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.

Yeast hydrolysate attenuates lipopolysaccharide-induced inflammatory responses and intestinal barrier damage in weaned piglets

Background Intestinal inflammation is the main risk factor causing intestinal barrier dysfunction and lipopolysaccharide(LPS)can trigger inflammatory responses in various eukaryotic species.Yeast hydrolysate(YH)possesses multibiological effects and is received remarkable attention as a functional ingredient for improving growth performance and promoting health in animals.However,there is still inconclusive on the protective effects of dietary YH supplementation on intestinal barrier of piglets.This study was conducted to investigate the attenuate effects of YH supplementation on inflammatory responses and intestinal barrier injury in piglets challenged with LPS.Methods Twenty-four piglets(with an average body weight of 7.42±0.34 kg)weaned at 21 days of age were randomly assigned to one of two dietary treatments(12 replications with one pig per pen):a basal diet or a basal diet containing YH(5 g/kg).On the 22nd d,6 piglets in each treatment were intraperitoneally injected with LPS at 150μg/kg BW,and the others were injected with the same amount of sterile normal saline.Four hours later,blood samples of each piglet were collected and then piglets were euthanized.Results Dietary YH supplementation increased average daily feed intake and average daily gain(P<0.01),decreased the ratio of feed intake to gain of piglets(P sponse,evidenced by the increase o=0.048).Lipopolysaccharide(LPS)injection induced systemic inflammatory ref serum concentrations of haptoglobin(HP),adrenocorticotropic hormone(ACTH),cortisol,and interleukin-1β(IL-1β).Furthermore,LPS challenge resulted in inflammatory intestinal damage,by up-regulation of the protein or mRNA abundances of tumor necrosis factor-α(TNF-α),IL-1β,toll-like receptors 4(TLR4)and phosphor-nuclear factor-κB-p65(p-NFκB-p65)(P<0.01),and down-regulation of the jejunal villus height,the protein and mRNA abundances of zonula occludens-1(ZO-1)and occludin(OCC;P<0.05)in jejunal mucosa.Dietary YH supplementation decreased the impaired effects of ACTH,cortisol,HP,IL-1βand diamine oxidase in serum(P<0.05).Moreover,YH supplementation also up-regulated the jejunal villus height,protein and mRNA abundances of ZO-1 and OCC(P<0.05),down-regulated the mRNA expressions of TNF-αand IL-1βand the protein abundances of TNF-α,IL-1β,TLR4 and p-NFκB-p65 in jejunal mucosa in LPS-challenged pigs(P<0.01).Conclusion Yeast hydrolysate could attenuate inflammatory response and intestinal barrier injury in weaned piglets challenged with LPS,which was associated with the inhibition of TLR4/NF-κB signaling pathway activation.

Effects of different starch structures on energy metabolism in pigs

Background Starch is a major component of carbohydrates and a major energy source for monogastric animals.Starch is composed of amylose and amylopectin and has different physiological functions due to its different structure.It has been shown that the energy supply efficiency of amylose is lower than that of amylopectin.However,there are few studies on the effect of starch structure on the available energy of pigs.The purpose of this study was to measure the effect of different structures of starch in the diet on the net energy(NE)of pigs using a comparative slaughter method and to establish a prediction equation to estimate the NE of starch with different structures.Fifty-six barrows(initial BW 10.18±0.11 kg)were used,and they were housed and fed individually.Pigs were divided into 7 treatments,with 8 replicates for each treatment and 1 pig for each replicate.One of the treatments was randomly selected as the initial slaughter group(ISG).Pigs in the remaining treatments were assigned to 6 diets,fed with basic diet and semi-pure diets with amylose/amylopectin ratio(AR)of 3.09,1.47,0.25,0.15 and 0.12,respectively.The experiment lasted for 28 d.Results Results showed that compared with the high amylose(AM)groups(AR 3.09 and 1.47),the high amylopectin(AP)group(AR 0.15)significantly increased the final BW,average daily weight gain and average daily feed intake of pigs(P<0.05),but the F:G of the AM group was lower(P<0.01).In addition,AR 0.15 and 0.12 groups have higher(P<0.01)nutrient digestibility of dry matter,crude protein,gross energy and crude ash.Meanwhile,compared with other groups,AR 0.15 group has a higher(P<0.05)NE intake and energy retention(RE).The regressive equation for predicting with starch structures was established as RE=1,235.243-48.298AM/AP(R^(2)=0.657,P=0.05).Conclusions In conclusion,NE intake and RE of pigs augmented with the increase of dietary amylopectin content,indicating that diets high in amylopectin were more conducive to promoting the growth of pigs in the late conserva-tion period.

