Effects of methionine supplementation in a reduced protein diet on growth performance, oxidative status, intestinal health, oocyst shedding, and methionine and folate metabolism in broilers under Eimeria challenge

Background This study investigated effects of different methionine(Met)supplementation levels in a reduced protein diet on growth performance,intestinal health,and different physiological parameters in broilers under Eimeria challenge.A total of 600 fourteen-day-old Cobb500 male broilers were challenged with E.maxima,E.tenella,and E.acervulina,and randomly allocated in a 2×5 factorial arrangement.Birds received normal protein diets(20%crude protein,NCP)or reduced protein diets(17%crude protein,LCP),containing 2.8,4.4,6.0,7.6,and 9.2 g/kg of Met.Results On 6 and 9 days post inoculation(DPI),increasing Met level linearly improved the growth performance(P<0.05).Total oocyst shedding linearly increased as Met level increased(P<0.05).Duodenal villus height(VH):crypt depth(CD)in the LCP groups were higher on 6 DPI(P<0.01)while lower on 9 DPI(P<0.05)compared to the NCP groups.Jejunal CD and duodenal VH:CD changed quadratically as Met level increased(P<0.05).On 6 DPI,liver glutathione(GSH)and glutathione disulfide(GSSG)linearly increased as Met level increased(P<0.05).On 9 DPI,GSSG quadratically increased,whereas GSH:GSSG quadratically decreased as Met levels increased(P<0.05).The expression of amino acid transporters linearly decreased as Met level increased(P<0.05).The expression of zonula occludens 2 and claudin-1 linearly increased on 6 DPI whereas decreased on 9 DPI as Met level increased(P<0.05).The expressions of cytokines were lower in the LCP groups than the NCP groups(P<0.05).Interaction effects were found for the expression of IL-10 and TNFαon 6 DPI(P<0.05),where it only changed quadratically in the NCP group as Met level increased.The expression of Met and folate metabolism genes were lower in the LCP groups than the NCP groups on 9 DPI(P<0.05).The expression of these genes linearly or quadratically decreased as Met level increased(P<0.05).Conclusion These results revealed the regulatory roles of Met in different physiological parameters including oxidative status,intestinal health,and nutrient metabolism in birds fed reduced protein diet and challenged with Eimeria.

Investigation of the nutritional and functional roles of a combinational use of xylanase and β-glucanase on intestinal health and growth of nursery pigs

Background Xylanase andβ-glucanase combination(XG)hydrolyzes soluble non-starch polysaccharides that are anti-nutritional compounds.This study aimed to evaluate the effects of increasing levels of XG on intestinal health and growth performance of nursery pigs.Methods Forty pigs(6.5±0.4 kg)were assigned to 5 dietary treatments and fed for 35 d in 3 phases(11,9,and 15 d,respectively).Basal diets mainly included corn,soybean meal,and corn distiller's dried grains with solubles,contained phytase(750 FTU/kg),and were supplemented with 5 levels of XG at(1)0,(2)280 TXU/kg xylanase and 125 TGU/kgβ-glucanase,(3)560 and 250,(4)840 and 375,or(5)1,120 and 500,respectively.Growth performance was measured.On d 35,all pigs were euthanized and jejunal mucosa,jejunal digesta,jejunal tissues,and ileal digesta were collected to determine the effects of increasing XG levels and XG intake on intestinal health.Results Increasing XG intake tended to quadratically decrease(P=0.059)viscosity of jejunal digesta(min:1.74 m Pa·s at 751/335(TXU/TGU)/kg).Increasing levels of XG quadratically decreased(P<0.05)Prevotellaceae(min:0.6%at 630/281(TXU/TGU)/kg)in the jejunal mucosa.Increasing XG intake quadratically increased(P<0.05)Lactobacillaceae(max:40.3%at 608/271(TXU/TGU)/kg)in the jejunal mucosa.Increasing XG intake quadratically decreased(P<0.05)Helicobacteraceae(min:1.6%at 560/250(TXU/TGU)/kg)in the jejunal mucosa.Increasing levels of XG tended to linearly decrease(P=0.073)jejunal Ig G and tended to quadratically increase(P=0.085)jejunal villus height to crypt depth ratio(max:2.62 at 560/250(TXU/TGU)/kg).Increasing XG intake tended to linearly increase the apparent ileal digestibility of dry matter(P=0.087)and ether extract(P=0.065).Increasing XG intake linearly increased(P<0.05)average daily gain.Conclusions A combinational use of xylanase andβ-glucanase would hydrolyze the non-starch polysaccharides fractions,positively modulating the jejunal mucosa-associated microbiota.Increased intake of these enzyme combination possibly reduced digesta viscosity and humoral immune response in the jejunum resulting in improved intestinal structure,and ileal digestibility of nutrients,and finally improving growth of nursery pigs.The beneficial effects were maximized at a combination of 550 to 800 TXU/kg xylanase and 250 to 360 TGU/kgβ-glucanase.

