The protective role of prebiotics and probiotics on diarrhea and gut damage in the rotavirus-infected piglets

Rotavirus is one of the pathogenic causes that induce diarrhea in young animals, especially piglets, worldwide. However, nowadays, there is no specific drug available to treat the disease, and the related vaccines have no obvious efficiency in some countries. Via analyzing the pathogenesis of rotavirus, it inducing diarrhea is mainly due to disturb enteric nervous system, destroy gut mucosal integrity, induce intracellular electrolyte imbalance, and impair gut microbiota and immunity. Many studies have already proved that prebiotics and probiotics can mitigate the damage and diarrhea induced by rotavirus infection in hosts. Based on these, the current review summarizes and discusses the effects and mechanisms of prebiotics and probiotics on rotavirus-induced diarrhea in piglets. This information will highlight the basis for the swine production utilization of prebiotics and probiotics in the prevention or treatment of rotavirus infection in the future.

Effects of a Self-made Compound Chinese Herbal Medicine Additive on Growth Performance and Occurrence of Diarrhea in Weaned Piglets

In this study,the effects of compound Chinese herbal medicine on growth performance and occurrence of diarrhea in weaned piglets were investigated.A compound Chinese herbal medicine that consisted of Astragalus membranaceus,Codonopsis pilosula,Epimedium sagittatum,massa medicata fermentata,Atractylodes macrocephala,malt,Glycyrrhiza uralensis,Angelica sinensis and Crataegus pinnatifida,was crushed and then passed through a 500-mesh sieve.The obtained powder was added to the basal diet of weaned piglets.A total of 100 healthy crossbred weaned piglets,aging 26±2 days,were selected.They were randomly divided into 5groups（20 piglets/group） in according to principles of similar parity（3-5）,similar body weight and half male and half female.The piglets in the control group were fed with basal diet.For the piglets in the I,II and III groups,0.4%,0.7% and 1.0%of Chinese herbal medicine additive were added to the basal diets,respectively.The basal diet of piglets in the IV group was added with 30 mg/kg of oxytetracycline.The results showed the incidences of diarrhea in I,II and III groups were4.85%,5.14% and 5.63% lower than that of control groups（P〈0.05）.There was no significant difference in incidence of diarrhea between the control and the IV groups.

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.

Microbial Fermentation Patterns, Diarrhea Incidence, and Performance in Weaned Piglets Fed a Low Protein Diet Supplemented with Probiotics

To evaluate the effects of dietary protein levels and probiotic supplementation on microbial intestinal fermentation, diarrhea incidence, and performance in weaned piglets, 162 piglets were randomly assigned to three treatments: high-protein diet (20%), with antibiotics (HPa);high-protein diet (20%), without antibiotics (HP);and low-protein diet, without antibiotics but with probiotics (LPpb). Piglets and feed were weighed weekly to calculate the average daily gain (ADG), average daily feed intake (ADFI), and gain: feed ratio (G:F). Four piglets per treatment were killed on day 21 postweaning to collect ileal and colon digesta for measurement of short-chain fatty acids (SCFAs), branched-chain fatty acids (BCFAs), lactic acid (LA), and ammonia (AM). In the digesta collected from the ileum and colon, piglets fed the HPa diet had the lowest concentration of volatile fatty acids. Additionally, the HP diet produced the highest concentration of BCFAs, while the LPpb diet produced moreacetic, propionic, and butyric acids than the HPa and HP diets. Piglets fed the HP diet had higher incidence and severity of diarrhea than piglets fed LPpb and HPa diets, and similar values were observed between these two groups. The second week postweaning was the most critical for diarrhea measurements;during the second week, animals had higher incidence and severity of diarrhea. Piglets fed the HPa and LPpb diets had similar ADGs, while those fed the HP diet had the poorest ADG. Similar results were observed with ADFI and G:F. A low-protein diet supplemented with probiotics changed the fermentation profile, reducing toxic metabolites, promoting gut health, decreasing the incidence and severity of postweaning diarrhea, and improving the performance of piglets.

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.

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.

