Dietary supplementation of benzoic acid and essential oils combination enhances intestinal resilience against LPS stimulation in weaned piglets

Background The benefits of combining benzoic acid and essential oils(BAO)to mitigate intestinal impairment during the weaning process have been well established,while the detailed underlying mechanism has not been fully elucidated.Previous research has primarily focused on the reparative effects of BAO on intestinal injury,while neglecting its potential in enhancing intestinal stress resistance.Methods In this study,we investigated the pre-protective effect of BAO against LPS-induced stress using a modified experimental procedure.Piglets were pre-supplemented with BAO for 14 d,followed by a challenge with LPS or saline to collect blood and intestinal samples.Results Our findings demonstrated that BAO supplementation led to significant improvements in piglets’final weight,average daily gain,and feed intake/body gain ratio.Additionally,BAO supplementation positively influenced the composition of intestinal microbiota,increasing beneficial Actinobacteriota and Alloprevotella while reducing harmful Desulfobacterota,Prevotella and Oscillospira.Furthermore,BAO supplementation effectively mitigated oxidative disturbances and inflammatory responses induced by acute LPS challenge.This was evidenced by elevated levels of T-AOC,SOD,and GSH,as well as decreased levels of MDA,TNF-α,and IL-6 in the plasma.Moreover,piglets subjected to LPS challenge and pre-supplemented with BAO exhibited significant improvements in intestinal morphological structure and enhanced integrity,as indicated by restored expression levels of Occludin and Claudin-1 compared to the non-supplemented counterparts.Further analysis revealed that BAO supplementation enhanced the jejunal antioxidative capacity by increasing GSH-Px levels and decreasing MDA levels under the LPS challenge and stimulated the activation of the Nrf2 signaling pathway.Additionally,the reduction of TLR4/NF-κB/MAPK signaling pathways activation and proinflammatory factor were also observed in the jejunal of those piglets fed with BAO.Conclusions In summary,our study demonstrates that pre-supplementation of BAO enhances the anti-stress capacity of weaned piglets by improving intestinal microbiota composition,reinforcing the intestinal barrier,and enhancing antioxidative and anti-inflammatory capabilities.These effects are closely associated with the activation of Nrf2 and TLR4/NF-κB/MAPK signaling pathways.

Dietary fibers with low hydration properties exacerbate diarrhea and impair intestinal health and nutrient digestibility in weaned piglets

Background:This study aimed to investigate the hydration properties of different-source fibrous materials by com-paring their water-binding capacity(WBC),water swelling capacity(WSC),viscosity,and in vivo effects of selected samples on growth performance,nutrient digestibility,diarrhea,and intestinal health in weaned piglets.Methods:A total of 13 commercially available fibrous materials were first compared in chemical composition and in vitro hydration property.Subsequently,40 weaned piglets were randomized to five experimental dietary groups(8 piglets per group):control diet(a basal diet without dietary fiber,CON),basal diet supplemented with 5%microcrys-talline cellulose(MCC),5%wheat bran(WB),5%Moringa oleifera leaf powder(MOLP),or 5%sugar beet pulp(SBP),fol-lowed by analyzing their growth performance and diarrhea rate in a 28-d experiment.After the feeding experiment,anaesthetized piglets were killed,and their intestinal and colon content or plasma samples were analyzed in nutrient digestibility,intestinal morphology,intestinal barrier,short-chain fatty acids(SCFAs),and bacterial population.Results:In vitro studies showed low hydration properties for WB and MCC,while medium hydration properties for MOLP and SBP.In vivo studies indicated that compared with medium hydration property groups,low hydration prop-erty groups showed(1)exacerbated diarrhea,impaired intestinal health,and reduced apparent fecal digestibility of dry matter,gross energy,acid detergent fiber,and neutral detergent fiber;(2)decreased SCFAs concentration and rela-tive levels of Lactobacillus and Bifidobacterium,but increased levels of Escherichia coli and Brachyspira hyodysenteriae in colon contents.Additionally,SBP showed optimal performance in reducing diarrhea and increasing SCFAs produc-tion.Correlation analysis revealed a positive correlation of fiber hydration properties with in vitro SCFAs production,and diarrhea index and nutrient digestibility were negatively and positively correlated with SCFAs levels in the colon contents of weaned piglets,respectively.Conclusions:Different-source dietary fibers varied in their hydration properties and impacts on diarrhea,microbial composition and SCFAs production in weaned piglets.WB and MCC could exacerbate diarrhea and impair nutrient digestibility,probably because their low hydration properties were detrimental to gut microbial homeostasis and fermentation.Our findings provide new ideas for rational use of fiber resources in weaned piglets.

