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.

粉砂地层长距离大断面矩形顶管减阻技术研究

依托苏州市城北路大断面矩形顶管工程,通过对管-浆-土摩擦机理和顶推力影响因素进行研究,分析了管-浆-土相互组合作用下的5种模型,预测了5种模型下的顶推力,与实际施工中顶推力随顶进里程拟合结果进行了对比验证。结果表明:五种模型中,具有拱效应的情况下顶推力大小明显小于无拱效应情况;管土全接触模型顶推力大于任何其他计算模型,管浆全接触模型顶推力是五种预测模型中最小的。因此在管节周围注入浆液,可明显降低摩阻力。对于穿越粉砂地层大断面矩形顶管可采用“浓泥”进行注浆。中继间的使用对长距离矩形顶管顶进可分段减小主顶压力,避免施工过程中顶推力的急剧上升。

Effects of dietary protein/energy ratio on growth performance,carcass trait,meat quality,and plasma metabolites in pigs of different genotypes

Background： The protein/energy ratio is important for the production performance and utilization of available feed resources by animals. Increased protein consumption by mammals leads to elevated feed costs and increased nitrogen release into the environment. This study aimed to evaluate the effects of dietary protein/energy ratio on the growth performance, carcass traits, meat quality, and plasma metabolites of pigs of different genotypes. Methods： Bama mini-pigs and Landrace pigs were randomly assigned to two dietary treatment groups （Chinese conventional diet with low protein/energy ratio or National Research Council diet with high protein/energy ratio; n = 24 per treatment） in a 2 x 2 factorial arrangement. Blood and muscle samples were collected at the end of the nursery, growing, and finishing phases. Results： We observed significant interactions （P 〈 0.05） between breed and diet for total fat percentage, intramuscular fat （IMF） content, protein content in biceps femoris （BF） muscle, and plasma urea nitrogen （UN） concentration in the nursery phase; for average daily gain （ADG）, average daily feed intake （ADFI）, dry matter, IMF content in psoas major （PM） muscle, and plasma total protein and albumin concentrations in the growing phase; and for drip loss and plasma UN concentration in the finishing phase. Breed influenced （P 〈 0.05） growth performance, carcass traits, and meat quality, but not plasma metabolites. Throughout the trial, Landrace pigs showed significantly higher （P 〈 0.0_5） ADG, ADFI, dressing percentage, lean mass rate, and loin-eye area than did Bama mini-pigs, but significantly lower （P 〈 0.0.5） feed/gain ratio, fat percentage, backfat thickness, and IMF content. Dietary protein/energy ratio influenced the pH value, chemical composition of BF and PM muscles, and plasma activities of glutamic-pyruvic transaminase and gamma-glutamyl transpeptidase, and plasma concentration of UN. Conclusions： Compared with Landrace pigs, Bama mini-pigs showed slower growth and lower carcass performance, but had better meat quality. Moreover, unlike Landrace pigs, the dietary protein/energy ratio did not affect the growth performance of Bama mini-pigs. These results suggest that, in swine production, low dietary protein/energy ratio may be useful for reducing feed costs and minimizing the adverse effects of ammonia release into the environment.

Maternal supply of cysteamine alleviates oxidative stress and enhances angiogenesis in porcine placenta

Background:Oxidative stress in placenta is associated with the occurrence of adverse pregnancy outcomes in sow,but there are few satisfactory treatment strategies for these conditions.This study investigated the potential of cysteamine(CS)as an antioxidant protectant for regulating the reproductive performance,redox status,and placental angiogenesis of sows.Methods:The placental oxidative stress status and vascular density of piglets with different birth weights:<1.0 kg(low birth weight,LBW)and 1.4–1.6 kg(normal birth weight,NBW)were evaluated,followed by allotting 84 sows to four treatments(n=21)and feeding them with a basal diet supplemented with 0,100,300,or 500 mg/kg of CS from d 85 of gestation to d 21 of lactation,respectively.Placenta,serum,and colostrum samples of sows or piglets were collected,and the characteristics of sows and piglets were recorded.Furthermore,the in vivo results were validated using porcine vascular endothelial cells(PVECs).Results:Compared with the NBW placentae,the LBW placentae showed increased oxidative damage and were vulnerable to angiogenesis impairment.Particularly,H2O2-induced oxidative stress prompted intracellular reactive oxygen species generation and inhibited the tube formation and migration of PVECs as well as the expression of vascular endothelial growth factor-A(VEGF-A)in vitro.However,dietary CS supplementation can alleviate oxidative stress and improve the reproductive performance of sows.Specifically,compared with the control group,dietary 100 mg/kg CS could(1)decrease the stillbirth and invalid rates,and increase both the piglet birth weight in the low yield sows and the placental efficiency;(2)increase glutathione and reduce malondialdehyde in both the serum and the colostrum of sows;(3)increase the levels of total antioxidant capacity and glutathione in LBW placentae;(4)increase the vascular density,the mRNA level of VEGF-A,and the immune-staining intensity of platelet endothelial cell adhesion molecule-1 in the LBW placentae.Furthermore,the in vitro experiment indicated that CS pre-treatment could significantly reverse the NADPH oxidase 2-ROS-mediated inactivation of signal transducer and activator of transcription-3(Stat3)signaling pathway induced by H2O2 inhibition of the proliferation,tube formation,and migration of PVECs.Meanwhile,inhibition of Stat3 significantly decreased the cell viability,tube formation and the VEGF-A protein level in CS pretreated with H_(2)O_(2)-cultured PVECs.Conclusions:The results indicated that oxidative stress and impaired angiogenesis might contribute to the occurrence of LBW piglets during pregnancy,but CS supplementation at 100 mg/kg during late gestation and lactation of sows could alleviate oxidative stress and enhance angiogenesis in placenta,thereby increasing birth weight in low yield sows and reducing stillbirth rate.The in vitro data showed that the underlying mechanism for the positive effects of CS might be related to the activation of Stat3 in PVECs.