Effect of different dietary protein levels and amino acids supplementation patterns on growth performance, carcass characteristics and nitrogen excretion in growing-finishing pigs

Background:This study was conducted to determine the effects of different dietary protein levels and amino acids supplementation patterns in low protein diets on the growth performance,carcass characteristics and nitrogen excretion in growing-finishing pigs.Forty-two barrows(25.00±0.39 kg)were randomly assigned to 7 diets.Diet 1:the high crude protein diet with balanced for 10 essential amino acids(EAAs).Diet 2:the medium crude protein diet with 2%(approx)decreased protein level of Diet 1 and balanced 10 EAAs.Diet 3:the low crude protein diet with 4%decreased protein level of Diet 1 and balanced 10 EAAs.The protein levels of Diet 4,5,6 and 7 were the same as that of Diet 3.Diet 4 was only balanced for lysine(Lys),methionine(Met),threonine(Thr)and tryptophan(Trp);Diet 5 and 6 were further supplemented with extra isoleucine(Ile)or valine(Val),respectively;Diet 7 was further supplemented with extra Ile+Val.Results:Over the 112 days trial,the reduction of dietary protein by 2%or 4%with balanced10 EAAs significantly decreased nitrogen excretion(P<0.05),but had no effects on growth performance and carcass characteristics(P>0.05).In low protein diet,Val supplementation significantly increased body weight gain at 25–50 kg phase(P<0.05),while Ile supplementation at 75–100 kg phase and 100–125 kg phase significantly reduced the ratio of feed to gain(P<0.05).No effect of different dietary protein levels and amino acids supplementation patterns in low protein diets on carcass characteristics was observed(P>0.05).The total N excretion of pigs supplemented with only Lys,Met,Thr and Trp was numerically higher than that of pigs fed with extra Ile,or Val,or Ile+Val diets.Conclusion:In low protein diet,Val is more required than Ile in the early growing phage(25–50 kg),while Ile becomes more required in the late growing and finishing phage(75–125 kg).

Lentinan administration alleviates diarrhea of rotavirus-infected weaned pigs via regulating intestinal immunity

Background:Lentinan(LNT)may regulate many important physiological functions of human and animals.This study aimed to verify whether LNT administration could relieve diarrhea via improving gut immunity in rotavirus(RV)-challenged weaned pigs.Methods:Twenty-eight weaned pigs were randomly fed 2 diets containing 0 or 84 mg/kg LNT product for 19 d(n=14).RV infection was executed on d 15.After extracting polysaccharides from LNT product,its major monosaccharides were analyzed.Then,LNT polysaccharide was used to administrate RV-infected IPEC-J2 cells.Results:Dietary LNT supplementation supported normal function of piglets even when infected with RV,as reflected by reduced growth performance loss and diarrhea prevalence,and maintained gut immunity(P<0.05).The polysaccharide was isolated from LNT product,which molecular weight was 5303 Da,and major monosaccharides included glucose,arabinose and galactose.In RV-infected IPEC-J2 cells,this polysaccharide significantly increased cell viability(P<0.05),and significantly increased anti-virus immunity via regulating pattern recognition receptors and host defense peptides(P<0.05).Conclusion:Those results suggest that LNT administration increases the piglets’resistance to RV-induced stress,likely by supporting intestinal immunity.

