Early life administration of milk fat globule membrane promoted SCFA-producing bacteria colonization,intestinal barriers and growth performance of neonatal piglets

Milk fat globule membrane (MFGM) possesses various nutritional and biological benefits for mammals, whereas its effects on neonatal gut microbiota and barrier integrity remained unclear. This study investigated the effects of MFGM administration on microbial compositions and intestinal barrier functions of neonatal piglets. Sixteen newborn piglets were randomly allocated into a CON group or MFGM group, orally administered with saline or MFGM solution (1 g/kg body weight) respectively during the first postnatal week, and all piglets were breastfed during the whole neonatal period. The present study found that the MFGM oral administration during the first postnatal week increased the plasma immunoglobulin (Ig) G level, body weight and average daily gain of piglets (P < 0.05) on 21 d. Additionally, MFGM administration enriched fecal SCFA-producing bacteria (Ruminococaceae_UCG-002, Ruminococaceae_UCG-010, Ruminococaceae_UCG-004, Ruminococaceae_UCG-014 and [Ruminococcus]_gauvrearuii_group), SCFA concentrations (acetate, propionate and butyrate; P < 0.05) and their receptor (G-protein coupled receptor 41, GPR41). Furthermore, MFGM administration promoted intestinal villus morphology (P < 0.05) and barrier functions by upregulating genes of tight junctions (E-cadherin, claudin-1, occludin and zonula occludin 1 [ZO-1]), mucins (mucin-13 and mucin-20) and interleukin (IL)-22 (P < 0.05). Positive correlation was found between the beneficial microbes and SCFA levels pairwise with the intestinal barrier genes (P < 0.05). In conclusion, orally administrating MFGM during the first postnatal week stimulated SCFA-producing bacteria colonization and SCFA generation, enhanced intestinal barrier functions and consequently improved growth performance of neonatal piglets on 21 d. Our findings will provide new insights about MFGM intervention for microbial colonization and intestinal development of neonates during their early life.     

Source of fiber influences growth,immune responses,gut barrier function and microbiota in weaned piglets fed antibiotic-free diets

This study examined the impacts of different fiber sources on growth, immune status and gut health in weaned piglets fed antibiotic-free diets. Sixty piglets (BW = 8.18 ± 1.35 kg) were assigned to 3 dietary treatments based on BW and gender in a randomized complete block design (5 replicates/treatment and 4 piglets [2 barrows and 2 gilts]/replicate): (1) an antibiotic-free diet (control, CON); (2) CON + 6% wheat bran (WB); (3) CON + 4% sugar beet pulp (SBP). Dietary WB supplementation tended to increase ADG compared with CON from d 1 to 14 (P = 0.051) and from d 1 to 28 (P = 0.099). Supplementation of WB increased (P < 0.05) G:F compared with CON and SBP from d 1 to 14 and from d 1 to 28. Compared with CON, the addition of WB reduced (P < 0.05) diarrhea rate from d 1 to 14 and tended (P = 0.054) to reduce diarrhea rate from d 1 to 28. The addition of WB decreased (P < 0.05) serum diamine oxidase activity on d 14, and up-regulated (P < 0.05) ileal mRNA levels of occludin on d 28 when compared with CON. Piglets fed WB showed decreased (P < 0.05) serum interleukin-6 levels compared to those fed SBP and decreased (P < 0.05) ileal interleukin-8 levels compared to those fed CON and SBP on d 28. Supplementation of WB increased (P < 0.05) serum levels of immunoglobulin A (IgA), IgG and IgM compared with SBP on d 14, and increased (P < 0.05) the levels of serum IgA and ileal sIgA compared with CON and SBP on d 28. Piglets fed WB showed an enhanced (P < 0.05) α-diversity of cecal microbiota than those fed SBP, while piglets fed SBP showed reduced (P < 0.05) α-diversity of cecal microbiota than those fed CON. Compared with CON, the addition of WB elevated (P < 0.05) the abundance of Lachnospira and cecal butyric acid level. Piglets fed WB also showed increased (P < 0.05) abundances of Lachnospira and unclassified_f_Lachnospiraceae compared with those fed SBP. Collectively, the supplementation of WB to antibiotic-free diets improved performance, immune responses, gut barrier function and microbiota compared with the CON and SBP fed piglets. Therefore, supplementing weaned piglets with WB was more effective than SBP.     