Low crude protein formulation with supplemental amino acids for its impacts on intestinal health and growth performance of growing-finishing pigs

Background Low crude protein(CP)formulations with supplemental amino acids(AA)are used to enhance intestinal health,reduce costs,minimize environmental impact,and maintain growth performance of pigs.However,extensive reduction of dietary CP can compromise growth performance due to limited synthesis of non-essential AA and limited availability of bioactive compounds from protein supplements even when AA requirements are met.Moreover,implementing a low CP formulation can increase the net energy(NE)content in feeds causing excessive fat deposition.Additional supplementation of functional AA,coupled with low CP formulation could further enhance intestinal health and glucose metabolism,improving nitrogen utilization,and growth performance.Three experiments were conducted to evaluate the effects of low CP formulations with supplemental AA on the intestinal health and growth performance of growing-finishing pigs.Methods In Exp.1,90 pigs(19.7±1.1 kg,45 barrows and 45 gilts)were assigned to 3 treatments:CON(18.0%CP,supplementing Lys,Met,and Thr),LCP(16.0%CP,supplementing Lys,Met,Thr,Trp,and Val),and LCPT(16.1%CP,LCP+0.05%SID Trp).In Exp.2,72 pigs(34.2±4.2 kg BW)were assigned to 3 treatments:CON(17.7%CP,meeting the requirements of Lys,Met,Thr,and Trp);LCP(15.0%CP,meeting Lys,Thr,Trp,Met,Val,Ile,and Phe);and VLCP(12.8%CP,meeting Lys,Thr,Trp,Met,Val,Ile,Phe,His,and Leu).In Exp.3,72 pigs(54.1±5.9 kg BW)were assigned to 3 treatments and fed experimental diets for 3 phases(grower 2,finishing 1,and finishing 2).Treatments were CON(18.0%,13.8%,12.7%CP for 3 phases;meeting Lys,Met,Thr,and Trp);LCP(13.5%,11.4%,10.4%CP for 3 phases;meeting Lys,Thr,Trp,Met,Val,Ile,and Phe);and LCPG(14.1%,12.8%,11.1%CP for 3 phases;LCP+Glu to match SID Glu with CON).All diets had 2.6 Mcal/kg NE.Results In Exp.1,overall,the growth performance did not differ among treatments.The LCPT increased(P<0.05)Claudin-1 expression in the duodenum and jejunum.The LCP and LCPT increased(P<0.05)CAT-1,4F2hc,and B0AT expressions in the jejunum.In Exp.2,overall,the VLCP reduced(P<0.05)G:F and BUN.The LCP and VLCP increased(P<0.05)the backfat thickness(BFT).In Exp.3,overall,growth performance and BFT did not differ among treatments.The LCPG reduced(P<0.05)BUN,whereas increased the insulin in plasma.The LCP and LCPG reduced(P<0.05)the abundance of Streptococcaceae,whereas the LCP reduced(P<0.05)Erysipelotrichaceae,and the alpha diversity.Conclusions When implementing low CP formulation,CP can be reduced by supplementation of Lys,Thr,Met,Trp,Val,and Ile without affecting the growth performance of growing-finishing pigs when NE is adjusted to avoid increased fat deposition.Supplementation of Trp above the requirement or supplementation of Glu in low CP formulation seems to benefit intestinal health as well as improved nitrogen utilization and glucose metabolism.

Comparative effects of soy protein concentrate,enzyme‑treated soybean meal,and fermented soybean meal replacing animal protein supplements in feeds on growth performance and intestinal health of nursery pigs