Efficacy of Xylooligosaccharides and Probiotics Additive to the Diets of Sows and/or Piglets on Performance,Milk Composition and Appearance of Diarrhea in Sows and Their Offspring

The present study investigated the effects of dietary supplementation of xylooligosaecharides （XOS） and probiotics （PR） on performance, milk compo- sition and diarrhea incidence of sows or their offspring. From day 90 of gestation until weaning, a total of 60 muhiparous sows were randomly assigned to three groups and given three different diets that included either the control diet （ sCON, n = 20 ）, the control diet containing 175 mg/kg XOS （ sXOS, n = 20 ） or 175 mg/kg XOS and 300 mg/kg probiotics （sXOS ＋ PR, n =20）. On day 21 of age, offspring were assigned within sow treatments to the piglet basal diet （pCON） or the piglet basal, diet supplemented with 175 mg/kg XOS （pXOS） for 28 d. Sow feed intake was recorded daily. Body weight and feed consumption of the pigs in each replicate were determined biweekly （on day 0, 14 and 28） to calculate the average daily gain （ADG） of body weight, average daily feed intake （ADFI） and the gain-to-feed ratio （ G： F）. The colostrum and milk samples were obtained on day 0 and 14 of lactation, respectively. Sow XOS or XOS ＋ PR dietary had no effect on the number of total piglets born and born alive and the piglet weight at birth. Milk composition in sow colostrum and milk were not affected by sow diet XOS or （ XOS ＋ PR） supplementation （ P 〉 0.05 ）. No maternal dietary effect was observed on the weaning weight and pre-weaning weight gains of piglets. However, there were interaction effects between sow and piglet dietary treatments on diarrhea rate and diarrhea index during day 35 -49 （P = 0.03 ） and day 21 -49 （P =0.02）. Although sow diet XOS and （XOS ＋ PR ） supplementation did not influence growth performance of weanling piglets, such as ADG and ADFI （ P 〉0.05 ）, piglets XOS supplementation significantly decreased ADFI during the whole experiment period and increased G： F during day 35 -49 and day 21 -49 （ P 〈0.05 ）. These results might suggest that combination of XOS and PR in sow diets had negative impact on the diarrhea incidence of offspring. XOS supplementation in weaned piglet diets decreased ADFI and feed conversion efficiency of weaning piglets.

Dietary supplementation of laminarin improves the reproductive performance of sows and the growth of suckling piglets

Background Maternal nutrition is essential in keeping a highly efficient production system in the pig industry.Laminarin has been shown to improve antioxidant capacity,reduce the inflammatory response,and favor the homeostasis of intestinal microbiota.However,the effect of dietary supplementation of laminarin on the reproductive performance of sows and the growth of suckling offspring remains unknown.Methods A total of 40 Landrace×Yorkshire multiparous sows on d 85 of gestation,similar in age,body weight(BW),parity and reproductive performance,were randomly divided into four dietary treatments with 10 sows per treatment,receiving a control diet(basal pregnancy or lactating diets)and a basal diet supplemented with 0.025%,0.05%and 0.10%laminarin,respectively.The experiment lasted from d 85 of gestation to d 21 of lactation.Results Laminarin supplementation linearly increased number born alive per litter(P=0.03),average daily feed intake(ADFI,P<0.01),and total milk yield of sows during the lactation of 1–21 d(P=0.02).Furthermore,maternal laminarin supplementation increased the average daily gain(ADG)of piglets while tending to reduce the culling and death rate before weaning.In addition,alterations to the composition of colostrum and milk,as well as to serum inflammatory cytokines and immunoglobulins of sows were observed.The fecal microbiota profile of sows supported the improvement of reproductive performance in sows and the growth performance in suckling offspring.Conclusions Dietary supplementation of laminarin during late pregnancy and lactation could significantly improve reproductive performance of sows and growth performance of piglets.

Effects of the kinetic pattern of dietary glucose release on nitrogen utilization, the portal amino acid profile, and nutrient transporter expression in intestinal enterocytes in piglets