Effects of lactic acid bacteria-fermented formula milk supplementation on ileal microbiota,transcriptomic profile,and mucosal immunity in weaned piglets

Background:Lactic acid bacteria(LAB)participating in milk fermentation naturally release and enrich the fermented dairy product with a broad range of bioactive metabolites,which has numerous roles in the intestinal health-promot-ing of the consumer.However,information is lacking regarding the application prospect of LAB fermented milk in the animal industry.This study investigated the effects of lactic acid bacteria-fermented formula milk(LFM)on the growth performance,intestinal immunity,microbiota composition,and transcriptomic responses in weaned piglets.A total of 24 male weaned piglets were randomly divided into the control(CON)and LFM groups.Each group consisted of 6 replicates(cages)with 2 piglets per cage.Each piglet in the LFM group were supplemented with 80 mL LFM three times a day,while the CON group was treated with the same amount of drinking water.Results:LFM significantly increased the average daily gain of piglets over the entire 14 d(P<0.01)and the average daily feed intake from 7 to 14 d(P<0.05).Compared to the CON group,ileal goblet cell count,villus-crypt ratio,sIgA,and lactate concentrations in the LFM group were significantly increased(P<0.05).Transcriptomic analysis of ileal mucosa identified 487 differentially expressed genes(DEGs)between two groups.Especially,DEGs involved in the intestinal immune network for IgA production pathways,such as polymeric immunoglobulin receptor(PIGR),were significantly up-regulated(P<0.01)by LFM supplementation.Moreover,trefoil factor 2(TFF2)in the LFM group,one of the DEGs involved in the secretory function of goblet cells,was also significantly up-regulated(P<0.01).Sequenc-ing of the 16S rRNA gene of microbiota demonstrated that LFM led to selective enrichment of lactate-producing and short-chain fatty acid(SCFA)-producing bacteria in the ileum,such as an increase in the relative abundance of Entero-coccus(P=0.09)and Acetitomaculum(P<0.05).Conclusions:LFM can improve intestinal health and immune tolerance,thus enhancing the growth performance of weaned piglets.The changes in microbiota and metabolites induced by LFM might mediate the regulation of the secretory function of goblet cells.

Dietary garcinol supplementation improves diarrhea and intestinal barrier function associated with its modulation of gut microbiota in weaned piglets

Background:The effects of dietary garcinol on diarrhea and intestinal barrier function associated with its modulation of gut microbiota in weaned piglets were investigated.Method:One hundred forty four weaned piglets(Duroc×Yorkshire×Landrace)from 16 pens(9 piglets per pen)were randomly divided into four treatment groups:controls(CON)or those supplemented with 200 mg/kg(LOW),400 mg/kg(MID),or 600 mg/kg(HIGH)diet garcinol.After 14-day trial,three piglets per pen were chosen to collect plasma,intestinal tissue and colonic digesta samples.Results:We demonstrated for the first time that garcinol promoted growth performance,as increased average daily feed intake(ADFI)and decreased feed/gain ratio(F/G);and reduced diarrhea incidence(P<0.05);and strengthened antioxidant capacity,as an increased antioxidative index(P<0.05).Additionally,garcinol ameliorated intestinal barrier dysfunction,as an increased villus height to crypt depth ratio,increased zonula occludens protein 1(ZO-1),occludin and claudin-1 expression in the jejunum and ileum(P<0.05),and decreased intestinal permeability(P<0.05);and reduced inflammation,as decreased cytokine interleukin(IL)-6,IL-10,IL-1βand tumor necrosis factor-α(TNF-α)levels in the mucosa of the jejunum and ileum,and NF-κB p65 translocation(P<0.05).Moreover,garcinol inhibited the growth of most harmful bacteria in the gut,especially Escherichia coli,and increased the growth of the beneficial bacteria Lactobacillus.Conclusion:This work provides a fundamental basis for the future development of garcinol-functional food use for improving diarrhea and intestinal barrier function in weaned piglets and for understanding the biological effects of garcinol and its potential as a functional feed additive.

The effect of dietary tryptophan levels on oxidative stress of liver induced by diquat in weaned piglets