Effect of sialyllactose on growth performance and intestinal epithelium functions in weaned pigs challenged by enterotoxigenic Escherichia Coli

Background:Sialyllactose(SL)is one of the most abundant oligosaccharides present in porcine breast milk.However,little is known about its effect on growth performance and intestinal health in weaned pigs.This study was conducted to explore the protective effect of SL on intestinal epithelium in weaned pigs upon enterotoxigenic Escherichia coli(ETEC)challenge.Methods:Thirty-two pigs were randomly divided into four treatments.Pigs fed with a basal diet or basal diet containing SL(5.0 g/kg)were orally infused with ETEC or culture medium.Results:SL supplementation elevated the average daily gain(ADG)and feed efficiency in the ETEC-challenged pigs(P<0.05).SL also improved the digestibilities of dry matter(DM),gross energy(GE),and ash in non-challenged pigs(P<0.05).Moreover,SL not only elevated serum concentrations of immunoglobulins(IgA,IgG,and IgM),but also significantly decreased the serum concentrations of inflammatory cytokines(TNF-α,IL-1β,and IL-6)upon ETEC challenge(P<0.05).Interestingly,SL increased the villus height,the ratio of villus height to crypt depth(V:C),and the activities of mucosal sucrase and maltase in the jejunum and ileum(P<0.05).SL also elevated the concentrations of microbial metabolites(e.g.acetic acid,propanoic acid,and butyric acid)and the abundance of Lactobacillus,Bifidobacterium,and Bacillus in the cecum(P<0.05).Importantly,SL significantly elevated the expression levels of jejunal zonula occludins-1(ZO-1),occluding,and fatty acid transport protein-4(FATP4)in the ETEC-challenged pigs(P<0.05).Conclusions:SL can alleviate inflammation and intestinal injury in weaned pigs upon ETEC challenge,which was associated with suppressed secretion of inflammatory cytokines and elevated serum immunoglobulins,as well as improved intestinal epithelium functions and microbiota.

Differential expression, molecular cloning,and characterization of porcine beta defensin 114

Background:β-defensins have attracted considerable research interest because of their roles in protecting hosts from various pathogens.This study was conducted to investigate the expression profiles of the porcineβ-defensin114(PBD114)in different breeds and in response to infections.Moreover,the function of PBD114 protein was partially investigated.Methods:Six Tibetan pigs(TP)and six DLY(Duroc×Landrace×Yorkshire)pigs were slaughtered to explore the expression profiles of PBD114 in different breeds and tissues.For infection models,sixteen DLY pigs were divided into two groups and challenged either with sterile saline or E.coli K88.The recombinant protein PBD114(r PBD114)was obtained by using a heterologous expression system in E.coli.Results:PBD114 gene was highly expressed in tissues such as the intestine,liver,spleen,and thymus.Interestingly,the expression level of PBD114 gene was higher in the TP pigs than in the DLY pigs(P<0.05),and was significantly elevated upon E.coli K88 challenge(P<0.05).The nucleotide sequences of PBD114 from Tibetan and DLY pigs was identical,and both showed a 210-bp open reading frame encoding a 69-amino acid mature peptide.To explaore the function of PBD114 protein,PBD114 gene was successfully expressed in E.coli Origami B(DE3)and the molecular weight of the r PBD114 was estimated by SDS-PAGE to be 25 k Da.The r PBD114 was purified and mass spectrometry verified the protein as PBD114.Importantly,r PBD114 showed antimicrobial activities against E.coli DH5αand E.coli K88,and the minimal inhibitory concentrations(MICs)were 64 and 128μg/m L,respectively.Hemolytic and cytotoxicity assays showed that r PBD114 did not affect cell viability under physiological concentrations.Conclusions:PBD114 is an infection response gene that is differentially-expressed between different porcine breeds and tissues.The antimicrobial activity of PBD114 protein,against pathogens such as the E.coli K88,suggested that it may serve as a candidate for the substitution of conventionally used antibiotics.

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.

Effects of a multi-enzyme complex on growth performance,nutrient utilization and bone mineralization of meat duck