Background Soy protein supplements,with high crude protein and less antinutritional factors,are produced from soybean meal by different processes.This study evaluated the comparative effects of various soy protein supplements replacing animal protein supplements in feeds on the intestinal immune status,intestinal oxidative stress,mucosaassociated microbiota,and growth performance of nursery pigs.Methods Sixty nursery pigs(6.6±0.5 kg BW)were allotted to five treatments in a randomized complete block design with initial BW and sex as blocks.Pigs were fed for 39 d in 3 phases(P1,P2,and P3).Treatments were:Control(CON),basal diet with fish meal 4%,2%,and 1%,poultry meal 10%,8%,and 4%,and blood plasma 4%,2%,and 1%for P1,P2,and P3,respectively;basal diet with soy protein concentrate(SPC),enzyme-treated soybean meal(ESB),fermented soybean meal with Lactobacillus(FSBL),and fermented soybean meal with Bacillus(FSBB),replacing 1/3,2/3,and 3/3 of animal protein supplements for P1,P2,and P3,respectively.Data were analyzed using the MIXED procedure in SAS 9.4.Results The SPC did not affect the BW,ADG,and G:F,whereas it tended to reduce(P=0.094)the ADFI and tended to increase(P=0.091)crypt cell proliferation.The ESM did not affect BW,ADG,ADFI,and G:F,whereas tended to decrease(P=0.098)protein carbonyl in jejunal mucosa.The FSBL decreased(P<0.05)BW and ADG,increased(P<0.05)TNF-α,and Klebsiella and tended to increase MDA(P=0.065)and IgG(P=0.089)in jejunal mucosa.The FSBB tended to increase(P=0.073)TNF-α,increased(P<0.05)Clostridium and decreased(P<0.05)Achromobacter and alpha diversity of microbiota in jejunal mucosa.Conclusions Soy protein concentrate,enzyme-treated soybean meal,and fermented soybean meal with Bacillus could reduce the use of animal protein supplements up to 33%until 7 kg body weight,up to 67%from 7 to 11 kg body weight,and entirely from 11 kg body weight without affecting the intestinal health and the growth performance of nursery pigs.Fermented soybean meal with Lactobacillus,however,increased the immune reaction and oxidative stress in the intestine consequently reducing the growth performance.

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

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

Effects of tannic acid on the immunity and intestinal health of broiler chickens with necrotic enteritis infection

Background In broiler chickens,necrotic enteritis(NE)infection can reduce production performance.Tannic acid has shown great potential as a treatment of NE in broilers.However,the appropriate dosage of tannic acid in NE of broilers and the improvement effect on intestinal health are not very clear.In this study,we aimed to investigate the effects of different doses of tannic acid on the production performance,immunity,and intestinal health of broilers by constructing an NE model with C.perfringens infection and determining the appropriate dosage of tannic acid with regard to NE.Results Challenged birds showed significant reduction in body weight,villus height,and the ratio of villus height to crypt depth(P<0.05)and increase in the feed consumption gain ratio,intestinal lesion score,and crypt depth(P<0.05).The infection significantly reduced the relative Bacteroidota and Ligilactobacillus abundance(P<0.05)and increased the ratio of Firmicutes/Bacteroidota and cecal content of C.perfringens(P<0.05).Challenged birds fed diets supplemented with tannic acid showed significantly increased mRNA expression of nutrient transport carriers and intestinal barrier genes and growth performance and reduced serum zonulin and endotoxin levels(P<0.05).Addi-tion of tannic acid to the diet inhibited the inflammatory response by reducing the number of coccidia oocysts in feces and the content of C.perfringens in the cecum.Specifically,tannic acid reduced the serum levels of C reactive protein,myeloperoxidase,and specific IgY and ileal mucosal secretory immunoglobulin A levels in the ileal mucosa compared with those in the NE-infected birds.NE-infected birds fed diets supplemented with tannic acid also showed significantly increased relative Anaerocolumna,Thermoanaerobacterium,and Thermosinus abundance(P<0.05);their microbial composition and functional predictions were similar to those of the NC group.Conclusions Tannic acid in the diet alleviated NE by enhancing the intestinal barrier and absorption function.The recommended dietary tannic acid additive level is 500–750 mg/kg.Our study findings would be useful in reducing related economic losses in the broiler industry.

Dietary oregano aqueous extract improves growth performance and intestinal health of broilers through modulating gut microbial compositions

Background Intestinal health plays a pivotal role in broiler chicken growth.Oregano aqueous extract(OAE)effec-tively exerts anti-inflammatory and antibacterial effects.However,the protective effects of OAE on intestinal health in broilers and the underlying mechanism remain unclear.This study aimed to investigate the potential effects of OAE on growth performance,the gut microbiota and intestinal health.A total of 8401-d-old male and female broilers(Arbor Acres)were randomly allocated into 6 groups as follows:basal diet(Con),Con+antibiotics(Anti,colistin sulfate 7 g/kg,roxarsone 35 g/kg),Con+400,500,600 and 700 mg/kg OAE(OAE400,OAE500,OAE600 and OAE700).Subse-quently,fermentation in vitro together with oral administration trials were carried out to further assess the function of OAE on intestinal health of broilers.Results Dietary 700 mg/kg OAE supplementation resulted in an increase(P<0.05)in body weight and a decrease(P<0.05)in feed conversion ratio when compared with the control during d 22 to 42 of the trial.OAE addition resulted in lower(P<0.05)jejunal crypt depth and mRNA expression of IL-4 and IL-10 at d 42.In addition,dietary OAE addition increased the abundance of Firmicutes(P=0.087)and Lactobacillus(P<0.05)in the cecum,and increased(P<0.05)the content of acetic acid and butyric acid.In the in vitro fermentation test,OAE significantly increased(P<0.05)the abundance of Lactobacillus,decreased(P<0.05)the abundance of unspecified_Enterobacteriaceae,and increased the content of acetic acid(P<0.05).In the oral administration trial,higher(P<0.05)IL-4 expression was found in broilers when oral inoculation with oregano fermentation microorganisms at d 42.And SIgA content in the ileum was significantly increased(P=0.073)when giving OAE fermentation supernatant.Conclusions Dietary OAE addition could maintain intestinal health and improve growth performance through enhancing intestinal mucosal immunity and barrier function mediated by gut microbiota changes.