Changes in progenitors and differentiated epithelial cells of neonatal piglets

This study aimed to assess the changes of small intestinal morphology,progenitors,differentiated epithelial cells,and potential mechanisms in neonatal piglets.Hematoxylin and eosin staining of samples from 36 piglets suggested that dramatic changes were observed in the jejunum crypts depth and crypt fission index of neonatal piglets(P<0.001).The number of intestinal stem cells(ISC)tended to increase(P<0.10),and a decreased number of enteroendocrine cells appeared in the jejunal crypt on d 7(P<0.05).Furthermore,the mRNA expression of jejunal chromogranin A(ChgA)was down-regulated in d 7 piglets(P<0.05).There was an up-regulation of the adult ISC marker gene of SPARC related modular calcium binding 2(Smoc2),and Wnt/b-catenin target genes on d 7(P<0.05).These results were further verified in vitro enteroid culture experiments.A mass of hollow spheroids was cultured from the fetal intestine of 0-d-old piglets(P<0.001),whereas substantial organoids with budding and branching structures were cultured from the intestine of 7-d-old piglets(P<0.001).The difference was reflected by the organoid budding efficiency,crypt domains per organoid,and the surface area of the organoid.Furthermore,spheroids on d 0 had more Ki67-positive cells and enteroendocrine cells(P<0.05)and showed a decreasing trend in the ISC and goblet cells(P<0.10).Moreover,the mRNA expression of spheroids differed markedly from that of organoids,with low expression of intestinal differentiation gene(Lysozyme;P<0.05),epithelial-specific markers(Villin,E-cadherin;P<0.05),and adult ISC markers(leucine-rich repeat-containing G protein-coupled receptor 5[Lgr5],Smoc2;P<0.001),and upregulation of fetal marker(connexin 43[Cnx43];P<0.05).The mRNA expression of relevant genes was up-regulated,and involved in Wnt/b-catenin,epidermal growth factor(EGF),Notch,and bone morphogenetic protein(BMP)signaling on d 7 organoids(P<0.05).Spheroids displayed low differentiated phenotype and high proliferation,while organoids exhibited strong differentiation potential.These results indicated that the conversion from the fetal progenitors(spheroids)to adult ISC(normal organoids)might largely be responsible for the fast development of intestinal epithelial cells in neonatal piglets.     

Different dietary protein sources influence growth performance,antioxidant capacity,immunity,fecal microbiota and metabolites in weaned piglets

The inclusion of high-quality proteins are commonly used in swine production.Our research investigated the effects of hydrolyzed wheat protein(HWP),fermented soybean meal(FSBM),and enzyme-treated soybean meal(ESBM)on growth performance,antioxidant capacity,immunity,fecal microbiota and metabolites of weaned piglets.A total of 144 piglets(weaned at 28 d)were allotted to 3 dietary treatments with 6 replicate pens per treatment and 8 piglets per pen.This study included 2 periods:d 0 to14 for phase 1 and d 15 to 28 for phase 2.Dietary treatments contained 15.90%HWP,15.80%FSBM,and 15.10%ESBM in phase 1,and 7.90%HWP,7.80%FSBM,and 7.50%ESBM in phase 2,respectively.The ADG of piglets in ESBM was increased(P<0.05)compared with HWP and FSBM during d 1e28.Compared with HWP and FSBM,ESBM increased(P<0.05)the ferric reducing ability of plasma(FRAP),and the serum level of superoxide dismutase(SOD)in piglets on d 14,as well as increased(P<0.05)the serum FRAP level in piglets on d 28.ESBM decreased(P<0.05)serum levels of DAO and IL-1b in piglets compared with HWP on d 28.ESBM enhanced(P<0.05)the relative abundance of Bacteroidetes,Oscillospiraceae and Christensenellaceae,as well as reduced the relative abundance of Clostridiaceae in the feces compared with HWP and FSBM.The PICRUSt analysis revealed that the number of gene tags related to degradation of valine,leucine and isoleucine,as well as lysine degradation in ESBM were lower(P<0.05)than that in HWP and FSBM.ESBM increased(P<0.05)the fecal butyrate level in piglets compared with FSBM,and ESBM tended to decrease(P=0.076)the fecal cadaverine level.Overall,ESBM had advantages over HWP and FSBM in improving antioxidant status,immune function,fecal bacteria and metabolites for weaned piglets.     

饲粮纤维源对仔猪生长性能、肠道发育及其消化酶活性的影响

通过检测饲粮中添加不同来源的纤维对猪生长性能、肠道发育及其消化酶活性的影响,初步探讨饲粮纤维源调控仔猪肠道健康的可能机制。试验共选取健康状况良好、体重均一[(9.26±0.17) kg]的仔猪840头(杜×长×大;32日龄),随机分为3个处理组:对照组(control group, CG),苜蓿草粉组(alfalfa meal group, AG),商品浓缩纤维组(commodity concentrated fiber, OG),每个处理4个重复,每个重复70头仔猪。预试期3 d,试验于35日龄开始,60日龄结束时屠宰取样,测量肠道重量及长度,观察小肠段绒毛形态结构并测定消化酶活性。结果发现,AG较CG显著降低仔猪的腹泻率(P<0.05),但对仔猪平均日增重、平均日采食量、料肉比均无显著影响(P>0.05);AG、OG较CG显著提高仔猪的大肠段长度和重量(P<0.05);AG较CG改善了空肠的绒毛高度及绒隐比(P>0.05),AG较OG显著提高了空肠的绒毛高度及绒隐比(P<0.05),OG较CG显著提高了回肠的绒毛高度(P<0.05);OG较CG显著降低了空肠中淀粉酶活性(P<0.05),AG较CG、OG显著提高了糜蛋白酶活性(P<0.05)。结果表明,饲粮中添加适量的苜蓿草粉可以促进仔猪的肠道发育,降低仔猪腹泻率,从而有利于仔猪生长发育。     

Dietary N-carbamylglutamate or L-arginine improves fetal intestinal amino acid profiles during intrauterine growth restriction in undernourished ewes