Background： Previous studies with broiler have shown dietary supplementation with multi-enzyme complex containing non-starch polysaccharides （NSP） degrading enzymes and phytase is efficient in releasing phosphorus （P）, calcium （Ca）, energy and amino acids from corn-soybean meal diets or corn-sorghum diets, hence compensating considerable levels of nutrients in formulation. Notwithstanding, such potentials have not been well defined in duck nutrition. Giving China being the largest duck producing country, we conducted this study to establish adequate specifications of major nutrients along with multi-enzyme complex to meat duck from day-old to slaughter, focusing on performance, utilization of nutrients and bone mineralization. Five dietary treatments were： Positive control （PC,T1）： the nutrients concentration of diet for 1 to 14 d of age were apparent metabolizable energy（AME） 2,800 kcal/kg, crude protein （CP）1 9.39%, Ca 0.85%, available phosphorus （avP） 0.42%; for 15 to 35 d of age these parameters were AME 2,900 kcal/kg, CP 16.47%,Ca 0.76%,avP 0.38%; Negative control 1（NC1,7-2）, the AME and digestible amino acids （DAA） were reduced by 70 kcal/kg and 2.0%, avP and Ca by 1.0 g/kg from PC diet; Negative control 2（NC2,T4）, the down- spec from PC diet was AME 100 kcal/kg, DAA 2.5%, avP 1.5 g/kg and Ca 1.2 g/kg; The enzyme complex was added at the same dosage （200 mL/1,000 kg） on NC1 （T3） and NC2 （T5） diets. Results： Comparing with the ducks fed on T1, T3 and T5 diets, the birds fed on NC2 diet showed the lowest （P 〈 0.05） body weight （ d 14 and 35）, feed intake （d 35）, tibia ash, Ca and P contents （d 14 and 35）, and the utilization of nutrients （P 〈 0.05）. The supplementation with the enzyme complex to the NC diets restored growth rate, utilization of nutrients and bone mineralization to the level of the PC diet, and increased AME by 60 kcal/kg and 117 kcal/kg, respectively for the NC1 and NC2 diets. Conclusion： These results suggest that down-spec AME by 100 kcal/kg, DAA by 2.5%, avP by 1.5 g/kg and Ca by 1.2 g/kg caused detrimental effects on duck performance compared with those fed on the PC diet, and these performance losses can be compensated by the addition of the multiple-enzyme complex.

Effect of dietary canthaxanthin and 25-hydroxycholecalciferol supplementation on the performance of duck breeders under two different vitamin regimens

Background： Dietary canthaxanthin（CX）, 25-hydroxycholecalciferol（25-OH-D3） and vitamins have been widely reported to be involved in productive and reproductive performance of broiler breeders. However, limited information is available for duck breeders. In this study, a total of 1,560 Cherry Valley SM3 duck breeder females and 312 males were used to assess if the addition of CX and 25-OH-D3 could increase the performance of duck breeders under two different dietary vitamin regimens. Four diets were used under a 2 × 2 factorial arrangement with 2 kinds of vitamin premixes（REGULAR and HIGH; HIGH premix had higher levels of all vitamins except K3 than REGULAR premix）, and with or without the supplementation of the mixture of CX（6 mg/kg） and 25-OH-D3（0.069 mg/kg）. The ducks were fed ad libitum with pelleted diets based on corn-soybean meal from 38 to 77 wk of age.Results： HIGH vitamin premix decreased malondialdehyde（MDA） level（P 〈 0.001） of egg yolk, increased hatchability of fertile eggs（P = 0.029）, increased hatchability of total eggs（P = 0.029）, and decreased serum protein carbonyl level（P = 0.037） of breeder males. The mixture of CX and 25-OH-D3 increased serum calcium of breeder females（P = 0.010）, decreased the cracked egg rate（P = 0.001）, increased the pigmentation of egg yolk（P 〈 0.001）and male bill（P 〈 0.001）, and decreased MDA level of egg yolk（P 〈 0.001） and male serum（P = 0.034）. Interactive effects were observed in cracked egg rate（P = 0.038）, shell thickness（P = 0.011） and serum phosphorus（P = 0.026）of breeder females. HIGH vitamin premix together with the mixture of CX and 25-OH-D3 decreased cracked egg rate and increased shell thickness of duck breeders. Serum phosphorus was decreased in duck breeder females fed REGULAR vitamin premix without the addition of the CX and 25-OH-D3 mixture.Conclusions： Dietary HIGH vitamin premix increased antioxidant status of eggs and breeder males, and increased hatchability. The mixture of CX and 25-OH-D3 enhanced egg shell quality, and promoted pigmentation and antioxidant status of eggs and breeder males.