Effects of creep feeding and supplemental glutamine or glutamine plus glutamate (Aminogut) on pre- and post-weaning growth performance and intestinal health of piglets

Background： Creep feeding is used to stimulate piglet post-weaning feed consumption.L-Glutamine（GLN） is an important source of fuel for intestinal epithelial cells.The objective of this study was to determine the impact of creep feeding and adding GLN or AminoGut（AG;containing glutamine ＋ glutamate） to pre-and post-weaning diets on pig performance and intestinal health.Litters（N = 120） were allotted to four treatments during 14–21 d of lactation： 1） No creep feed（NC,n = 45）;2） creep fed control diet（CFCD,n = 45）;3） creep fed 1% GLN（CFGLN,n = 15）;4） creep fed.88% AG（CFAG,n = 15）.After weaning,the NC and CFCD groups were sub-divided into three groups（n = 15 each）,receiving either a control nursery diet（NC-CD,CFCD-CD） or a diet supplemented with either GLN（NC-GLN,CFCD-GLN） or with AG（NC-AG,CFCD-AG）.Litters that were creep fed with diets containing GLN or AG also were supplemented with those amino acids in the nursery diets（CFGLN-GLN,CFAG-AG）.Glutamine was added at 1% in all three post-weaning diet phases and AG was added at.88% in phase 1 and 2 and at.66% in phase 3.Results： Feed conversion（feed/gain） showed means among treatment means close to significance（P = 0.056） and Tukey＇s test for pairwise mean comparisons showed that Pigs in the CFGLN-GLN group had the best feed conversion（feed/gain） in the first three-week period post-weaning,exceeding（P = 0.044） controls（CFCD-CD） by 34%.The NC-AG group had（P = 0.02） the greatest feed intake in the last three week of the study,exceeding controls（CFCD-CD） by 12%.CFGLN-GLN,CFCD-GLN and sow reared（SR） pigs had the greatest（P = 0.049） villi height exceeding the CFCD-AG group by 18%,20% and 19% respectively.The CFAG-AG group had the deepest（P = 0.001） crypts among all treatments.CFGLN-GLN,CFCD-GLN and SR groups had the greatest（P = 0.001） number of cells proliferating（PCNA） exceeding those in the NC-CD group by 43%,54% and 63% respectively.Sow reared pigs showed the greatest（P = 0.001） intestinal absorption capacity for xylose and mannitol.Conclusion： Supplementation of creep feed and nursery diets with GLN and/or AminoGut in the first three week improved feed conversion possibly due to improved intestinal health.

Effects of different amino acid levels and a carvacrol-thymol blend on growth performance and intestinal health of weaned pigs

