weaned Pigs in Catalonia.

Postweaning diarrhea (PWD) is a multifactorial concern in the swine industry that leads to high antibiotic consumption, usually without testing susceptibility, increasing the risk of the selection of Escherichia coli-resistant strains. In this study, 251 E. coli strains isolated from fecal samples of diarrheic (n = 148) and apparently healthy piglets (n = 103) in farms in Catalonia were tested against their susceptibility to fourteen different antimicrobials. The phenotypic antimicrobial resistance (AMR) testing revealed high levels of AMR, with 41.4% of the isolates presenting a multidrug-resistant (MDR) profile. More specifically, resistance to class D (prudence) antimicrobials such as erythromycin (99.6%), amoxicillin (95.2%), streptomycin (91.6%), tetracycline (88.8%), lincospectin (64.5%), and sulfamethoxazole/trimethoprim (60%) was very high, as well as to class C (caution) antimicrobials such as florfenicol (45%). A special concern was observed for antimicrobial category B (restrict), like quinolones and colistin, that both presented a high rate of resistance. Colistin use was substantially reduced in Spain, but resistance is still present in weaned pigs, presenting a MIC90 of 4 µg/mL. This suggests that reducing antibiotic use is not enough to eliminate this AMR. Finally, it was found that piglets suffering diarrhea were more commonly carriers of MDR strains than the healthy ones (49.3% vs. 35%, p = 0.031). Therefore, given the high rates of resistance to the most commonly used antimicrobials, especially in diseased pigs, a new non-antibiotic-based approach should be implemented for the management of PWD.

Purine Metabolism and Hexosamine Biosynthetic Pathway Abnormalities in Diarrheal Weaned Piglets Identified Using Metabolomics.

Post-weaning diarrhea significantly contributes to the high mortality in pig production, but the metabolic changes in weaned piglets with diarrhea remain unclear. This study aimed to identify the differential metabolites in the urine of diarrheal weaned piglets and those of healthy weaned piglets to reveal the metabolic changes associated with diarrhea in weaned piglets. Nine 25-day-old piglets with diarrhea scores above 16 and an average body weight of 5.41 ± 0.18 kg were selected for the diarrhea group. Corresponding to the body weight and sex of the diarrhea group, nine 25-month-old healthy piglets with similar sex and body weights of 5.49 ± 0.21 kg were selected as the control group. Results showed that the serum C-reactive protein and cortisol of piglets in the diarrhea group were higher than those in the control group (p < 0.05). The mRNA expression of TNF-α, IFN-γ in the jejunum and colon, and IL-1ß in the jejunum were increased in diarrhea piglets (p < 0.05), accompanied by a reduction in the mRNA expression of ZO-1, ZO-2, and CLDN1 in the jejunum and colon (p < 0.05); mRNA expression of OCLN in the colon also occurred (p < 0.05). Metabolomic analysis of urine revealed increased levels of inosine, hypoxanthine, guanosine, deoxyinosin, glucosamine, glucosamine-1-p, N-Acetylmannosamine, chitobiose, and uric acid, identified as differential metabolites in diarrhea piglets compared to the controls. In summary, elevated weaning stress and inflammatory disease were associated with the abnormalities of purine metabolism and the hexosamine biosynthetic pathway of weaned piglets. This study additionally indicated the presence of energy metabolism-related diseases in diarrheal weaned piglets.

Detection of mcr-1-1 Positive Enteropathogenic Escherichia coli Isolates Associated with Post-Weaning Diarrhoea in an Organic Piglet-Producing Farm in Austria.

Postweaning diarrhoea (PWD) is a frequent multifactorial disease occurring in swine stocks worldwide. Since pathogenic Escherichia (E.) coli play a pivotal role in the pathogenesis of PWD and porcine E. coli are often resistant to different antibiotics, colistin is frequently applied to treat piglets with PWD. However, the application of colistin to livestock has been associated with the emergence of colistin resistance. This case report describes the detection of the colistin resistance gene mcr-1-1 in two E. coli isolated from piglets with PWD in an Austrian organic piglet-producing farm, which was managed by two farmers working as nurses in a hospital. Both mcr-1-positive E. coli were further analysed by Illumina short-read-sequencing, including assemblies and gene prediction. Both isolates belonged to the same clonal type and were positive for eaeH and espX5, which are both virulence genes associated with enteropathogenic E. coli (EPEC). Due to the detection of mcr-1-positive EPEC and based on the results of the antimicrobial resistance testing, the veterinarian decided to apply gentamicin for treatment instead of colistin, leading to improved clinical signs. In addition, after replacing faba beans with whey, PWD was solely observed in 2/10 weaned batches in the consecutive months.