Background Promoting the synchronization of glucose and amino acid release in the digestive tract of pigs could effectively improve dietary nitrogen utilization.The rational allocation of dietary starch sources and the exploration of appropriate dietary glucose release kinetics may promote the dynamic balance of dietary glucose and amino acid supplies.However,research on the effects of diets with different glucose release kinetic profiles on amino acid absorption and portal amino acid appearance in piglets is limited.This study aimed to investigate the effects of the kinetic pattern of dietary glucose release on nitrogen utilization,the portal amino acid profile,and nutrient transporter expression in intestinal enterocytes in piglets.Methods Sixty-four barrows(15.00±1.12 kg)were randomly allotted to 4 groups and fed diets formulated with starch from corn,corn/barley,corn/sorghum,or corn/cassava combinations(diets were coded A,B,C,or D respectively).Protein retention,the concentrations of portal amino acid and glucose,and the relative expression of amino acid and glucose transporter m RNAs were investigated.In vitro digestion was used to compare the dietary glucose release profiles.Results Four piglet diets with different glucose release kinetics were constructed by adjusting starch sources.The in vivo appearance dynamics of portal glucose were consistent with those of in vitro dietary glucose release kinetics.Total nitrogen excretion was reduced in the piglets in group B,while apparent nitrogen digestibility and nitrogen retention increased(P<0.05).Regardless of the time(2 h or 4 h after morning feeding),the portal total free amino acids content and contents of some individual amino acids(Thr,Glu,Gly,Ala,and Ile)of the piglets in group B were significantly higher than those in groups A,C,and D(P<0.05).Cluster analysis showed that different glucose release kinetic patterns resulted in different portal amino acid patterns in piglets,which decreased gradually with the extension of feeding time.The portal His/Phe,Pro/Glu,Leu/Val,Lys/Met,Tyr/Ile and Ala/Gly appeared higher similarity among the diet treatments.In the anterior jejunum,the glucose transporter SGLT1 was significantly positively correlated with the amino acid transporters B0AT1,EAAC1,and CAT1.Conclusions Rational allocation of starch resources could regulate dietary glucose release kinetics.In the present study,group B(corn/barley)diet exhibited a better glucose release kinetic pattern than the other groups,which could affect the portal amino acid contents and patterns by regulating the expression of amino acid transporters in the small intestine,thereby promoting nitrogen deposition in the body,and improving the utilization efficiency of dietary nitrogen.

Dietary supplementation of zinc oxide modulates intestinal functionality during the post-weaning period in clinically healthy piglets

Background To improve our understanding of host and intestinal microbiome interaction,this research investigated the effects of a high-level zinc oxide in the diet as model intervention on the intestinal microbiome and small intestinal functionality in clinically healthy post-weaning piglets.In study 1,piglets received either a high concentration of zinc(Zn)as zinc oxide(Zn O,Zn,2,690 mg/kg)or a low Zn concentration(100 mg/kg)in the diet during the post weaning period(d 14–23).The effects on the piglet's small intestinal microbiome and functionality of intestinal tissue were investigated.In study 2,the impact of timing of the dietary zinc intervention was investigated,i.e.,between d 0–14 and/or d 14–23 post weaning,and the consecutive effects on the piglet's intestinal functionality,here referring to microbiota composition and diversity and gene expression profiles.Results Differences in the small intestinal functionality were observed during the post weaning period between piglets receiving a diet with a low or high concentration Zn O content.A shift in the microbiota composition in the small intestine was observed that could be characterized as a non-pathological change,where mainly the commensals inter-changed.In the immediate post weaning period,i.e.,d 0–14,the highest number of differentially expressed genes(DEGs)in intestinal tissue were observed between animals receiving a diet with a low or high concentration Zn O content,i.e.,23 DEGs in jejunal tissue and 11 DEGs in ileal tissue.These genes are involved in biological processes related to immunity and inflammatory responses.For example,genes CD59 and REG3G were downregulated in the animals receiving a diet with a high concentration Zn O content compared to low Zn O content in both jejunum and ileum tissue.In the second study,a similar result was obtained regarding the expression of genes in intestinal tissue related to immune pathways when comparing piglets receiving a diet with a high concentration Zn O content compared to low Zn O content.Conclusions Supplementing a diet with a pharmaceutical level of Zn as Zn O for clinically healthy post weaning piglets influences various aspects intestinal functionality,in particular in the first two weeks post-weaning.The model intervention increased both the alpha diversity of the intestinal microbiome and the expression of a limited number of genes linked to the local immune system in intestinal tissue.The effects do not seem related to a direct antimicrobial effect of Zn O.