Secondary bile acids are associated with body lipid accumulation in obese pigs

The aim of this study was to investigate the reasons for the differences in lipid accumulation between lean and obese pigs.The bile acids with varying levels within two types of pigs were found and then in vitro experiments were conducted to identify whether these bile acids can directly affect lipid accumulation.Fourteen pigs,including seven lean and seven obese pigs with body weights of approximately 80 kg,were fed the same diet at an amount approximately equivalent to 3%of their respective body weights daily for 42 d.In vitro,3T3-L1 preadipocytes were cultured in medium with high glucose levels and were differentiated into mature adipocytes using differentiation medium.Then,bile acids were added to mature adipocytes for 4 d.The results showed that there was a difference in body lipids levels and gut microbiota composition between obese and lean pigs(P<0.05).According to the results of gut microbial function prediction,the bile acid biosynthesis in colonic digesta of obese pigs were different from that in lean pig.Sixty-five bile acids were further screened by metabolomics,of which 4 were upregulated(P<0.05)and 2 were downregulated(P<0.05)in obese pigs compared to lean pigs.The results of the correlation analysis demonstrated that chenodeoxycholic acid-3-β-D-glucuronide(CDCA-3Gln)andω-muricholic acid(ω-MCA)had a negative correlation with abdominal fat weight and abdominal fat rate,while isoallolithocholic acid(IALCA)was positively associated with crude fat in the liver and abdominal fat rate.There was a positive correlation between loin muscle area and CDCA-3Gln andω-MCA(P<0.05),however,IALCA and 3-oxodeoxycholic acid(3-oxo-DCA)were negatively associated with loin eye muscle area(P<0.05).Isoallolithocholic acid increased the gene expression of peroxisome proliferator-activated receptor gamma(PPARG)and the number of lipid droplets(P<0.05),promoting the lipid storage when IALCA was added to 3T3-L1 mature adipocytes in vitro.In conclusion,the concentration of bile acids,especially gut microbiota related-secondary bile acids,in obese pigs was different from that in lean pigs,which may contribute to lipid accumulation within obese pigs.

Effect of fermented rapeseed meal on growth performance,nutrient digestibility,and intestinal health in growing pigs

To explore the effects of fermented rapeseed meal(FRSM)on growth performance and intestinal health,a total of 30 growing pigs were randomly allotted to three treatments consisting of corn-soybean meal diet(CSD),rapeseed meal diet(RSD),and fermented rapeseed meal diet(FRSD).Results showed that compared with RSD,FRSD feeding increased the average daily gain and final body weight in pigs(P<0.01).Compared with RSD feeding,FRSD feeding elevated the apparent digestibility of crude protein,acid detergent fiber,and ether extract in pigs(P<0.01).Moreover,the FRSD group exhibited greater apparent ileal digestibility of His,Thr,Lys,and Ser than the RSD group(P<0.01).The digestible energy,metabolic energy,and nitrogen utilization were higher in the FRSD and CSD groups than in the RSD group(P<0.01).As compared to the RSD,FRSD feeding decreased the serum concentration of leptin but significantly increased the concentrations of immunoglobulin(Ig)A,IgG,ghrelin,and enzyme activities of amylase,lipase,and trypsin in the pancreas(P<0.05).Interestingly,the villus height,the ratio of villus height to crypt depth,and the activities of brush border enzymes(e.g.,maltase and sucrase)in the small intestine were higher in the CSD and FRSD groups than in the RSD group(P<0.05).As compared to the RSD,the FRSD feeding not only increased the expression level of the occludin in the small intestinal epithelium(P<0.05)but also elevated the expression levels of claudin-1,MUC1,and PepT1 genes in the duodenum,and elevated the expression levels of SGLT1 and CAT1 genes in the jejunum(P<0.05).Importantly,FRSD feeding significantly decreased the abundance of Escherichia coli,but increased the abundance of Lactobacillus and the content of butyrate in the cecum and colon(P<0.05).These results indicated that compared with rapeseed meal,fermented rapeseed meal exhibited a positive effect on improving the growth performance and intestinal health in growing pigs,and the results may also help develop novel protein sources for animal nutrition and the feed industry.