Our previous studies demonstrated that prenatal in utero growth restriction impairs postnatal intestinal function.Thus,improving postpartal intestinal absorption capacity and growth by manipulating the maternal diet prepartum is of importance.This work was conducted to determine whether supplementation of N-carbamylglutamate(NCG)or rumen-protected L-arginine(RP-Arg)increased fetal intestinal amino acid(AA)profiles in intrauterine growth retardation(IUGR)fetuses.On d 35 of gestation,Hu ewes(n=32)carrying twin fetuses were randomized into 4 groups(8 ewes and 16 fetuses in each group),where diets were as follows:100%of nutrient requirements recommended by National Research Council(NRC,2007)(CON);50%of nutrient requirements recommended by NRC(2007)(RES);RES+RPArg(20 g/d),(RES+ARG);and RES+NCG(5 g/d),(RES+NCG).On d 110 of gestation,both fetal and maternal tissues were collected and weighed.Compared with RES,solute carrier family 1,member 5(SLC1A5)was upregulated(P<0.05)within fetal jejunum,duodenum and ileum when supplementing NCG and RP-Arg.Relative to RES,RP-Arg or NCG supplementation to RES resulted in upregulation(P<0.05)of peptide transporter 1 protein abundance within the fetal ileum.NCG or RP-Arg supplementation to RES also upregulated phosphorylated mechanistic target of rapamycin(pmTOR)-to-mTOR ratio in the fetal ileum induced by IUGR(P<0.05).As a result,during IUGR,supplementation of Arg or NCG affected intestinal AA profiles in the fetus in part through controlling mTOR signal transduction as well as AA and peptide transport.Future studies should be conducted to understand the role(if any)of the placenta on the improvement of growth and AA profiles independent of the fetal intestine.This would help demonstrate the relative contribution of intestinal uptake in fetal life.     

Serum biochemical parameters and amino acids metabolism are altered in piglets by early-weaning and proline and putrescine supplementations

The study was to investigate the effect of early-weaning stress and proline (Pro) and putrescine (Put) supplementations on serum biochemical parameters and amino acids (AA) metabolism in suckling and post-weaning pigs. Blood and small intestinal mucosa were harvested from suckling piglets at 1, 7, 14, and 21 d of age and piglets on d 1, 3, 5, and 7 after weaning at 14 d of age, as well as from piglets received oral administration of Pro and Put from 1 to 14 d old. In suckling piglets, the serum glucose, albumin and total cholesterol levels were increased (P < 0.05) with increasing age, whereas the serum globulin, urea nitrogen (BUN), alkaline phosphatase (ALP) and aspartate aminotransferase (AST) levels were lowered (P < 0.05). The concentrations of most serum AA and the AA transporters related gene expressions were highest in 7-d-old piglets (P < 0.05), whereas the phosphorylation status of the mammalian target of the rapamycin (mTOR) signaling pathway in the small intestine increased in piglets from 1 to 21 d old (P < 0.05). Weaning at 14 d old increased (P < 0.05) the BUN and triglycerides levels in serum, as well as jejunal solute carrier family 7 member 6 (SLC7A6), ileal SLC36A1 and SLC1A1 mRNA abundances at d 1 or 3 post-weaning. Weaning also inhibited (P < 0.05) the phosphorylation levels of mTOR and its downstream ribosomal protein S6 kinase 1 (S6K1) and 4E-binding protein-1 (4EBP1) in the small intestine of weanling pigs. Oral administration of Put and Pro decreased (P < 0.05) serum ALP levels and increased (P < 0.05) intestinal SLC36A1 and SLC1A1 mRNA abundances and mTOR pathway phosphorylation levels in post-weaning pigs. Pro but not Put treatment enhanced (P < 0.05) serum Pro, arginine (Arg) and glutamine (Gln) concentrations of weaning-pigs. These findings indicated that early-weaning dramatically altered the biochemical blood metabolites, AA profile and intestinal mTOR pathway activity, and Pro and Put supplementations improved the AA metabolism and transportation as well as activated the intestinal mTOR pathway in weanling-pigs. Our study has an important implication for the broad application of Pro and Put in the weaning transition of piglets.     

Dietary dihydroartemisinin supplementation alleviates intestinal inflammatory injury through TLR4/NOD/NF-κB signaling pathway in weaned piglets with intrauterine growth retardation

The aim of present study was to evaluate whether diets supplemented with dihydroartemisinin (DHA) could alleviate intestinal inflammatory injury in weaned piglets with intrauterine growth retardation (IUGR). Twelve normal birth weight (NBW) piglets and 12 piglets with IUGR were fed a basal diet (NBW-CON and IUCR-CON groups), and another 12 piglets with IUGR were fed the basal diet supplemented with DHA at 80 mg/kg (IUGR-DHA group) from 21 to 49 d of age. At 49 d of age, 8 piglets with similar body weight in each group were sacrificed. The jejunal and ileal samples were collected for further analysis. The results showed that IUGR impaired intestinal morphology, increased intestinal inflammatory response, raised enterocyte apoptosis and reduced enterocyte proliferation and activated transmembrane toll-like receptor 4 (TLR4)/nucleotide-binding and oligomerization domain (NOD)/nuclear factor-κB (NF-κB) signaling pathway. Dihydroartemisinin inclusion ameliorated intestinal morphology, indicated by increased villus height, villus height-to-crypt depth ratio, villus surface area and decreased villus width of piglets with IUGR (P < 0.05). Compared with NBW piglets, IUGR piglets supplemented with DHA exhibited higher apoptosis index and caspase-3 expression, and lower proliferation index and proliferating cell nuclear antigen expression in the intestine (P < 0.05). Dihydroartemisinin supplementation attenuated the intestinal inflammation of piglets with IUGR, indicated by increased concentrations of intestinal inflammatory cytokines and lipopolysaccharides (P < 0.05). In addition, DHA supplementation down-regulated the related mRNA expressions of TLR4/NOD/NF-κB signaling pathway and upregulated mRNA expressions of negative regulators of TLR4 and NOD signaling pathway in the intestine of piglets with IUGR (P < 0.05). Piglets in the IUGR-DHA group showed lower protein expressions of TLR4, phosphorylated NF-κB (pNF-κB) inhibitor α, nuclear pNF-κB, and higher protein expression of cytoplasmic pNF-κB in the intestine than those in the IUGR-CON group (P < 0.05). In conclusion, DHA supplementation could improve intestinal morphology, regulate enterocyte proliferation and apoptosis, and alleviate intestinal inflammation through TLR4/NOD/NF-κB signaling pathway in weaned piglets with IUGR.     