Oxidative stress can induce abnormal tryptophan metabolism. The present study was mainly conducted to determine the effect of dietary tryptophan levels on oxidative stress in the liver of weaned pigs challenged by diquat. A total of 36 PIC piglets weaned at 21 days of age were randomly allotted to 1 of 3 diets containing dietary tryptophan levels of 0.18, 0.30, and 0A5% for 14 d. On day 8, the piglets were injected intraperitoneally with sterile 0.9% NaCI solution or diquat （10 mg/kg body weight）. During the first 7 d of trial, increasing dietary tryptophan levels enhanced average daily gain （P = 0.09） and average daily feed intake （P = 0.08）, and decreased the feed efficiency （P 〈 0.05） of piglets. The growth performance was decreased by diquat injection （P 〈 0.05）. Diquat injection also decreased the activities of the superoxide dismutase （SOD） and glutathione peroxidase （GPx） in the plasma and liver （P 〈 0.05）, increased plasma malondialdehyde （MDA） （P 〈 0.05） and urea nitrogen （P 〈 0.05） concentrations, and enhanced MDA concentration （P = 0.09） and tryptophan 2,3-dioxygenase （TDO） activity （P = 0.07） in liver of piglets. Increasing dietary tryptophan levels could attenuate the effects of diquat injection on the MDA （P = 0.06） concentration and the activities of SOD （P = 0.09） and GPx （P = 0.05） of the liver, and plasma urea nitrogen （P = 0.06） concentration in the piglet. There was a synergistic role for increasing TDO activity in the liver between dietary tryptophan levels and diquat injection （P 〈 0.05）. These results suggest that increasing dietary tryptophan levels could attenuate the oxidative stress of the liver in weaned piglets intraperitoneally injected with diquat via enhancing the antioxidant capacity.

Effect of Dietary Supplementation with Hydrolyzed Wheat Gluten on Growth Performance, Cell Immunity and Serum Biochemical Indices of Weaned Piglets (Sus scrofa)

To investigate the effects of dietary supplementation with hydrolyzed wheat gluten （HWG） on growth performance, cell immunity and serum biochemical indices of weaned piglets, 160 crossed （Large White×andrace） and weaned piglets were randomly divided into 4 treatments with 4 replicates of 10 piglets each. The piglets in each treatment were fed an experimental diet containing either 0 g kg-1 HWG （control group）, 30 g kg-1 HWG （3% HWG group）, 50 g kg-1 HWG （5% HWG group）, or 2.5 g kg-1 glycyl-L-glutamine （0.25% Gly-Gln group）. The results showed that the diarrhea rates in 3% HWG and 5% HWG groups were significantly lower than in control group from d 1 to 14 （P〈0.05）, while the average daily gain （ADG） in each of two groups was increased （P〉0.05）. When compared with control group, dietary supplementation with 3% HWG increased the ratio of CD4＋：CD8＋ and the ratio of serum albumin and globulin concentrations （A：G） on d 14 and 28, as well as the proliferation of T- and B-lymphocytes （P〉0.05） on d 28. In addition, on d 14 and 28, the A：G ratio in 5% HWG group was significantly higher than in control group （P〈0.05）, while the ratio of CD4＋：CD8＋ increased slightly （P〉0.05）. Interestingly, 0.25% Gly-Gln group had higher proportion of CD3＋ （P〉0.05） and CD4＋ （P〈0.05） on d 14 than control group, but growth performances of 0.25% Gly-Gln group were negatively affected at all experiment stages. These results suggested that HWG might improve the growth performance of piglets by strengthening cell immunity and decreasing the occurrence of diarrhea during the prophase after weaning.

Tannic acid prevents post-weaning diarrhea by improving intestinal barrier integrity and function in weaned piglets

Background:Tannic acid(TA)is potential to reduce diarrhea in weaning pigs,but knowledge about the influence of TA on intestinal barrier integrity and function is still scarce.This experiment was conducted to investigate the effects of dietary TA supplementation on growth performance,diarrhea rate,intestinal barrier integrity and function of weaned pigs.Methods:A total of 108 crossbred(Duroc×Landrace×Yorkshire)piglets,with an initial average body weight of 6.60±0.27 kg,were allotted to 3 groups(6 pigs/pen and 6 replicates/group)in a randomized complete block design according to their gender and body weight.Piglets were fed the basal diet with 0(control,CON),0.2%and 1.0%TA,respectively.The trial lasted for 28 d.Results:Compared with the CON group,dietary 0.2%and 1.0%TA supplementation didn’t affect ADFI,ADG and F:G(P>0.05),but reduced diarrhea rate,diarrhea index and diarrhea score of piglets(P<0.05),reduced diamine oxidase(DAO)activity and D-lactic acid concentration in serum(P<0.01).The higher occludin expression and localization were observed in the duodenum,jejunum and ileum after supplementation with 0.2%or 1.0%TA(P<0.05).Adding 0.2%TA to diet significantly decreased crypt depth,increased villus height/crypt depth ratio in the duodenum(P<0.05),and dietary 1.0%TA tended to decrease crypt depth(P<0.10)and significantly decreased villus height(P<0.05)of the ileum.Moreover,lower malondialdehyde content in the ileum was detected in the pigs fed 1.0%TA(P<0.05).In the duodenum,both 0.2%and 1.0%TA groups had higher occludin(OCLN)mRNA and 0.2%TA group had higher zonula occludens-2(ZO-2)level(P<0.05).Meanwhile,dietary 1.0%TA supplementation tended to up-regulate OCLN mRNA levels in the jejunum(P<0.10)and 0.2%TA supplementation tended to up-regulate zonula occludens-1(ZO-1)mRNA levels in the ileum(P<0.10).Conclusion:In conclusion,dietary supplementation of 0.2%or 1.0%TA could effectively alleviate postweaning diarrhea without altering growth performance in weaned piglets,which might be achieved by improving intestinal barrier integrity and function.