Effect of dietary supplementation of Bacillus coagulans or yeast hydrolysates on growth performance,antioxidant activity,cytokines and intestinal microflora of growing-finishing pigs

This study was to investigate the effects of dietary supplementation of Bacillus coagulans(BC) and yeast hydrolysates(YH) on growth performance,antioxidant activity,cytokines and intestinal microflora of growing-finishing pigs.Thirty-six barrows(initial BW=26.87±2.65 kg) were assigned randomly to 3 treatments with 4 replicates,3 pigs per replicate.Pigs in the control group(CON) were fed a basal diet,and the diets for the other 2 groups were the basal diet plus BC at 200 mg/kg and the basal diet plus YH at 3,000 mg/kg.The trial lasted for 104 d.Compared with CON,YH treatment significantly increased average daily gain(ADG) and average daily feed intake(ADFI) during the finishing phase(P <0.05),and significantly enhanced ADG during the overall period(P <0.05).Dietary inclusion of BC tended to increase ADFI during the finishing period(P=0.08).Compared with CON,BC treatment imp roved lysozyme(LZM),complement 3(C3),complement 4(C4),interlenkin-10(IL-10) and total antioxidant capacity(T-AOC) level in serum(P <0.05).Dietary inclusion of YH enhanced the serum IL-10 level(P <0.05) and tended to increase T-AOC level(P=0.06).Dietary inclusion of YH elevated(P <0.05) the number of Lactobacillus and Bacillus in cecal contents of pigs,promoted the populations of Bifidobacterium and Bacillus in colonic contents.Moreover,the BC diet increased(P <0.05) the count of Bifidobacterium in colonic contents.These results indicated that dietary BC supplementation is beneficial to improve the immunity.Dietary YH supplementation promoted the growth performance and the populations of beneficial bacteria in the hindgut of the growing-finishing pigs.

Effects of benzoic acid,Bacillus coagulans and oregano oil combined supplementation on growth performance,immune status and intestinal barrier integrity of weaned piglets

This experiment was conducted to investigate the effects of benzoic acid,Bacillus coagulans and oregano oil combined supplementation on growth performance,immune status and intestinal barrier integrity of piglets.In a 26-d experiment,25 piglets were randomly assigned to 5 treatments:1)a basal diet,negative control(NC),2)NC added with antibiotics,positive control(PC);3)NC added with benzoic acid at 3,000 g/t and Bacillus coagulans at 400 g/t(AB);4)NC added with benzoic acid at 3,000 g/t and o regano oil at 400 g/t(AO);5)NC added with 3,000 g/t benzoic acid and Bacillus coagulans at 400 g/t and oregano oil at 400 g/t(ABO);On d 27,all piglets were euthanized to obtain jejunal mucosa to measure immune status and intestinal barrier integrity.Results showed that pigs fed AB diet increased the final body weight and average daily body weight gain and decreased the ratio of feed to gain co mpared with NC group(P<0.05).Co mpared with NC group,AB,AO and ABO decreased serum tumor necrosis factor-a concentration and ABO decreased interleukin-1βconcentration in serum and jejunal mucosa(P<0.05).Compared with NC group,AB upregulated mRNA expressions of sodium-glucose cotransportel,claudin-1,occludin and mucin2 in jejunal mucosa and the populations of Bifidobacterium and Bacillus in cecal digesta(P<0.05).Compared with NC group,ABO increased jejunal mucosal occludin mRNA abundance and Bifidobacterium population in cecal digesta,and decreased Escherichia coli population in cecal digesta(P<0.05).Furthermore,AB and ABO increased Bacillus population in cecal digesta compared with PC group(P<0.05).These results indicated that dietary AB supplementation could improve growth performance and intestinal barrier integrity of piglets when fed antibiotic-free diets,which was possibly associated with the improvement of immune status and intestinal microflora.Dietary ABO supplementation is also beneficial to improve immune status and intestinal barrier integrity and micro flora of piglets.