Dietary ferulic acid and vanillic acid on inflammation,gut barrier function and growth performance in lipopolysaccharide-challenged piglets

Ferulic acid(FA) and vanillic acid(VA) are considered as major phenolic metabolites of cyanidin 3-glucoside, a polyphenol that widely exists in plants that possess a protective effect against oxidative stress and inflammation in our previous study. This study aimed to investigate the effect of FA and VA on inflammation, gut barrier function, and growth performance in a weaned piglet model challenged with lipopolysaccharide(LPS). Thirty-six piglets(PIC 337 × C48, 28 d of age) were randomly alloca...     

Organic acid blends improve intestinal integrity,modulate short-chain fatty acids profiles and alter microbiota of broilers under necrotic enteritis challenge

Controlling enteric diseases of broilers is crucial.Among many additives,organic acids(OA)and their blends are gaining attention to combat diseases in the post-antibiotic era.The current study evaluated the potentials of short-chain fatty acids(SCFA)and medium-chain fatty acids(MCFA)blends and/or phenolic compounds on intestinal integrity,intestinal pH,caecal microbiota,and caecal SCFA profiles of broilers under necrotic enteritis(NE)challenge.The additives used were:(A)a blend of SCFA,MCFA,and a phenolic compound(SMP),(B)a blend of free and buffered SCFA with MCFA(SMF),and(C)a blend of free and buffered SCFA with a high concentration of MCFA(SHM).A total of 1,404 male parental chicks of Ross 308 broilers were randomly allocated to 78 floor pens on hatching day with 6 treatments replicated 13 times with 18 birds per pen.The treatments were:UCC,unchallenged control;CHC,challenged control;BAC,challenged group plus zinc bacitracin;SMP,challenged group plus additive SMP;SMF,challenged group plus additive SMF;SHM,challenged group plus additive SHM.Birds were challenged with field-strain Eimeria spp.on d 9 and Clostridium perfringens on d 14.Birds challenged with NE increased fluorescein isothiocyanate dextran(FITC-d)concentration in serum,reduced acetate and butyrate concentrations,and increased Bacteroides and C.perfringens load in the caeca(P<0.05).Birds fed additives decreased FITC-d from gut to serum,reduced Bacteroides(d 16,P<0.05)and numerically reduced C.perfringens load compared to CHC group.Birds fed additive SHM had higher concentrations of acetate and butyrate(d 21,P<0.05)than CHC group but were not different from SMP and SMF groups.All the additives exhibited similar intestinal protection against NE compared to the BAC group indicated by FITC-d concentration in serum,acetate,propionate and butyrate concentrations in the caeca,and caecal bacterial loads except for the C.perfringens(P>0.05).The SMP group had a higher load compared to BAC(P<0.05).These findings suggest the promising effects of OA blends as alternatives to BAC to ameliorate the impact of NE challenge of broilers as indicated by improved intestinal health.     

Gut microbiota absence and transplantation affect growth and intestinal functions: An investigation in a germ-free pig model

This study was conducted to investigate host–microbiota interactions and explore the effects of maternal gut microbiota transplantation on the growth and intestinal functions of newborns in a germ-free (GF) pig model. Twelve hysterectomy-derived GF Bama piglets were reared in 6 sterile isolators. Among them, 6 were considered as the GF group, and the other 6 were orally inoculated with healthy sow fecal suspension as fecal microbiota transplanted (FMT) group. Another 6 piglets from natural birth were regarded as the conventional (CV) group. The GF and FMT groups were hand-fed with Co60-γ-irradiated sterile milk powder, while the CV group was reared by lactating Bama sows. All groups were fed for 21 days. Then, all piglets and then were switched to sterile feed for another 21 days. Results showed that the growth performance, nutrient digestibility, and concentrations of short-chain fatty acids in the GF group decreased (P < 0.05). Meanwhile, the serum urea nitrogen concentration and digesta pH values in the GF group increased compared with those in the FMT and CV groups (P < 0.05). Compared with the CV group, the GF group demonstrated upregulation in the mRNA expression levels of intestinal barrier function-related genes in the small intestine (P < 0.05). In addition, the mRNA abundances of intestinal development and absorption-related genes in the small intestine and colon were higher in the GF group than in the CV and FMT groups (P < 0.05). The FMT group exhibited greater growth performance, lipase activity, and nutrient digestibility (P < 0.05), higher mRNA expression levels of intestinal development and barrier-related genes in the small intestine (P < 0.05), and lower mRNA abundances of pro-inflammatory factor in the colon and jejunum (P < 0.05) than the CV group. In conclusion, the absence of gut microbes impaired the growth and nutrient digestibility, and healthy sow gut microbiota transplantation increased the growth and nutrient digestibility and improved the intestinal development and barrier function of newborn piglets, indicating the importance of intestinal microbes for intestinal development and functions.     