Background:Over the past years,antibiotic growth promoter had been restricted in animal husbandry production in many countries because of antimicrobial resistance and foodborne antibiotic residues.However,the problems of poor intestinal health and low growth efficiency of piglets have not been solved completely in an antibiotic-free diet,and it is urgent to explore alternatives to antimicrobial growth promoters.Methods:Here,a total of 532 weaned pigs were assigned to one of 4 treatments,the low amino acid(AA)level diet(d 1 to d 14 is 1.35%,d 15 to d 42 is 1.25%)(Low AA),the low AA level diet supplementation with a carvacrol-thymol blend(50 mg carvacrol and 50 mg thymol/kg of diet)(CB)(Low AA+CB),the high AA level diet(d 1 to d 14 is 1.50%,d 15 to d 42 is 1.40%)(High AA),and the high AA level diet supplementation with a CB(High AA+CB),respectively.Then we measured growth performance and intestinal health indicators of weaned pigs.Results:Results showed that high AA level significantly reduced plasma urea nitrogen,plasma Interleukin-6(IL-6)and fecal lipocalin-2 contents(P<0.05),significantly increased the relative abundance of fecal Lactobacillus and Enterococcus,and had a trend to increase the fecal secretory immunoglobulin A(sIgA)and mucin 2(MUC 2)contents(P<0.05)in piglets,thereby alleviating the diarrhea of piglets and reducing the feed conversion ratio(FCR)of piglets during d 1~14 after weaning.Dietary supplementation with CB significantly increased the activity of plasma antioxidant enzymes T-SOD and GSH-px(P<0.05),while significantly reduced plasma malondialdehyde(MDA),plasma interleukin-1β(IL-1β),plasma endotoxin and D-lactic acid contents(P<0.05).Meanwhile,CB significantly decreased fecal lipocalin-2 contents and the abundance of fecal Escherichia coli(P<0.05).Thus,we hypothesis that dietary supplementation with CB significantly increased the average daily gain(ADG)of piglets(P<0.05)during d 1~14 after weaning through promoting intestinal health.Conclusion:These results suggest that high AA level and dietary supplementation with CB improved the growth performance of weaned pigs in an antibiotic-free diet by improving AA metabolism and intestinal antioxidant capacity.

Digestibility and metabolism of copper in diets for pigs and influence of dietary copper on growth performance,intestinal health,and overall immune status:a review

The current contribution reviews absorption and metabolism of copper(Cu),Cu deficiency,Cu toxicity,Cu bioavailability,and effects of pharmacological levels of Cu on growth performance and intestinal health of pigs.Copper is a micro mineral involved in metabolic reactions including cellular respiration,tissue pigmentation,hemoglobin formation,and connective tissue development.Copper is mostly absorbed in the upper gastrointestinal tract,particularly in the duodenum,but some Cu is absorbed in the stomach.One way to evaluate the efficacy of sources of Cu is to measure relative bioavailability where responses include tissue concentrations of Cu,concentrations of metalloproteins,and enzymatic activity of animals fed test diets containing graded levels of Cu.The requirement for Cu by pigs is 5 to 10 mg/kg diet,however,Cu can be included at growth-promoting levels(i.e.,75 to 250 mg/kg diet)in diets for weanling and growing pigs to reduce post-weaning diarrhea and improve growth performance.The consistently observed improvement in growth performance upon Cu supplementation is likely a result of increases in lipase activity,growth hormone secretion,and expression of genes involved in postabsorptive metabolism of lipids.The growth-promoting effects of dietary Cu have also been attributed to its bacteriostatic and bactericidal properties because Cu may change bacterial populations in the intestine,and thereby reduce inflammation caused by pathogens.However,further research is needed to determine potential interactions between Cu and non-nutritive feed additives(e.g.,enzymes,probiotics,phytobiotics),and the optimum quantity of Cu as well as the optimum duration of feeding supplemental Cu in diets for pigs should be further investigated.These gaps needs to be addressed to maximize inclusion of Cu in diets to improve growth performance while minimizing diseases and mortality.

Review: Effects of Dietary Fiber Levels and Composition on the Intestinal Health of Finishing Pigs

Despite the fact that dietary fiber is predominant in common feedstuff, its level in the diets of monogastrics has seen a proportional increment with the inclusion of co-products. The source and composition of DF could be liable for enormous varieties in their use. A study carried out by scientists proposed that three major components constitute gut health: the diet, the mucosa, and the commensal microbiota. 70% of total body immune cells constitute the gastrointestinal tract of pigs, therefore it is important that it is included when defining intestinal health. Gut health is of substantial importance in the maintenance of growth performance and overall health of monogastrics. The fermentation of DF results in SCFA which enhances mucosal epithelial proliferation and villus height. Nonetheless, supplementing dietary fiber to the diet in moderation may result in an increase in gut size, volume, length and morphological structure of pigs and other non-ruminants. Gut health maintenance exhibits a certain level of complexity and a subtle balance between mucosa, diet, the commensal microflora, including the digestive epithelium and along with mucous overlaying it. The microbial changes of dietary fiber to monosaccharides in the gut include various principal occasions (reactions) intervened by the enzymatic collection of particularized groups from the gut microbiota. Because fermentation is dependent upon source, structure and physio-chemical properties of dietary fiber, it is therefore of great importance to have as much data as possible on various types of dietary fiber and how intestinal health can be enhanced by them. Thus, there is growing evidence that dietary fiber may have prebiotic effects in pigs. In addition, dietary fiber in diets improves pigs well-being by increasing satiety, influencing behaviour and improving overall health. This review aims to shed more light on the dietary fiber levels and composition on the intestinal health of finishing pigs.