Dietary lycopene supplementation improves meat quality,antioxidant capacity and skeletal muscle fiber type transformation in finishing pigs

This study aimed to investigate effects of dietary lycopene supplementation on meat quality,antioxidant ability and muscle fiber type transformation in finishing pigs.In a 70-day experiment,18 DurocLandraceYorkshire barrows were randomly allocated to 3 dietary treatments including a basal diet supplemented with 0,100 and 200 mg/kg lycopene,respectively.Each dietary treatment had 6 replicates with one pig each.Results showed that dietary 200 mg/kg lycopene supplementation increased muscle redness a^(*)value,intramuscular fat and crude protein contents,and decreased muscle lightness L^(*)and yellowness b^(*)values(P<0.05),suggesting that addition of 200 mg/kg lycopene to the diet of finishing pigs improved color,nutritional value and juiciness of pork after slaughter.Results also showed that dietary lycopene supplementation enhanced antioxidant capacity of finishing pigs(P<0.05).Moreover,dietary supplementation of 200 mg/kg lycopene significantly increased slow myosin heavy chain(MyHC)protein level and slow-twitch fiber percentage,and decreased fast MyHC protein level and fast-twitch fiber percentage(P<0.05),suggesting that the addition of 200 mg/kg lycopene to the diet of finishing pigs promoted muscle fiber type conversion from fast-twitch to slow-twitch.Together,we provide the first evidence that dietary 200 mg/kg lycopene supplementation improves meat quality,enhances antioxidant capacity and promotes muscle fiber type transformation from fast-twitch to slow-twitch in finishing pigs.

Infusion of short chain fatty acids in the ileum improves the carcass traits,meat quality and lipid metabolism of growing pigs

Short chain fatty acids(SCFA)are the main products of indigestible carbohydrates undergoing bacterial fermentation in the hindgut,which are related to some physiological functions.This study was designed to investigate the effects of SCFA infusion by ileum on the carcass traits,meat quality and lipid meta-bolism of growing pigs.In a 28-day study,24 growing barrows fitted with a T-cannula in distal ileum were divided into 4 treatments:1)Control,2)antibiotics(AB),3)AB+300 mL of SCFA1 solution(ABS1),4)AB+300 mL of SCFA2 solution(ABS2).The concentrations of acetate,propionate and butyrate in SCFA1 solution were respectively 61.84,18.62 and 12.55 mmol/L,and in SCFA2 were respectively 40.08,15.41 and 9.78 mmol/L The results showed that the SCFA infusion increased the average daily feed intake and average daily gain of pigs(P<0.05).Meanwhile,the SCFA treatments increased longissimus dorsi area(P<0.05)and carcass weight(P=0.058),decreased the drip loss of longissimus dorsi(P=0.059),and reduced serum concentrations of triglyceride,total cholesterol and urea nitrogen(P<0.05).Besides,the SCFA administration inhibited the mRNA expressions of fatty acid synthase(FAS)and acetyl-CoA carboxylase in longissimus dorsi(P<0.05),the mRNA expression of FAS in the liver(P<0.05),and the mRNA expression of hormone-sensitive lipase in abdominal fat(P<0.05).Short chain fatty acid infusion also enhanced the mRNA expression of carnitine palmitoyltransferase-1αin the liver(P<0.05),the mRNA expressions of peroxisome proliferator activated receptor gamma and lipoprotein lipase in abdominal fat(P<0.05),and the mRNA expressions of free fatty acid receptor 2,glucose-6-phosphatase and phosphoenolpyruvate carboxykinase 1 in the colon(P<0.05).These results suggested that SCFA administration in the ileum could improve the carcass traits and meat quality of growing pigs,which was possibly due to the fact that SCFA modulated lipid metabolism.

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-y-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.

Supplementing daidzein in diets improves the reproductive performance, endocrine hormones and antioxidant capacity of multiparous sows

Certain hormones play important roles in modulating mammalian reproductive behaviour.Daidzein is a well-known isoflavonic phytoestrogen that possesses oestrogenic activity.This study was conducted to probe the effects of daidzein supplementation in gestation diets on the reproductive performance in sows.A total of 120 multiparous sows(Landrace x Yorkshire)were randomly assigned to 2 groups(n=60)and fed either a base diet(control)or one containing 200 mg/kg daidzein during gestation.We discovered that daidzein supplementation significantly increased the total number of piglets born per litter and number of piglets born alive per litter(P<0.05),decreased the farrowing time(P<0.05)and increased the serum oestrogen and progesterone concentrations(P<0.05)at 35 d of gestation.Moreover,serum immunoglobulin G(IgG)concentration and superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)activities were higher in the daidzein-treated group than in the control group at35 d of gestation(P<0.05).Daidzein increased the serum SOD activity and total anti-oxidative capacity(T-AOC)at 85 d of gestation(P<0.05).Interestingly,daidzein elevated the expression levels of the sodium-coupled neutral amino acid transporter 1(SLC38 A1)and insulin-like growth factor 1(IGF-1)genes in the placenta(P<0.05).These results suggest that daidzein ingestion could improve sow reproductive performance by changing serum hormones,elevating anti-oxidative capacity and upregulating critical functional genes in the placenta.