A review of the amino acid metabolism in placental function response to fetal loss and low birth weight in pigs

The fertility of sows mainly depends on the embryo losses during gestation and the survival rate of the postfarrowing piglets.The selection of highly-prolific sows has been mainly focused on the selection of genotypes with high ovulatory quota.However,in the early-and post-implantation stages,the rate of embryo losses was increased with the increase of zygotes.Among the various factors,placental growth and development is the vital determinant for fetal survival,growth,and development.Despite the potential survival of fetuses with deficient placental development,their life-conditions and growth can be damaged by a process termed intrauterine growth retardation(IUGR).The newborn piglets affected by IUGR are prone to increased morbidity and mortality rates;meanwhile,the growth,health and welfare of the surviving piglets will remain hampered by these conditions,with a tendency to exacerbate with age.Functional amino acids such as glycine,proline,and arginine continue to increase with the development of placenta,which are not only essential to placental growth(including vascular growth)and development,but can also be used as substrates for the production of glutathione,polyamines and nitric oxide to benefit placental function in many ways.However,the exact regulation mechanism of these amino acids in placental function has not yet been clarified.In this review,we provide evidence from literature and our own work for the role and mechanism of dietary functional amino acids during pregnancy in regulating the placental functional response to fetal loss and birth weight of piglets.This review will provide novel insights into the response of nutritionally nonessential amino acids(glycine and proline)to placental development as well as feasible strategies to enhance the fertility of sows.

Dietary supplementation with betaine or glycine improves the carcass trait,meat quality and lipid metabolism of finishing mini-pigs

The objective of the study is to evaluate and compare the effects of betaine or glycine on carcass trait,meat quality and lipid metabolism of finishing Huan Jiang mini-pigs.Betaine called trimethylglycine is a methyl derivative of glycine,but few researches were conducted to compare the impact of dietary betaine and glycine on pigs.One hundred and forty-four Huan Jiang mini-pigs(body weight=10.55±0.15 kg;70 d)were randomly divided to 3 treatment groups(basal diet,glycine or betaine).Results indicated that dietary betaine increased the average daily gain(ADG)and final weight(P<0.05).Dietary glycine or betaine markedly reduced average backfat thickness(P<0.05)and heightened lean percentage(P<0.01)compared to the control group.Moreover,in comparison with the control group,betaine significantly improved the redness(a*)and tenderness(shear force)of the longissimus dorsi(LD)muscle(P<0.05),whereas glycine only raised the value of a*of the LD muscle(P<0.05).These results showed that diet supplemented with 0.25%betaine and equimolar amounts of glycine could regulate cascass trait and meat quality of finishing Huan Jiang mini-pigs,and the effect of betaine was superior to that of glycine.

BAK1 plays contrasting roles in regulating abscisic acid-induced stomatal closure and abscisic acid-inhibited primary root growth in Arabidopsis

The mechanisms that balance plant growth and stress responses are poorly understood, but they appear to involve abscisic acid(ABA) signaling mediated by protein kinases. Here, to explore these mechanisms, we examined the responses of Arabidopsis thaliana protein kinase mutants to ABA treatment. We found that mutants of BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED RECEPTOR KINASE 1(BAK1) were hypersensitive to the effects of ABA on both seed germination and primary root growth. The kinase OPEN STOMATA 1(OST1) was more highly activated by ABA in bak1 mutant than the wild type. BAK1 was not activated by ABA treatment in the dominant negative mutant abi1-1 or the pyr1 pyl4 pyl5 pyl8 quadruple mutant, but it was more highly activated by this treatment in the abi1-2 abi2-2 hab1-1 loss-of-function triple mutant than the wild type. BAK1 phosphorylates OST1 T146 and inhibits its activity. Genetic analyses suggested that BAK1 acts at or upstream of core components in the ABA signaling pathway, including PYLs, PP2 Cs,and Sn RK2 s, during seed germination and primary root growth. Although the upstream brassinosteroid(BR) signaling components BAK1 and BR INSENSITIVE 1(BRI1) positively regulate ABAinduced stomatal closure, mutations affecting downstream components of BR signaling, including BRASSINOSTEROID-SIGNALING KINASEs(BSKs)and BRASSINOSTEROID-INSENSITIVE 2(BIN2), did not affect ABA-mediated stomatal movement. Thus,our study uncovered an important role of BAK1 in negatively regulating ABA signaling during seed germination and primary root growth, but positively modulating ABA-induced stomatal closure, thus optimizing the plant growth under drought stress.