Effect of yeast Saccharomyces cerevisiae supplementation on serum antioxidant capacity, mucosal sIgA secretions and gut microbial populations in weaned piglets

This study was conducted to determine the effect of different forms of yeasts Saccharomyces cerevisiae supplementation on serum antioxidant capacity, mucosal secretory immunoglobulin A（s Ig A） secretions and gut microbial populations in weaned piglets. A total of 96 piglets weaned at 14 d of age were randomly allotted to 4 dietary treatments：（1） basal diet without yeast（Control）;（2） basal diet supplemented with 3.00 g kg–1 live yeast（LY）;（3） basal diet supplemented with 2.66 g kg–1 heat-killed whole yeast（HKY）; and（4） basal diet supplemented with 3.00 g kg–1 superfine yeast powders（SFY）. Each treatment had 4 replicates（pens）, with 6 piglets per replicate. The experiment lasted for 3 wk. At d 7 and 21 of the experiment, the samples of serum, mucosa and mesenteric lymph node（MLN） from jejunum, and digesta from the ileum and cecum were collected for determinations. Compared with the Control, dietary SFY supplementation increased serum superoxide dismutase（SOD） activity and lysozyme levels at d 7, and jejunum mucosal s Ig A secretions at d 21 of the experiment（P〈0.05）. Dietary LY supplementation increased serum SOD activity and jejunum mucosal s Ig A secretions, but decreased serum malondialdehyde（MDA） concentration at d 7 and 21（P〈0.05）. Piglets fed diets supplemented with LY and SFY had lower p H values and decreased numbers of Escherichia coli in the ileum and cecum contents at d 21 compared with the Control（P〈0.05）. Moreover, the ratio of Lactobacilli to E. coli in the ileum and cecum contents was increased by dietary LY and SFY supplementations（P〈0.05）. Collectively, different forms of yeasts, especially LY and SFY, may modulate body antioxidant capacity and enhance the intestinal immunity by regulation of secretions of mucosal s Ig A and reduction of pathogenic bacteria colonization, thus improving intestinal health of weaned piglets.

Administration of Saccharomyces boulardii mafic-1701 improves feed conversion ratio,promotes antioxidant capacity,alleviates intestinal inflammation and modulates gut microbiota in weaned piglets

Background:Probiotics are used as a means to improve animal health and intestinal development.Saccharomyces boulardii is a well-known probiotic;however,few studies have examined the effects of S.boulardii on weaned piglet performance.Therefore,this 28-day study compared the effects of S.boulardii mafic-1701 and aureomycin in diets for weaned piglets on growth performance,antioxidant parameters,inflammation and intestinal microbiota.One hundred and eight piglets,weaned at 28 d of age(8.5±1.1 kg),were randomly divided into the three dietary treatment groups with six pens and six piglets per pen(half male and half female).The dietary treatment groups were as follows:1)basal diet(CON);2)basal diet supplemented with 75 mg/kg aureomycin(ANT);3)basal diet supplemented with 1×108 CFU/kg S.boulardii mafic-1701(SB).Results:Compared to CON group,SB group had higher feed efficiency(P<0.05)in the last 14 d and lower diarrhea rate(P<0.05)over the entire 28 d.Total superoxide dismutase in serum was markedly increased in SB group(P<0.05).Moreover,compared with CON group,SB group decreased the levels of pro-inflammatory cytokines interleukin-6(P<0.01)and Tumor necrosis factor-α(P<0.05)in jejunum.Supplementation of S.boulardii mafic-1701 increased the abundance of Ruminococcaceae_UCG_009 and Turicibacter(P<0.05),whereas the abundance of unclassified_Clostridiaceae_4 was decreased(P<0.05).Furthermore,S.boulardii mafic-1701 administration increased cecal concentration of microbial metabolites,isobutyrate and valerate(P<0.05).Conclusions:The improvement in feed conversion ratio,reduction in diarrhea rate in weaned piglets provided diets supplemented with S.boulardii mafic-1701 may be associated with enhanced antioxidant activity,antiinflammatory responses and improved intestinal microbial ecology.