Lower abundance of Bacteroides and metabolic dysfunction are highly associated with the post-weaning diarrhea in piglets

Growing evidences show a direct link between diarrhea and disorders of gut microbiota in pigs.However,whether there are microbial markers associated with post-weaning diarrhea remains unknown.In the current study,we compared the microbial community,functions and metabolites between healthy weaned piglets(group H,n=7)and piglets with post-weaning diarrhea(group D,n=7),in order to find out diarrhea associated microbial markers.Each of 7 fecal samples was collected from H and D piglets(weaned at 21 d and sampled at 26 d).The metagenomic and untargeted metabolomic analysis revealed that the microbial composition,function and metabolic profile in D pigs was considerably reshaped,including the reduced abundance and number of Bacteroides,which significantly correlated with the diarrhea status of host.The carbohydrate metabolism,biosynthesis and metabolism,lipid metabolism,amino acid metabolism,and the activity of glycan and carbohydrates digestion related enzymes showed extensively down-regulated in D pigs compared with H pigs.Diarrhea significantly changed the metabolic profiles of fecal microbiota,and most of the altered metabolites were negatively or positively correlated with the change in the abundance of Bacteroides.In conclusion,the lower abundance of Bacteroides and its associated metabolic dysfunction may be regarded as microbial markers of physiological post-weaning diarrhea in piglets.

Prevotella-rich enterotype may benefit gut health in finishing pigs fed diet with a high amylose-to-amylopectin ratio

To investigate the influence of baseline enterotypes and dietary starch type on the concentration of short-chain fatty acids(SCFA),numbers of butyrate producing bacteria and the expression of genes related to intestinal barrier and inflammatory response in the colon of finishing pigs,a 60-d in vivo trial was conducted.A 2-wk pre-trial with 102 crossbred(Duroc×[Landrace×Yorkshire])finishing barrows(90 d old)was conducted to screen enterotypes.Then,a total of 32 pigs(87.40±2.76 kg)with high(HPBR,>14)and low(LPBR,<2)Prevotella-to-Bacteroides ratios(PBR)in equal measure were selected and randomly divided into 4 groups with 8 replicates per group and 1 pig per replicate.The trial was designed following a 2(PBR)×2(amylose-to-amylopectin ratio,AMR)factorial arrangement.Pigs with different PBR were fed diets based on corn-soybean meal with high AMR(HAMR,1.24)or low AMR(LAMR,0.23),respectively.Results showed that neither PBR nor AMR influenced the growth performance of pigs.HPBR pigs fed HAMR diet had a higher number of colonic Clostridium cluster XIVa and higher gene expression of butyrate kinase compared to the LPBR pigs(P<0.05).The HPBR pigs fed HAMR diets also had increased colonic concentrations of total SCFA and propionate compared to the LPBR pigs(P<0.05).Comparing with other pigs,HPBR pigs fed HAMR diets showed a lower(P<0.05)expression of histone deacetylases(HDAC)gene and higher(P<0.05)expression of G protein-coupled receptor 43 gene(GPR 43)in the colonic mucosa.The interaction(P<0.05)of HPBR and HAMR was also found to decrease the gene expression of interleukin(IL)-6,IL-12,IL-1βand tumor necrosis factor-α(TNF-α)in colonic mucosa.These findings show that HAMR diet increased the abundance and activity of butyrate-producing bacteria and the concentration and absorption of SCFA,which may be associated with the decreased gene expression of inflammatory cytokines in the colonic mucosa of pigs with Prevotella-rich enterotype.All these alterations are likely to have a positive effect on the intestinal health of finishing pigs.