Effects of graded levels of xylo-oligosaccharides on growth performance,serum parameters,intestinal morphology,and intestinal barrier function in weaned piglets

The objective of this study was to investigate the effects of xylo-oligosaccharides (XOSs) supplementation on growth performance, serum parameters, small intestinal morphology, intestinal mucosal integrity, and immune function in weaned piglets. A total of 240 weaned piglets with an average body weight (BW) of 8.82 ± 0.05 kg (28 d of age) were assigned randomly to four dietary treatments in a 28-d trial, including a control (CON) diet and three diets with XOS supplementation at the concentration of 100 (XOS100), 500 (XOS500), and 1,000 (XOS1000) mg/kg. There were four replicates per treatment with 15 pigs per pen. From day 1 to 14, there were no differences (P > 0.05) in average daily gain (ADG), average daily feed intake, and gain to feed ratio (G:F) during the different treatments. The different doses of XOSs showed a quadratic effect on BW on day 28, ADG, and G:F on day 1 to 28 of piglets (P < 0.05). From day 15 to 28, ADG of pigs fed the XOS500 diet was higher (P < 0.05) than pigs fed the CON diet. During the overall period (day 1 to 28), pigs fed the XOS500 diet had a higher BW, ADG, and G:F than pigs fed the CON diet (P < 0.05). In addition, compared with the CON group, the XOS500 group had significantly higher serum total antioxidant capacity, total superoxide dismutase and catalase levels, and lower malondialdehyde levels on days 14 and 28 (P < 0.05). The serum immunoglobulin G (IgG) concentration in the XOS500 group was also significantly higher compared with the CON group on days 14 and 28 (P < 0.05). However, serum immunoglobulin A and immunoglobulin M were not affected by the dietary treatments. Supplementation of XOS500 to the feed significantly increased the villus height (VH) and VH to crypt depth ratio in the jejunum and ileum in comparison with the CON and XOS1000 groups. Moreover, the XOS500 group significantly elevated the expression levels of occludin and zonula occludens protein-1 in the ileum compared with the CON group. The ileal interleukin (IL)-1β, IL-8, and interferon (IFN)-γ mRNA expression levels in the XOS100 and XOS500 groups were markedly lower than in the CON group. In contrast, the ileal IL-10 mRNA expression levels were remarkably higher in the XOS500 than in the CON group. In conclusion, XOSs have a beneficial effect on growth performance by improving serum antioxidant defense system, serum IgG, small intestinal structure, and intestinal barrier function in weaned piglets.     

Spermine protects intestinal barrier integrity through ras-related C3 botulinum toxin substrate 1/phospholipase C-γ1 signaling pathway in piglets

Weaning stress can cause tight junctions damage and intestinal permeability enhancement, which leads to intestinal imbalance and growth retardation, thereby causing damage to piglet growth and development. Spermine can reduce stress. However, the mechanism of spermine modulating the intestinal integrity in pigs remains largely unknown. This study aims to examine whether spermine protects the intestinal barrier integrity of piglets through ras-related C3 botulinum toxin substrate 1 (Rac1)/phospholipase C-γ1 (PLC-γ1) signaling pathway. In vivo, 80 piglets were categorised into 4 control groups and 4 spermine groups (10 piglets per group). The piglets were fed with normal saline or spermine at 0.4 mmol/kg BW for 7 h and 3, 6 and 9 d. In vitro, we investigated whether spermine protects the intestinal barrier after a tumor necrosis factor α (TNF-α) challenge through Rac1/PLC-γ1 signaling pathway. The in vivo study found that spermine supplementation increased tight junction protein mRNA levels and Rac1/PLC-γ1 signaling pathway gene expression in the jejunum of piglets. The serum D-lactate content was significantly decreased after spermine supplementation (P < 0.05). The in vitro study found that 0.1 μmol/L spermine increased the levels of tight junction protein expression, Rac1/PLC-γ1 signaling pathway and transepithelial electrical resistance, and decreased paracellular permeability (P < 0.05). Further experiments demonstrated that spermine supplementation enhanced the levels of tight junction protein expression, Rac1/PLC-γ1 signaling pathway and transepithelial electrical resistance, and decreased paracellular permeability compared with the NSC-23766 and U73122 treatment with spermine after TNF-α challenge (P < 0.05). Collectively, spermine protects intestinal barrier integrity through Rac1/PLC-γ1 signaling pathway in piglets.     