Comparative effects of enzymatic soybean,fish meal and milk powder in diets on growth performance,immunological parameters,SCFAs production and gut microbiome of weaned piglets

Background:The objective of this study was to evaluate the replacement effects of milk powder(MK)and fish meal(FM)by enzymatic soybean(ESB)in diets on growth performance,immunological parameters,SCFAs production and gut microbiome of weaned piglets.Methods:A total of 128 piglets with initial body weight at 6.95±0.46 kg,were randomly assigned into 4 dietary treatments with 8 replicates per treatment and 4 piglets per replicate for a period of 14 d.Piglets were offered isonitrogenous and iso-energetic diets as follows:CON diet with MK and FM as high quality protein sources,ESB plus FM diet with ESB replacing MK,ESB plus MK diet with ESB replacing FM,and ESB diet with ESB replacing both MK and FM.Results:No significant differences were observed in growth performance among all treatments(P>0.05).However,piglets fed ESB plus FM or ESB diet had increased diarrhea index(P<0.01),and lower digestibility of dry matter(DM),gross energy(GE)or crude protein(CP),relative to piglets fed CON diet(P<0.01).Moreover,the inclusion of ESB in diet markedly decreased the plasma concentration of HPT and fecal concentration of butyric acid(BA)(P<0.01).The High-throughput sequencing of 16S rRNA gene V3−V4 region of gut microbiome revealed that the inclusion of ESB in diet increased the alpha diversity,and the linear discriminant analysis effect size(LEfSe)showed that piglets fed with ESB plus FM or ESB diet contained more gut pathogenic bacteria,such as g_Peptococcus,g_Veillonella and g_Helicobacter.Conclusion:The inclusion of ESB in diet did not markedly affect growth performance of piglets,but the replacement of MK or both MK and FM by ESB increased diarrhea index,which could be associated with lower nutrients digestibility and more gut pathogenic bacteria.However,piglets fed diet using ESB to replace FM did not markedly affect gut health-related parameters,indicating the potential for replacing FM with ESB in weaning diet.

The prolonged effect of glucagon-like peptide 2 pretreatment on growth performance and intestinal development of weaned piglets

Background： Glucagon-like peptide 2 （GLP-2） is a potent epithelium-specific intestinal growth factor. The aim of this study was to demonstrate the prolonged effect of GLP-2 on the growth performance of weaned piglets. Forty piglets weaned at the age of 28 d with an average BW of 6.8 ＋ 0.4 kg were assigned to four treatments： （i） non- challenged control; （ii） LPS-challenged control; （iii） LPS ＋ low GLP-2; and （iv） LPS ＋ high GLP-2. Piglets in groups （i）, （ii）, and （iv） were s.c. injected with PBS supplemented with human [Gly2]GLP-21-34 at doses of 0, 2 and 10 nmol/kg BW per day for seven consecutive days. BW, gain：feed ratio （G：F）, and plasma GLP-2 levels were determined on d 0 7, and 14 after weaning. Piglets were challenged with i.p. administration of Escherichia coil lipopolysaccharide （LPS） at a dose of 100 pg/kg on d 14 to induce intestinal damage. Twenty-four hours later, intestinal tract samples were collected to assess intestinal morphology and quantify enzyme activity. Results： Plasma GLP-2 levels decreased after weaning, but in the high GLP-2 group, plasma GLP-2 was maintained on d 7 and even increased to a level higher than the preweaning level on d ]4 （P 〈 0.05）. High GLP-2 treatment significantly increased the duodenal, jejunal and ileal weight, as well as the gross weight of the small intestine （SI）, and the SI weight index （P 〈 0.05）. LPS caused villous atrophy and disrupted intestinal morphology in the duodenum, jejunum and ileum. GLP-2 also significantly increased the villus height and the villus height/crypt depth ratio （VCR） of the duodenum, jejunum, and ileum （P 〈 0.05）. Histological examination revealed that in GLP-2-treated groups, the integrity of the villus was maintained, and the villus was protected against LPS-induced damage. GLP-2 significantly increased the activity of alkaline phosphatase （AKP）, y-glutamyltranspeptidase （y-G-i-）, and pancreatic lipase in the duodenum and jejunum （P 〈 0.05）. GLP-2 treatment also significantly increased the average daily gain （ADG） and G：F of piglets at 0 to 7, 7 to 14, as well as 0 to14 d （P 〈 0.05）, resulting in a significant increase of final 8W in high GLP-2 pigs （P = 0.016）. Conclusions： Exogenous GLP-2 improved the growth of weaned piglets and protected them against LPS-induced intestinal damage. These effects may be due to the ability of GLP-2 to promote the secretion of endogenous GLP-2 to stimulate the small intestinal development.