Role of milk carbohydrates in intestinal health of nursery pigs: a review

Intestinal health is essential for the resistance to enteric diseases and for nutrient digestion and absorption to support growth.The intestine of nursery pigs are immature and vulnerable to external challenges,which cause negative impacts on the structure and function of the intestine.Among nutritional interventions,the benefits of milk are significant for the intestinal health of pigs.Milk coproducts have traditionally been used in starter feeds to improve the growth of nursery pigs,but their use is somewhat limited due to the high costs and potential risks of excessive lactose on the intestine.Thus,understanding a proper feeding level of milk carbohydrates is an important start of the feeding strategy.For nursery pigs,lactose is considered a highly digestible energy source compared with plant-based starch,whereas milk oligosaccharides are considered bioactive compounds modulating intestinal immunity and microbiota.Therefore,milk carbohydrates,mainly composed of lactose and oligosaccharides,have essential roles in the intestinal development and functions of nursery pigs.The proper feeding levels of lactose in starter feeds could be variable by weaning age,body weight,or genetic lines.Effects of lactose and milk oligosaccharides have been broadly studied in human health and animal production.Therefore,this review focuses on the mechanisms of lactose and milk oligosaccharides affecting intestinal maturation and functions through modulation of enterocyte proliferation,intestinal immunity,and intestinal microbiota of nursery pigs.

The prevention role of Spirulina platensis(Arthrospira platensis)on intestinal health

Spirulina is a popular herbal food that has a preventive effect on health.In the study,it aimed to evaluate the effects of different doses of Spirulina platensis(Arthrospira platensis)on the morphological properties of the duodenum of rats,and to assign the effect of Spirulina on the expression of proliferating cell nuclear antigen(PCNA)in the rat duodenum,and thereby to observe the effects on intestinal health.30 male Wistar albino rats were divided into 3 groups for 45 days.The first group was received the basal diet;the second group was given 500 mg/kg Spirulina daily by oral gavage;the third group was given 1000 mg/kg Spirulina daily.The duodenum segments were taken at the end of the trial and processed for histological assay.Although the total mucosa,villus height and villus/cript ratio were found higher in high dose Spirulina,the lower cript depth was detected in same group compared to control and low dose group.A significant increase was observed at high dose compared to the control and low dose group in terms of PCNA expression intensity and proliferation index.Findings suggest that high dose of Spirulina may support the duodenal growth,and thereby intestinal health.

Essential oils improve nursery pigs'performance and appetite via modulation of intestinal health and microbiota

Optimal intestinal health and functionality are essential for animal health and performance,and simultaneously intestinal nutrient transporters and intestinal peptides are also involved in appetite and feed intake control mechanisms.Given the potential of essential oil(EO)in improving animal performance and improving feed palatability,we hypothesized that dietary supplementation of cinnamaldehyde and carvacrol could improve performance and appetite of nursery pigs by modulating intestinal health and microbiota.Cinnamaldehyde(100 mg/kg),carvacrol(100 mg/kg),and their mixtures(including 50 mg/kg cinnamaldehyde and 50 mg/kg carvacrol)were supplemented into the diets of 240 nursery pigs for 42 d,and data related to performance were measured.Thereafter,the influence of EO on intestinal health,appetite and gut microbiota and their correlations were explored.EO supplementation increased(P<0.05)the body weight,average daily gain(ADG)and average daily feed intake(ADFI)of piglets,and reduced(P<0.05)diarrhea rates in nursery pigs.Furthermore,EO increased(P<0.05)the intestinal absorption area and the abundance of tight junction proteins,and decreased(P<0.05)intestinal permeability and local inflammation.In terms of intestinal development and the mucus barrier,EO promoted intestinal development and increased(P<0.05)the number of goblet cells.Additionally,we found that piglets in the EO-supplemented group had upregulated(P<0.05)levels of transporters and digestive enzymes in the intestine,which were significantly associated with daily gain and feed utilization.In addition,EO supplementation somewhat improved appetite in nursery pigs,increased the diversity of the gut microbiome and the abundance of beneficial bacteria,and there was a correlation between altered bacterial structure and appetite-related hormones.These findings indicate that EO is effective in promoting growth performance and nutrient absorption as well as in regulating appetite by improving intestinal health and bacterial structure.