All-trans retinoic acid alleviates transmissible gastroenteritis virus-induced intestinal inflammation and barrier dysfunction in weaned piglets

Background Transmissible gastroenteritis virus(TGEV)is one of the main pathogens causing severe diarrhea of pig-lets.The pathogenesis of TGEV is closely related to intestinal inflammation.All-trans retinoic acid(ATRA)is the main active metabolite of vitamin A,which has immunomodulatory and anti-inflammatory properties.However,it is unclear whether ATRA can alleviate TGEV-induced intestinal inflammation and barrier dysfunction in piglets.This study aimed to investigate the effects of ATRA on growth performance,diarrhea,intestinal inflammation and intesti-nal barrier integrity of TGEV-challenged piglets.Methods In a 19-d study,32 weaned piglets were randomly divided into 4 treatments:Control group(basal diet),TGEV group(basal diet+TGEV challenge),TGEV+ATRA5 group(basal diet+5 mg/d ATRA+TGEV challenge)and TGEV+ATRA15 group(basal diet+15 mg/d ATRA+TGEV challenge).On d 14,piglets were orally administered TGEV or the sterile medium.Results Feeding piglets with 5 and 15 mg/d ATRA alleviated the growth inhibition and diarrhea induced by TGEV(P<0.05).Feeding piglets with 5 and 15 mg/d ATRA also inhibited the increase of serum diamine oxidase(DAO)activ-ity and the decrease of occludin and claudin-1 protein levels in jejunal mucosa induced by TGEV,and maintained intestinal barrier integrity(P<0.05).Meanwhile,5 mg/d ATRA feeding increased the sucrase activity and the expres-sions of nutrient transporter related genes(GLUT2 and SLC7A1)in jejunal mucosa of TGEV-challenged piglets(P<0.05).Furthermore,5 mg/d ATRA feeding attenuated TGEV-induced intestinal inflammatory response by inhibit-ing the release of interleukin(IL)-1β,IL-8 and tumor necrosis factor-α(TNF-α),and promoting the secretion of IL-10 and secretory immunoglobulin A(sIgA)(P<0.05).Feeding 5 mg/d ATRA also down-regulated the expressions of Toll-like receptors and RIG-I like receptors signaling pathway related genes(TLR3,TLR4,RIG-I,MyD88,TRIF and MAVS)and the phosphorylation level of nuclear factor-κB-p65(NF-κB p65),and up-regulated the inhibitor kappa B alpha(IκBα)protein level in jejunal mucosa of TGEV-challenged piglets(P<0.05).Conclusions ATRA alleviated TGEV-induced intestinal barrier damage by inhibiting inflammatory response,thus improving the growth performance and inhibiting diarrhea of piglets.The mechanism was associated with the inhibi-tion of NF-κB signaling pathway mediated by TLR3,TLR4 and RIG-I.

Composition,function,and timing:exploring the early‑life gut microbiota in piglets for probiotic interventions

Background The establishment of a robust gut microbiota in piglets during their early developmental stage holds the potential for long-term advantageous effects.However,the optimal timeframe for introducing probiotics to achieve this outcome remains uncertain.Results In the context of this investigation,we conducted a longitudinal assessment of the fecal microbiota of 63 piglets at three distinct pre-weaning time points.Simultaneously,we gathered vaginal and fecal samples from 23 sows.Employing 16S rRNA gene and metagenomic sequencing methodologies,we conducted a comprehensive analysis of the fluctuation patterns in microbial composition,functional capacity,interaction networks,and colonization resistance within the gut microbiota of piglets.As the piglets progressed in age,discernible modifications in intestinal microbial diversity,composition,and function were observed.A source-tracking analysis unveiled the pivotal role of fecal and vaginal microbiota derived from sows in populating the gut microbiota of neonatal piglets.By D21,the microbial interaction network displayed a more concise and efficient configuration,accompanied by enhanced colonization resistance relative to the other two time points.Moreover,we identified three strains of Ruminococcus sp.at D10 as potential candidates for improving piglets’weight gain during the weaning phase.Conclusions The findings of this study propose that D10 represents the most opportune juncture for the introduction of external probiotic interventions during the early stages of piglet development.This investigation augments our comprehension of the microbiota dynamics in early-life of piglets and offers valuable insights for guiding forthcoming probiotic interventions.

Screening of Traditional Chinese Medicine Prescription for Treating Damp-heat Diarrhea of Piglets

[Objective] The paper was to explore the therapeutic effect of traditional Chinese medicine on damp-heat diarrhea of piglets in summer.[Method] Three prescriptions were developed with a dozen of traditional Chinese medicines,and in vitro antibacterial test against swine standard Escherichia coli [O149：K91,K88 ac（C83907）] was conducted.Moreover,106 natural cases of diarrhea piglets caused by coinfection of damp-heat and E.coli through clinical and laboratory diagnosis were then treated.[Result] The oral liquids prepared by three traditional Chinese medicine prescriptions had certain antibacterial effect on standard pathogenic E.coli.Prescription 2 presented the strongest inhibitory effects on swine E.coli in vitro,with the MIC of 31.25 mg/m L.It had better therapeutic effect,and the effective rate reached 94.74%.[Conclusion] The prescription 2 mainly consisted of Coptis chinensis and Prunus mume might be effective in treatment of piglet diarrhea caused by damp heat and E.coli in clinic.