Tauroursodeoxycholic acid(TUDCA)improves intestinal barrier function associated with TGR5-MLCK pathway and the alteration of serum metabolites and gut bacteria in weaned piglets

Background:Tauroursodeoxycholic acid(TUDCA),a hydrophilic bile acid,is the main medicinal component of bear bile and is commonly used to treat a variety of hepatobiliary diseases.Meanwhile,TUDCA has been shown to modulate the intestinal barrier function and alleviate DSS-induced colitis in mice.However,the effect of TUDCA on the intestinal barrier of weaned piglets remains largely unclear.Methods:The weaned piglets and porcine IPEC-J2 intestinal epithelial cells were used to investigate the effects of TUDCA on intestinal barrier function in weaned piglets and explore the possible underlying mechanisms.In vivo,72 healthy weaned piglets were randomly allocated into 2 groups according to their gender and body weight,and piglets were fed the basal diet with 0(control,CON)and 200 mg/kg TUDCA for 30 d,respectively.Three female and three male piglets reflecting the average bodyweight were slaughtered in each group and samples were collected.In vitro,IPEC-J2 cells were subjected to 100μmol/L TUDCA to explore the possible underlying mechanisms.Results:Our results demonstrated that dietary TUDCA supplementation significantly reduced the diarrhea incidence of weaned piglets,possibly attributing to the TUDCA-enhanced intestinal barrier function and immunity.In addition,TUDCA supplementation altered serum metabolites and the relative abundance of certain gut bacteria,which might contribute to the improved intestinal barrier function.Furthermore,the in-vitro results showed that TUDCA improved the E.coli-induced epithelial barrier impairment of IPEC-J2 cells and increased Takeda G-coupled protein receptor 5(TGR5)protein expression.However,knockdown of TGR5 and inhibition of myosin light chain kinase(MLCK)pathway abolished the TUDCA-improved epithelial barrier impairment in E.coli-treated IPEC-J2 cells,indicating the involvement of TGR5-MLCK in this process.Conclusions:These findings showed that TUDCA improved intestinal barrier function associated with TGR5-MLCK pathway and the alteration of serum metabolites and gut bacteria in weaned piglets,suggesting the potential application of TUDCA in improving gut health in piglet production.

Mechanisms Involved in the Growth Promotion of Weaned Piglets by High-level Zinc Oxide

Dietary supplementation with high lev- els of zinc oxide （ZnO） is an effective method to prevent diarrhea and promote growth in weaned pig- lets. However, the mechanisms behind these beneficial effects are not well understood. Recent advances in this field indicated that the effects of ZnO on piglet growth are achieved through multiple regulatory path- ways rather than a single pathway. This review focu- ses on recent advances in the effects of high level ZnO on： 1 ） Zn status in weaned piglets; 2 ） intestinal microbe flora regulation; 3 ） intestinal structure and function;4） ion secretion in the intestine epithelium;5） intestinal immunology; and 6） secretion of brain-in- testine peptides. ZnO appears to regulate the intestinal microflora and decreases the release of histamine to prevent diarrhea. ZnO also increases the expression of intestinal insulin-like growth factor-1 （ IGF-1 ） and the IGF-1 receptor to ameliorate intestinal injury associat- ed with weaning, and mediates secretion of brain-gut peptides to stimulate food intake, to promote the growth of piglets. Better understanding of the underly-1 ing mechanisms should inspire us to supplement the diet for weaned piglets with ZnO and investigate new approaches to prevent diarrhea and enhance growth.

Effects of Fermentation Compound Herbal Medicine on Production Performance and Immune Function of Weaned Piglets

The feed additive was composed of six Chinese Herbal（CH）（including Poria, Astragalus, Cork, Orange peel, Hawthorn and Radix）, which were fermented by Lactobacillus and used as a feed additive for piglets basal diet. Similar to group of antibiotic and herbal medicine, fermented herbal medicine was additived to basic diet in four trials with eight replications per trial, determining effect on the growth performance, biochemical and immunological indicators. Compared with the control group, the group of fermented herbal compound had higher Average Daily Gain（ADG）, higher content of immune globulin M（IgM） and immune globulin A（Ig A）（p〈0.05）. There was no significant effect on the indicators of ADG, Average Daily Feed Intake（ADFI） and diarrhea rate（p〉0.05） between groups of antibiotic and fermented herbal were observed; however, the concentrations of Total Protein（TP）, Growth Hormone（GH）, IgG, IgM and IgA significantly increased（p〈0.05） compared with the control group.