Effects of different ratios of soluble to insoluble dietary fiber on growth performance and intestinal health of piglets

This study investigated the impact of different ratios of soluble to insoluble dietary fiber(SDF:IDF)formulations by sugar beet pulp(SBP)supplementation on piglet growth performance,nutrient digestibility,immune function,intestinal morphology,intestinal microbiota and intestinal health.A total of 60 crossbred piglets(Duroc×[Landrace×Yorkshire])at 40 d old with body weight of 10.0±0.3 kg were randomly assigned to 5 treatments with 6 replicates per treatment and 2 piglets per replicate in a 21-d trial.The dietary treatments included a corn-soybean meal diet(0%SBP supplementation;CON),and diets supplemented with 2%,4%,6%,and 8%SBP,representing different SDF:IDF ratios at 10.16%,13.53%,16.79%,19.86%,and 24.81%,respectively.The results indicated that the 8%SBP treatment had a negative effect on feed-to-gain ratio(linear,P=0.009)compared with the CON treatment(P=0.021).The apparent total tract digestibility(ATTD)of crude protein was lower in treatments supplemented with SBP(P=0.002)and showed a linear decrease(P=0.001),while the ATTD of IDF showed a linear increase(P=0.037)in four SBP treatments compared to the CON treatment.The 4%SBP treatment increased serum concentrations of triglyceride(quadratic,P=0.019)and K(linear,P<0.0037),and decreased alanine transaminase concentration(quadratic,P=0.015)compared with the CON treatment.The concentrations of Cit,Cys,Ile,Leu,Orn,Arg,taurine,urea,1-methylhistidine,α-aminoadipic acid,α-aminobutyric acid and cystathionine in the 4%SBP treatment were highest among all treatments(P<0.05).The serum concentrations of interleukin-6,interleukin-8,interleukin-10,transforming growth factor-β,and tumor necrosis factor-αin the 6%SBP treatment were higher than those in the CON treatment(P<0.05),which also increased mucin-2 and G protein-coupled receptor 41 mRNA expression(P<0.05)in colonic mucosa compared with the CON treatment and improved the intestinal barrier function.Diets containing more than 19.86%SDF:IDF could impair the intestinal health in piglets when SBP was used as the SDF source.Supplementing nursery piglet diets with 16.79%to 19.86%SDF:IDF is recommended for improving intestinal barrier function,increasing short-chain fatty acids concentrations,and improving intestinal microbiota composition.

Exopolysaccharides from lactic acid bacteria,as an alternative to antibiotics,on regulation of intestinal health and the immune system

Over-use or misuse of antibiotics in livestock and poultry production contributes to the rising threat of antibiotic resistance in animals and has negative ecological effects.Exopolysaccharides from lactic acid bacteria(LAB-EPS)are a class of biological macromolecules which are secreted by lactic acid bacteria to the outside of the cell wall during their growth and metabolism.Numerous studies demonstrated that LAB-EPS have anti-inflammatory and antimicrobial activities and are able to regulate intestinal health and the immune system in livestock.They are biodegradable,nontoxic and bio-compatible,which are considered as ideal alternatives to antibiotics.This review aims to discuss and summarize recent research findings of LAB-EPS on regulation of intestinal health and the immune system in animals,and thus provide scientific justification for commercial applications of LAB-EPS in livestock.

Dietary Litsea cubeba essential oil supplementation improves growth performance and intestinal health of weaned piglets

This paper was to determine the effects of dietary Litsea cubeba essential oil(LEO)supplementation on growth performance,immune function,antioxidant level,intestinal morphology and microbial composition in weaned piglets.One hundred and ninety-two piglets(Duroc×[Large White×Landrace])with 6.85±0.22 kg mean body weight weaned at 21 d of age were randomly assigned to 4 treatment groups with 8 replicates and were fed with a basal diet(CON)or CON diet containing 100(LLEO),200(MLEO)and 400(HLEO)mg/kg LEO.The results revealed that HLEO supplementation(P<0.05)increased the average daily gain on d 28 compared with CON.MLEO and HLEO supplementation decreased(P<0.05)feed conversion ratio.LEO-containing diets had a lower(P<0.05)diarrhea rate.Supple-mentation with HLEO increased(P<0.05)total antioxidant capacity(T-AOC)both in the serum and liver.Meanwhile,the supplementation of MLEO and HLEO resulted in higher(P<0.05)glutathione peroxidase(GPx)activities both in serum and liver.Supplementation of HLEO increased(P<0.05)serum immu-noglobulin A,immunoglobulin G and interleukin-10,whereas supplementation with MLEO and HLEO decreased(P<0.05)tumor necrosis factor-α.Villus height in the duodenum or jejunum was increased(P<0.05)in the HLEO group,and the villus height to crypt depth ratio in the jejunum was also improved(P<0.05)in the MLEO group.The addition of LEO increased(P<0.05)the richness and diversity of the microbial community in the cecum,which mainly increased the relative abundance of Oscillospir-aceae_UCG-005,Faecalibacterium,Blautia and Coprococcus.Piglets supplemented with HLEO increased(P<0.05)the concentration of short chain fatty acids(SCFA),including acetic acid in the cecum and propionic acid in the colon.In conclusion,these findings indicated that LEO supplementation improved growth performance and intestinal health in weaned piglets.