Dietary high protein-induced diarrhea and intestinal inflammation by activation of NF-κB signaling in piglets

The present study aimed to investigate whether inflammation-associated responses in piglets are induced by high protein (HP) through activating nuclear factor kappa B (NF-κB) signaling. Sixteen piglets (35 d of age, Duroc × [Landrace × Yorkshire], weaned at d 21, initial BW = 9.70 ± 0.11 kg) were allocated to 18% and 26% CP (HP group) at random, comprising 8 replicate pens per treatment. The piglets were slaughtered to collect intestinal tissues when apparent, persistent, and stable diarrhea syndromes happened (on d 12). No significant differences were observed in their growth performance (P > 0.05), but reduction by 19.11%, 25.31%, 23.64% of ADFI, ADG, and G:F, respectively was detected in the HP group. The HP group had greater (P = 0.002) diarrhea rates. Furthermore, dietary HP had lower ileal villus height (VH; P = 0.048), ratio of villus height to crypt depth (VH/CD ratio; P = 0.016), and colonic CD (P = 0.034), as well as had the trend (P = 0.075) to reduce the ileal villus absorptive area. Moreover, HP diets significantly elevated the goblet cell numbers in the ileal villi (P = 0.016) and colonic crypts (P < 0.001) and up-regulated (P = 0.012) the mRNA expression of mucin2 (Muc2) in the ileum. In addition, HP diets increased the myeloperoxidase concentration in the ileum (P = 0.002) and colon (P = 0.007) of piglets. Dietary HP significantly down-regulated the mRNA expression of tumor necrosis factor-α (TNF-α; P < 0.001) in the ileum, induced nitric oxide synthase (iNOS; P = 0.040) and interleukin-22 (IL-22; P = 0.008) in the colon, and inclined to down-regulate interleukin-1β (IL-1β; P = 0.076) expression in the colon. The relative protein abundance of Galectin-3 (P = 0.046) in the colon and the ratio of phosphorylation NF-κB to NF-κB (p–NF–κB/NF-κB ratio) in the ileum of HP piglets were also greater (P = 0.038). These results suggest that dietary HP may cause diarrhea in piglets by activating NF-κB signaling induced intestinal inflammation.     

Dietary nano-selenium alleviated intestinal damage of juvenile grass carp(Ctenopharyngodon idella)induced by high-fat diet:Insight from intestinal morphology,tight junction,inflammation,anti-oxidization and intestinal microbiota

In recent years,high-fat diet(HFD)has been widely applied in aquaculture,which reduces the intestinal health of cultured fish.The current study evaluated the protective effects of nano-selenium(nano-Se)on intestinal health of juvenile grass carp(Ctenopharyngodon idella)fed with HFD.A total of 135 experimental fish were fed with a regular diet(Con),a HFD(HFD)and a HFD containing nano-Se at 0.6 mg/kg(HSe)for 10 weeks.The results showed that dietary nano-Se significantly improved the survival rate and feed efficiency which were reduced by HFD in juvenile grass carp(P<0.05).Also,nano-Se(0.6 mg/kg)supplement alleviated intestinal damage caused by the HFD,thus maintaining the integrity of the intestine.Moreover,it significantly up-regulated the expression of genes related to tight junction(ZO-1,claudin-3 and occludin),anti-oxidization(GPx4a and GPx4b),and the protein of ZO-1 in the intestine of juvenile grass carp,which were depressed by the HFD(P<0.05).Furthermore,nano-Se supplementation significantly suppressed the expressions of genes related to the inflammation,including inflammatory cytokines(IL-8,IL-1β,IFN-γ,TNF-αand IL-6),signaling molecules(TLR4,p38 MAPK and NF-kB p65),and protein expression of NF-kB p65 and TNF-αin the intestine of juvenile grass carp which were induced by the HFD(P<0.05).Besides,dietary nano-Se normalized the intestinal microbiota imbalance of juvenile grass carp caused by the HFD through increasing the abundance of the beneficial bacteria,e.g.,Fusobacteria.Finally,dietary nano-Se increased the production of short chain fatty acids(SCFA)in the intestine,especially for butyric acid and caproic acid,which were negatively related to the increase of intestinal permeability and inflammation.In summary,supply of nano-Se(0.6 mg/kg)in HFD could effectively alleviate intestinal injury of juvenile grass carp by improving intestinal barrier function and reducing intestinal inflammation and oxidative stress.These positive effects may be due to the regulation of nano-Se on intestinal microbiota and the subsequently increased beneficial SCFA levels.     

Dietary inclusion of multispecies probiotics to reduce the severity of post-weaning diarrhea caused by Escherichia coli F18+ in pigs