Cytoprotection and Cytothetic Effects of GLP-2 on Enterocytes from a Weaned Piglet Injured by β-conglycinin in Vitro

The experiment was conducted to study the effects and possible mechanism of GLP-2 on proliferation,metabolism and apoptosis of cultured enterocytes from a 28-d weaned piglet injured by exposure to β-conglycinin.A cell damage model was established to investigate cell proliferation, metabolism and apoptosis by exposing primary cell cultures of intestinal epithelial cells(IEC) to 1.2 and 2.4 mg/mL β-conglycinin.A 2×3 factorial experiment was then used to study the effect of different GLP-2 concentrations of(1×10-9,1×10-8 and 1×10-7mol/L),in combination with the two concentrations ofβ-conglycinin.Cells exposed to the allergenβ-conglycinin had decreased(P【0.05) MTT OD;decreased (P【0.01) protein retention and total protein content of cells;increased(P【0.01) LDH and caspase-3 activities and decreased(P【0.05) Na+,K+-ATPase activity.When GLP-2 was used in combination withβ-conglycinin,MTT OD,protein retention,total protein content and Na+,K+-ATPase activity significantly increased(P【0.05);LDH activity gradually decreased(P【0.05 or P【0.01) and Caspase-3 activity significantly decreased(P【0.01) with increasing concentrations of GLP-2.The results indicated thatβ-conglycinin had adverse effects on proliferation and integrity of IEC in vitro.GLP-2 relieved or prevented the adverse effects ofβ-conglycinin on proliferation and integrity of IEC by regulating Na+,K+- ATPase and Caspase-3 activities,and consequently affecting cell metabolism.

Effects of Supplemental Histamine on Gastric Acid Secretion, Digestive Enzyme Activities, Intestinal Microfloral of Early Weaned Piglets

Two experiments were conducted to study the effect of supplemental histamine in the diet of early-weaned piglets. In experiment A, 24 cross bred piglets with an average body weight of 6.10±0. 40 kg, weaned at the age of 28 days, were divided into four groups, fed with basal diet of low dietary copper without (control) or with supplemental histamine at 60, 120, 180μg kg-1 BW. During the two weeks and the third week after weaning, ADG(average daily gain) of piglets were increased by 15.8%(P<0. 05), 9.5%(P< 0.10) by addition of 60μg kg-1 BW histamine, but decreased by addition of 180μg kg-1BW histamine, which also increased the amount of E. coli in colon and the scour incidence. The secretion of gastric acid and pepsin were improved by both dose of supplemental histamine (60, 180μg kg-1BW) and gastric digesta pH were decreased by both. Addition of 60 μg kg-1 BW histamine improved the activities of trypsin, amylase in duodelum digesta. In experiment B, 12 cross bred piglets with an average body weight of 6. 85±0.35 kg, weaned at the age of 28 days, were divided into two groups, fed with basal diet of high dietary copper without (control) or with supplemental 60 μg kg-1 BW histamine. During the two weeks and the third week after weaning, ADG of piglets were increased by 9. 8% (P<0.05), 7. 0% (P<0. 10). The secretion of gastric acid, activities of trypsin and amylase in duodelum digesta, were also improved by addition of 60 μg kg-1BW histamine. The results showed that addition of histamine (60μg kg-1BW) in early weaned piglets could increase the secretion of gastric acid and pepsin, reduce gastric digesta pH and scour incidence, improve activities of trypsin, amylase in duodelum digesta, and the growing performance of early weaned piglets.

Estimation of endogenous protein and amino acid ileal losses in weaned piglets by regression analysis using diets with graded levels of casein

Background： Many studies have investigated endogenous loss of proteins and amino acids （AAs） at the ileal level in growing pigs. However, only a few studies have researched this subject in piglets. Knowledge regarding AA ileal digestibility in piglets would be helpful during the formulation of diets for weaning piglets, rather than just using coefficients obtained in growing pigs. Therefore, in this study, we sought to estimate endogenous protein and AA ileal losses in piglets. Furthermore, apparent and true ileal digestibility （AID and TID） of protein and AAs from casein were measured. Results： The average flow of protein was 20.8 g/kg of dry matter intake （DMI）. Basal protein loss, as estimated by regression, was 16.9 g/kg DMI. Glutamic acid, arginine, and aspartic acid （2.2, 1.4, and 1.2 g/kg DMI, respectively） were the AAs for which greater losses were seen. The AID of protein and AAs increased as the protein level in the diet increased. A higher increment in AID was observed between diets with 80 and160 g CP/kg of feed; this finding was mainly attributable to increases in glycine and arginine （46.1% and 18%, respectively）. The TID of protein was 97.8, and the TID of AAs varied from 93.9 for histidine to 100.2 for phenylalanine. Conclusions： The basal endogenous protein loss in piglets was 16.9 g/kg DMI. Endogenous protein was rich in glutamic acid, aspartic acid, and arginine, which represented 32.7% of endogenous protein loss in weaning piglets. The TID of casein was high and varied from 93.0 for histidine to 100.2 for phenylalanine.