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.

Efficacy of soy protein concentrate replacing animal protein supplements in mucosa-associated microbiota, intestinal health, and growth performance of nursery pigs

This study investigated the effects of using soy protein concentrate (SPC) to replace animal protein supplements on mucosa-associated microbiota,intestinal health,and growth performance of nursery pigs.Fifty-six newly weaned pigs (BW=6.4±0.6 kg) were allotted to 5 treatments in a randomized complete block design.Pigs were fed for 35 d in 3 phases (P;1,2,3) for 10,12,13 d,respectively.Dietary treatments were:(1) basal diet with fish meal (P1:4%,P2:2%,and P3:1%),poultry meal (P1:10%,P2:8%,and P3:4%),and blood plasma (P1:4%,P2:2%,and P3:1%),where SPC replacing none (NC);(2) basal diet with SPC replacing fish meal (RFM);(3) basal diet with SPC replacing poultry meal (RPM);(4) basal diet with SPC replacing blood plasma (RBP);and (5) basal diet with SPC replacing all animal protein supplements (PC).Growth performance was recorded for each phase.Pigs were euthanized on d 35 to collect jejunal mucosa and tissue to evaluate intestinal health and microbiota,and ileal digesta to measure apparent ileal digestibility (AID) of nutrients.Data were analyzed using the MIXED procedure of SAS.Overall,RFM,RPM,and RBP did not affect growth performance,whereas PC decreased (P<0.05) ADG and ADFI.The RPM increased (P<0.05) Prevotella stercorea and decreased (P<0.05) Helicobacter rappini.The PC decreased (P<0.05) H.rappini,whilst increasing (P<0.05) Prevotella copri,Propionibacterium acnes,and Pelomonas aquatica.The RFM tended to increase (P=0.096) immunoglobulin A in the jejunum.The PC tended to decrease (P=0.078) jejunal crypt cell proliferation.There were no differences in the villus height,AID of nutrients,intestinal inflammation,and intestinal oxidative stress among treatments.In conclusion,SPC can replace fish meal,poultry meal,or blood plasma individually without affecting growth performance and intestinal health,and AID of nutrients of nursery pigs.Particularly SPC replacing poultry meal benefitted intestinal health by reducing H.rappini and increasing P.stercorea.However,SPC replacing all three animal protein supplements reduced growth of nursery pigs mainly by reducing feed intake.

Dietary methionine sources and levels modulate the intestinal health status of broiler chickens

Given the key role of methionine in biological processes,adequate methionine should be provided to meet the nutritional requirements.DL-2-hydroxy-4-(methylthio)-butanoic acid(DL-HMTBA)has been considered as an important source of methionine.However,the effects of different sources and levels of methionine on the intestinal health status have not been clarified yet.An experiment was carried out to investigate the effects of different dietary sources and levels of methionine on the intestinal epithelial barrier,inflammatory cytokines expression,ileal morphology,microbiota composition,and cecal short chain fatty acids(SCFA)profiles.For this purpose,720 male Arbor Acre broiler chicks at 1 d old were randomly assigned to a 2×3 factorial arrangement with 2 methionine sources(DL-methionine and DLHMTBA)and 3 total sulfur amino acids(TSAA)levels(80%,100%,and 120%of Arbor Acre recommendation).The results showed that DL-HMTBA supplementation promoted intestinal physical barrier at both gene expression level of claudin-1 and serum diamine oxidase level(P<0.05),and the inflammatory cytokine IL-6 m RNA expression was down-regulated by dietary DL-HMTBA supplementation compared with the DL-methionine group(P<0.05).Meanwhile,an upregulated gene expression of claudin-1 and zonula occluden-1(ZO-1)were observed in the low-TSAA treatment on d 14(P<0.05),whereas this treatment increased the expression of IL-1βand IL-6(P<0.05).Villus height to crypt depth ratio was high(P<0.05)in the middle-level TSAA group.Furthermore,DL-HMTBA supplementation optimized the microbiota of the ileum especially the relative abundance of Lactobacillus,where the digestion and absorption were completed,and elevated the concentrations of SCFA(acetate,propionate,and butyrate)in the cecal content on d 21(P<0.01).In conclusion,dietary DL-HMTBA supplementation improved the intestinal barrier function,immune homeostasis and optimized the microbiota to promote intestinal health status in broiler chickens.