Effects of Bio-probiotic Betel Bokashi on Raising Pigs and Preventing Diarrhea in Young Piglets in Central Vietnam

Infection of Escherichia coli in piglets is identified as one of major problems in pig husbandry.Data were collected from different experiments conducted at farm levels and results showed that the percentage of piglets infected with E.coli was very high.E.coli infected healthy piglets were up to 48.9%and E.coli infected diarrhea piglets accounted for 88.3%.Using Betel Bokashi and antibiotics in treatment brings about different results.Out of 48 infected piglets,15 piglets were selected for three groups treatment with five each group.Results showed that 92.3%diarrhea piglets treated with Betel Bokashi recovered in 3.85 d,while 100%and 88.23%treated with antibiotics were cured in 4 d and 4.01 d,respectively.Post-treatment piglets in group 3 grew up faster than group 1 and group 2,with gains 231,218 and 212 g,respectively.

Research on Mechanism and Application of DUAN-NAI-AN on Controlling Weaned Piglet Diarrhea

[ Objective] The study aimed to explore the function mechanism of microbial ecological agent DUAN-NAI-AN on controlling weaned piglet diarrhea. E Method] DUAN-NAI-AN was given to the weaned piglets by oral administration and its effects on diarrhea rate, growth performance, in- testinal microflora, pH values of different parts of the intestine and intestinal mucosal morphology were observed. [ Result] DUAN-NAI-AN could im- prove the growth performance of weaned piglets by increasing the growth rate and phase weight gain, showing as higher livability, average daily gain and daily feed intake as well as lower diarrhea rate with 19.24% decline by contrast to the control. In addition, DUAN-NAI-AN could keep the intestinal mucosal mechanical barrier and normal digestive function by strengthening intestinal resistance and thus enhance the intestinal mucosal im- mune level. It could also decrease the proportion of potential pathogens and their toxicity effects inside the intestine to help the piglets transfer to and then maintain the dynamic balance of intestinal microflora in a very short period, and it also showed a trend of decreasing the pH value of piglet in- testinal contents. [ Conclusion] DUAN-NAI-AN is an effective microbial ecological agent for the control of weaned piglet diarrhea.

Effects of Mycotoxin from Maize on Immune Response of Vaccine for Piglets

[Objective] The aim of this study was to investigate the effects of mycotoxin from moldy maize on immune response of piglets.[Method] ELISA method was used to determine the content of Aflatoxin B1 and ochratoxin A in maize; after the piglets were fed with the moldy maize,the corresponding antibody titers in the serums of piglets were measured.[Result] Antibody levels of tested group were obvious lower than that of the control,while the histological section of immune organs also suggested that mycotoxin could significantly inhibit the immune response of piglets.[Conclusion] Mycotoxin in maize had important effects on the internal organs and immune response of piglets.

Proteomic-Level Responses of Early-Weaned Piglets to Dietary Arginine Supplementation

Dietary arginine supplementation enhances the immune status and protein synthesis in early-weaned pigs. However, the underlying mechanisms remain largely unknown. To investigate how arginine affects the expression of key proteins that regulate growth and nutrient transport of jejunum, a total of 12 healthy piglets （21 day-old, similar body weight, Landrace x Yorkshire） delivered by four sows were randomly divided into two groups. Piglets in the test group were reared with feed supplemented L-arginine at a concentration of 6.0 g/kg, while piglets in the control group were fed with feed supplemented L-alanine at a concentration of 12.3 g/kg （isonitrogenous control）. After 7 d, jejunum mucosae was collected and analyzed with the 2-D PAGE MS technology. Compared with the control pigs, arginine decreased the levels of proteins that regulate the protein syn- thesis, intermediary metabolism and tissue growth （ similar to anterior gradient 2 homolog, cyclophilin_ABHJike, hypothetical protein FLJ39502 and tetratrioopeptide repeat domain 16, similar to KIAA0156, mitechondrial ATP synthase, hydrion transporting F1 complex, beta subunit and alpha-tu- bulin ubiquitous isoform 19, prolyl 4-hydroxylase, beta subunit precursor）. In addition, arginine increased the levels of proteins that are involved in proteolysis and immune response （ PGAM1, T cell receptor beta variable 20, membrane steroid binding protein, similar to myomesin-1, and chain A, structure of pig muscle Pgk complexed with MgATP）. Therefore, arginine influences the immune response and protein synthesis mechanisms as well as improves eady weaned stress syndrome of piglets.