Effects of Microbial Fermentation Feeds on Growth Performance of Weaned Piglets

[ Objective] TO study the effects of microbial fermentation feeds on growth performance of piglets, and provide the basis for their promotion and application, [ Method ] All of 60 Duroc x Landrace x Yorkshire crossbred weaned piglets, weighing 8-10 kg, were randomly housed in six groups, 10 piglets in each group. The piglets in control groups were fed with traditional daily food which contained aureomycin at 70 mg/kg . BW and concentrate feeds without antibiotics. While the piglets in experimental groups were fed with concentrate feeds without antibiotics and microbial fermentation feeds. [ Result] The results indicated that the average daily gain of experimental groups raised by 5.56%, and the feed conversion ratio reduced by 3.53% compared to control group. Moreover, the number of probiotics in the feces of experimental groups increased and pH value decreased significantly compared with the control groups （P 〈 0.05）. [ Conclusion] Microbial fermentation feeds can be used to replace antibiotics feeds, and promote healthy growth of the piglets.

Influence of Sows Farrowing Performance on Growth of 21-Day-Old Weaned Piglets and Their Correlation Research

[ Objective ] To study the influence of sows farrowing performance on the growth of 21-day-old weaned piglets and their correlation. [ Methods ] A total of 1 350 Duroc x Landrace Yorkshire piglets produced by 2-6 fetal Landrace x Yorkshire sows from 118 litters within a month were selected to be the test objects. All the newborn piglets were lactated by their parent sows. The test groups were divided according to different numbers （6 - 17） of live birth. The variance analysis were conducted on birth weight, litter weight at birth, number of 21-day-old weaning piglets, weaning weight, weaninl2g weight of litter, weaning survival rate and relative individual weight gain among different weeks. [ Results] Sows farrowing performance had significant influence on the growth performance of 21- day-old piglets. However, the influences among different traits varied, some were even on the contrary. With the increase of the number of live birth, the birth weight, weaning weight of litter and weaning survival rate showed a decline trend. And when the number of live birth was equal or more than 14, the weaning sur- vival rate dropped to below 90% （P 〈 0.01 ） ; when the number of live birth was 13, the litter weight at birth and weaning weight of litter reached the peak. What- ever the number of live birth increased or decreased, the weaning weight showed a regular decline trend. [ Conclusions] When the number of live birth changed from 11 to 13, the maximum values of the economic indicator （weaning weight of litter） and the technical specifications （weaning survival rate） were achieved.

Porcine intestinal antimicrobial peptide as an in-feed antibiotic alternative improves intestinal digestion and immunity by shaping the gut microbiota in weaned piglets

Antibiotic resistance of pathogens,which is caused by the abuse of in-feed antibiotics,threatens the sustainable development of livestock production.The present study aimed to investigate the efficiency of porcine intestinal antimicrobial peptide(PIAP)as an alternative to in-feed antibiotics in terms of growth performance,intestinal morphology,digestive enzymes and immunity,and microbiota community of the post-weaning piglets.A total of 204 piglets(Duroc×Landrace×Yorkshire,weaned at 28 d age)with a similar body weight of 7.97±1.04 kg were randomly allocated to 4 groups(51 piglets per group):(1)control group:basal diet;(2)AB group:antibiotic,basal diet+chlortetracycline(1000 mg/kg from d 1 to24;500 mg/kg from d 25 to 37);(3)P1 group:basal diet+a relatively low dose of PIAP(400 mg/kg from d 1 to 24;300 mg/kg from d 25 to 37);(4)P2 group,basal diet+a relatively high dose of PIAP(600 mg/kg from d 1 to 24;500 mg/kg from d 25 to 37).The results showed that serum indicators of hepatocyte damage and relative organ weight were not affected by these treatments(P>0.05).Compared with the AB treatment,the P1 treatment remarkably decreased jejunal crypt depth and increased jejunal and ileal villus height:crypt depth ratio(P<0.05).The values of jejunal maltase,lactase,sucrase,intestinal alkaline phosphatase,and secretory immunoglobulin A(SIg A)in the P1 group were sharply increased compared with those in the control and P2 groups(P<0.05).Compared with the control group,the P1 group decreased serum concentrations of D-lactate,diamine oxidase,and endotoxin(P<0.05),and increased the abundance of Lactobacillus reuteri(P<0.05)in the colonic feces.Furthermore,there was a positive correlation between the abundance of L.reuteri and the concentrations of maltase,lactase,sucrase,and SIg A(P<0.05).Collectively,dietary supplementation with a relatively low dose of PIAP(400 mg/kg from d 1 to 24;300 mg/kg from d 25 to 37)demonstrates beneficial effects on intestinal morphology,digestive enzymes,immunity,and permeability by shaping the gut microbiota composition in weaned piglets.This study will provide a valuable reference for using PIAP as an in-feed antibiotic alternative in swine production.