This study was aimed to determine the efficacy of multispecies probiotics in reducing the severity of post-weaning diarrhea caused by enterotoxigenic Escherichia coli (ETEC) F18⁺ on newly weaned pigs. Thirty-two pigs (16 barrows and 16 gilts, BW = 6.99 ± 0.33 kg) at 21 d of age were individually allotted in a randomized complete block design with 2 × 2 factorial arrangement of treatments. Pigs were selected from sows not infected previously and not vaccinated against ETEC. Pigs were fed experimental diets for 25 d based on 10 d phase 1 and 15 d phase 2. The factors were ETEC challenge (oral inoculation of saline solution or E. coli F18⁺ at 2 × 10⁹ CFU) and probiotics (none or multispecies probiotics 0.15% and 0.10% for phase 1 and 2, respectively). Body weight and feed intake were measured on d 5, 9, 13, 19, and 25. Fecal scores were measured daily. Blood samples were taken on d 19 and 24. On d 25, all pigs were euthanized to obtain samples of digesta, intestinal tissues, and spleen. The tumor necrosis factor alpha (TNFα), malondialdehyde (MDA), peptide YY (PYY), and neuropeptide Y (NPY) were measured in serum and intestinal tissue. Data were analyzed using the MIXED procedure of SAS. The fecal score of pigs was increased (P < 0.05) by ETEC challenge at the post–challenge period. The ETEC challenge decreased (P < 0.05) jejunal villus height and crypt depth, tended to increase (P = 0.056) jejunal TNFα, increased (P < 0.05) ileal crypt depth, and decreased (P < 0.05) serum NPY. The probiotics decreased (P < 0.05) serum TNFα, tended to reduce (P = 0.064) jejunal MDA, tended to increase (P = 0.092) serum PYY, and increased (P < 0.05) jejunal villus height, and especially villus height-to-crypt depth ratio in challenged pigs. Growth performance of pigs were not affected by ETEC challenge, whereas the probiotics increased (P < 0.05) ADG and ADFI and tended to increase (P = 0.069) G:F ratio. In conclusion, ETEC F18⁺ challenge caused diarrhea, intestinal inflammation and morphological damages without affecting the growth performance. The multispecies probiotics enhanced growth performance by reducing intestinal inflammation, oxidative stress, morphological damages.     

Natural capsicum extract replacing chlortetracycline enhances performance via improving digestive enzyme activities,antioxidant capacity,anti-inflammatory function,and gut health in weaned pigs

The objective of this study was to investigate the effects of natural capsicum extract (NCE, containing 2% natural capsaicin, the rest is carrier) replacing chlortetracycline (CTC) on performance, digestive enzyme activities, antioxidant capacity, inflammatory cytokines, and gut health in weaned pigs. A total of 108 weaned pigs (Duroc × [Landrace × Yorkshire], initial body weight = 8.68 ± 1.34 kg; weaned on d 28) were randomly allotted into 3 treatments with 6 replicate pens per treatment (3 barrows and 3 gilts per pen). The treatments include a corn-soybean meal basal diet as a control group (CON), a CTC group (basal diet + CTC at 75 mg/kg), and a NCE group (basal diet + NEC at 80 mg/kg). Compared with CON and CTC, NCE had increased (P < 0.05) average daily gain in phase 2 (d 15 to 28) and overall (d 1 to 28), and higher (P < 0.05) apparent total tract digestibility of gross energy, dry matter, crude protein, and organic matter in phase 1 (d 1 to 14). These pigs also had increased (P < 0.05) pancrelipase activity in pancreas, α-amylase, lipase and protease activities in the jejunal mucosa, and lipase activity in the ileal mucosa on d 28. Moreover, NCE had increased (P < 0.05) the contents of growth hormone, β-endorphin, 5-hydroxytryptamine, total antioxidant capacity, total superoxide dismutase, catalase, and IL-10, as well as decreased (P < 0.05) contents of malondialdehyde, tumor nuclear factor-α, interferon-γ, and interleukin-6 in serum on d 28 compared with CON and CTC. NCE showed higher (P < 0.05) propionic acid, butyric acid and total volatile fatty acids (VFA) contents, and increased (P < 0.05) relative abundance of Faecalibacterium in colon, as well as higher (P < 0.05) propionic acid and total volatile fatty acids in cecum on d 28 compared with CON. In conclusion, NCE replacing CTC could enhance performance via improving digestive enzyme activities, antioxidant capacity, anti-inflammatory function, gut VFA composition and microbiota community in weaned pigs, and it could be used as a potential target for the development of feed additives.     

苜蓿草粉和黄酮对断奶仔猪结肠微生物区系的影响

本试验旨在研究苜蓿草粉和苜蓿黄酮对断奶仔猪结肠微生物区系的影响。选取平均体重为(8.1±0.5) kg和胎次相近的(35±1)日龄"杜×长×大"三元杂交断奶仔猪120头,随机分成5组(每组3个重复,每个重复8头猪):对照组饲喂基础饲粮,试验组分别添加1(Ⅰ组)、2(Ⅱ组)、4(Ⅲ组)g·kg^-1的苜蓿黄酮和50 g·kg^-1的苜蓿草粉(Ⅳ组);预试验期3 d,正式试验期32 d。试验采集的结肠内容物,提取总DNA后在Illumina Miseq平台进行测序。结果表明:1)5个组共产生了484个操作分类单元(operational taxonomic units,OTUs),其中共享327个OTU,占总OTU数量的67.56%,其中Ⅰ组的OTU数量最高。2)物种丰富度ACE指数(community richness the ACE estimator,ACE)呈先上升再下降再上升趋势,其中Ⅰ组显著高于对照组(P<0.05);物种丰富度Chao指数(community richness the Chao estimator,Chao)呈先上升再下降再上升趋势,其中Ⅰ组显著高于对照组(P<0.05)。与对照组相比,Ⅳ组的Sobs(the observed richness,Sobs)、ACE、Chao指数均无显著差异(P>0.05)。各组之间的Shannon指数和Simpson指数均无显著差异(P>0.05)。3)在门水平上,各组间厚壁菌门和拟杆菌门的相对丰度均无显著差异(P>0.05)。在属水平上,各组间梭菌属相对丰度有升高的趋势(P>0.05),其中Ⅰ组和Ⅲ组梭菌属相对丰度显著高于对照组(P<0.05)。与对照组相比,Ⅱ组粪球菌属相对丰度显著提高(P<0.05)。各组间真细菌属相对丰度有升高的趋势(P>0.05),其中Ⅱ组真细菌属相对丰度显著高于对照组(P<0.05)。各组间Anaerotruncus相对丰度有显著差异(P<0.05),其中Ⅱ组和Ⅳ组显著高于对照组(P<0.05);各组间NC2004相对丰度有差异(P>0.05),其中Ⅲ组NC2004相对丰度显著提高(P<0.05)。各组间UCG-014、Erysipelotrichaceae和胃球菌属相对丰度有显著差异(P<0.05)。由此可见,饲粮中添加苜蓿草粉和苜蓿黄酮能够改变结肠微生物细菌组成和结构,进而影响营养物质的消化代谢。     