Effects of Feed-grade Proteinase on the Production Performance of Piglets

In this study, feed-grade proteinase was added into conventional diets of three-line crossbred （Duroc x Landrace x Large White） piglets, to investigate the effects of feed-grade proteinase on anti-diarrhea capacity, daily weight gain, feed intake and feed conversion ratio of piglets. The results showed that adding feed-grade proteinase in diets enhanced anti-diarrhea capacity of piglets and improved signifi- cantly production performance and breeding efficiency of piglets. This study provided the reference for rational utilization of feed-grade proteinase in actual production.

16S rRNA Gene-Based Analysis of Ileal Bacterial Community and Phylogeny in Nursing and Weaned Piglets

Weaning of piglets is generally considered as a stressor which changes intestinal ecosystem and leads to clinical implications. Microbiota inhabiting in small intestine （especially ileum） are assumed to promote health, but their functional properties are yet poody dascdbed. As indicated by the 16S rRNA gene sequences of ileal micrebiota in nursing piglets （at the age of 21 and 28 d） and 28-day-old weaned piglets （weaned at 21 d of age）, the microbiota were mainly comprised of gram-positive bacteria. There were 40 operational taxonomic units （OTUs） （from 171 clones） in the ileum of nursing piglets aged 21 d, 61 OTUs （from 194 clones） in the ileum of nursing piglets aged 28 d, and 56 OTUs （from 171 clones） in the ileum of weaned piglets aged 28 d. The flea of nursing piglets aged 21 d were dominantly occupied by Lactobacilli （87.7%） as well as Streptococ cus （ 3.5 % ）. Lactobacillus amy/ovorus （41.5 % ）, Lactobaci/lus sp. （ 19.3 % ）, Lactobaci/lus reuteri （ 12.3 % ）, Lactobacillus salivarius （ 9.4 % ） and L. mucosae （4.7%） were the predominant species among Lactobacil/L Similar results were obtained in the nursing piglets at 28 d of age ex- cept that Lactobaci/li decreased to 71.1% and Streptococcus increased to 21.1% significantly. Lactobacillus （52.0%） and Streptococcus （26.3%） were the two major groups in the ileum of weaned piglets aged 28 d. Lactobacillus amylovorus （31.6%） and Lactobaci/lus reuteri （ 16.4% ） was the two most important species in Lactobacillus. Therefore, Lactobacilli were predominant in the ileum of nursing and weaned piglets, and they had the highest diversity, followed by Streptococcus. The diversity of ileal microbiota was not different remarkably between the nursing piglets and the weaned piglets, but the composition changed significantly. These findings are helpful to understand ileal bacterial ecophysiology and further develop nutritional regimes to prevent or counteract complications during the weaning transition.

Adhesive Patterns of Escherichia coli F4 in Piglets of Three Breeds

Escherichia coli expressing F4 fimbriae is the major pathogenic bacteria that causes diarrhea in piglets before weaning. The adhesion of E. coli to the brush borders of the epithelial cells of piglets is the precondition leading to diarrhea, which in turn is due to the presence of the F4 receptors determined by an autosomal recessive gene on the brush borders of the epithelial cells. In order to clarify the genetic mechanism of the adhesion, an in vitro adhesion experiment was carded out for three variants of E. coli F4 （ab, ac, and ad） in 366 piglets of three pig breeds [Landrace （LR）, Large White （LW）, and Songliao Black （SB）]. The results showed that there existed significant differences （P〈0.001） in the adhesion percentage among the three breeds. Most SB piglets were nonadhesive for all the three variants, whereas most LR piglets were adhesive. Within each breed except for LR, the proportions of the three F4 variants adhering to the brush borders differed significantly. According to the patterns of the adhesion of the three F4 variants in the three breeds, it is very likely that the three F4 variants F4ab, F4ac, and F4ad have different receptors that are controlled by three different loci.