Low-protein diets supplemented with glutamic acid or aspartic acid ameliorate intestinal damage in weaned piglets challenged with hydrogen peroxide

Glutamic acid (Glu) and aspartic acid (Asp) are acidic amino acids with regulatory roles in nutrition, energy metabolism, and oxidative stress. This study aimed to evaluate the effects of low-protein diets supplemented with Glu and Asp on the intestinal barrier function and energy metabolism in weaned piglets challenged with hydrogen peroxide (H₂O₂). Forty piglets were randomly divided into 5 groups: NC, PC, PGA, PG, and PA (n = 8 for each group). Pigs in the NC and PC groups were fed a low-protein diet, while pigs in the PGA, PG, or PA groups were fed the low-protein diet supplemented with 2.0% Glu +1.0% Asp, 2.0% Glu, or 1.0% Asp, respectively. On day 8 and 11, pigs in the NC group were intraperitoneally injected with saline (1 mL/kg BW), while pigs in the other groups were intraperitoneally administered 10% H₂O₂ (1 mL/kg BW). On day 14, all pigs were sacrificed to collect jejunum and ileum following the blood sample collection in the morning. Notably, low-protein diets supplemented with Glu or Asp ameliorated the intestinal oxidative stress response in H₂O₂-challenged piglets by decreasing intestinal expression of genes (P < 0.05) (e.g., manganese superoxide dismutase [MnSOD], glutathione peroxidase [Gpx]-1, and Gpx-4) encoding oxidative stress-associated proteins, reducing the serum concentration of diamine oxidase (P < 0.05), and inhibiting apoptosis of the intestinal epithelium. Glu and Asp supplementation attenuated the upregulated expression of energy metabolism-associated genes (such as hexokinase and carnitine palmitoyltransferase-1) and the H₂O₂-induced activation of acetyl-coenzyme A carboxylase (ACC) in the jejunum and adenosine monophosphate-activated protein kinase–acetyl-ACC signaling in the ileum. Dietary Glu and Asp also ameliorated intestinal barrier damage as indicated by restored intestinal histology and morphology. In conclusion, low-protein diets supplemented with Glu and Asp protected against oxidative stress-induced intestinal dysfunction in piglets, suggesting that this approach could be used as a nutritional regulatory protectant against oxidative stress.     

Potential of a mixture of eugenol and garlic tincture to improve performance and intestinal health in broilers under necrotic enteritis challenge

Plant extracts(PE)are gaining increased attention as potential alternatives to in-feed antimicrobials(AM)due to their known antimicrobial activities.This study was conducted to examine the potential of PE,a microencapsulated product composed of eugenol and garlic tincture as an alternative to AM-agent on performance and intestinal health in broilers under necrotic enteritis(NE)challenge.A total of 960 dayold mixed-sex Cobb 500 chicks were randomly distributed to 48-floor pens with 6 treatments replicated 8 times with 20 birds each.The 6 treatments were as follows:UC,unchallenged control;CC,challenged control;PE,challenged group plus PE;AM,challenged group plus AM;FAP,challenged group plus a full dose of AM with PE;HAP,challenged group plus a half dose of AM with PE in starter,grower and finisher phases.Birds in the challenged groups were inoculated with Eimeria spp.on d 9 and Clostridium perfringens on d 14.The body weight gain(BWG),feed intake(FI),feed conversion ratio(FCR),and livability of birds were compromised,and intestinal lesions and mortality were increased(P<0.05)by NE challenge,illustrating a successful clinical NE challenge.Birds fed AM had higher BWG and FI,and lower FCR,mortality,and intestinal lesions compared to the CC group(P<0.05).Birds fed PE had improved FCR(P<0.05)and livability(5.8%)in an overall period compared to the CC group.On d 16,PE supplementation reduced ileal lesion scores in only male birds(P<0.05).Birds fed PE had decreased Eimeria maxima and Eimeria acervulina oocyst counts in caecal content(P<0.05).Birds fed PE had decreased Eimeria brunetti and total oocyst counts in caecal content,and E.acervulina oocyst counts in ileal content in only female birds(P<0.05).On d 35,PE supplementation reduced variation of BW in both male and female birds and increased yellowness(b*value,14.4%)in the thigh.These findings suggest the potential of PE supplementation in diets to improve the performance and intestinal health of birds under clinical NE as indicated by improved FCR,livability,uniformity,reduced ileal lesions,oocyst counts and increased skin yellowness.However,the protective effect of PE may not be apparent in the presence of AM in the feed.