Abscisic acid signaling negatively regulates nitrate uptake via phosphorylation of NRT1.1 by SnRK2s in Arabidopsis

Nitrogen(N)is a limiting nutrient for plant growth and productivity.The phytohormone abscisic acid(ABA)has been suggested to play a vital role in nitrate uptake in fluctuating N environments.However,the molecular mechanisms underlying the involvement of ABA in N deficiency responses are largely unknown.In this study,we demonstrated that ABA signaling components,particularly the three subclass Ⅲ SUCROSE NON-FERMENTING1(SNF1)-RELATED PROTEIN KINASE 2 S(SnRK2)proteins,function in root foraging and uptake of nitrate under N deficiency in Arabidopsis thaliana.The snrk2.2 snrk2.3 snrk2.6 triple mutant grew a longer primary root and had a higher rate of nitrate influx and accumulation compared with wild-type plants under nitrate deficiency.Strikingly,SnRK2.2/2.3/2.6 proteins interacted with and phosphorylated the nitrate transceptor NITRATE TRANSPORTER1.1(NRT1.1)in vitro and in vivo.The phosphorylation of NRT1.1 by SnRK2 s resulted in a significant decrease of nitrate uptake and impairment of root growth.Moreover,we identified NRT1.1Ser585 as a previously unknown functional site:the phosphomimetic NRT1.1S585 D was impaired in both low-and high-affinity transport activities.Taken together,our findings provide new insight into how plants fine-tune growth via ABA signaling under N deficiency.

Compensation effects of coated cysteamine on meat quality, amino acid composition, fatty acid composition, mineral content in dorsal muscle and serum biochemical indices in finishing pigs offered reduced trace minerals diet

Dear Editor.Trace mineral elements(ME)and amino acids have been demonstrated to be essential bioelements in animal nutrition.If there is a deficiency in ME,a number of biological functions in animals may be affected,including physical growth,psychomotor development,and immunity.Supplementation of pig diets with ME is known to improve the animals'growth,reproduction,and their immunity against oxidative stress and cell damage.

Imbalanced dietary methionine-to-sulfur amino acid ratio can affect amino acid profiles, antioxidant capacity, and intestinal morphology of piglets

Animal protein sources such as fishmeal and plasma powder are excellent and indispensable sources of energy,amino acid s,and minerals in animal production.Amino acid imbalance,especially methionine-to-sulfur amino acid(Met:SAA)ratio,caused by an imbalance of animal protein meal leads to growth restriction.This study was conducted to evaluate the effects of imbalanced Met:SAA ratio supplementation of different animal protein source diets on growth performance,plasma amino acid profiles,antioxidant capacity and intestinal morphology in a piglet model.Twenty-four weaned piglets(castrated males;BW=10.46±0.34 kg),assigned randomly into 3 groups(8 piglets/group),were fed for 28 d.Three experimental diets of equal energy and crude protein levels were as follows:1)a corn-soybean basal diet with a Met:SAA ratio at 0.51(BD);2)a plasma powder diet with a low Met:SAA ratio at 0.41(L-MR);3)a fishmeal diet with a high Met:SAA ratio at0.61(H-MR).Results revealed that compared to BD,L-MR significantly decreased(P<0.05)the activities of plasma total antioxidant capacity and glutathione peroxidase,plasma amino acid profiles,and significantly reduced(P<0.05)villus height and crypt depth in the duodenum and jejunum.Additionally,L-MR significantly reduced(P<0.05)the mRNA expression level of solute carrier family 7 member 9(SIC7 A9)in the ileum,and significantly increased(P<0.05)mRNA expression levels of zonula occludens-1(ZO-1)in the duodenum,and Claudin-1,ZO-1,sodium-coupled neutral amino acid transporters 2(SNAT2)and SIC7 A7 in the j ejunum.HMR significantly increased(P<0.05)plasma SAA levels,and significantly reduced(P<0.05)average daily feed intake,villus height,and villus height-to-crypt depth(VH:CD)ratio in the ileum compared to BD.In conclusion,L-MR may result in oxidative stress and villous atrophy but proves beneficial in improving intestinal barrier function and the activity of amino acid transporters for compensatory growth.H-MR may impair intestinal growth and development for weaned piglets.The research provides a guidance on the adequate Met:SAA ratio(0.51)supplementation in diet structure for weaned piglets.

Ca^(2+)-dependent successive phosphorylation of vacuolar transporter MTP8 by CBL2/3-CIPK3/9/26 and CPK5 is critical for manganese homeostasis in Arabidopsis

Manganese(Mn)is an essential micronutrient for all living organisms.However,excess Mn supply that can occur in acid or waterlogged soils has toxic effects on plant physiology and development.Although a variety of Mn transporter families have been characterized,we have only a rudimentary understanding of how these transporters are regulated to uphold and adjust Mn homeostasis in plants.Here,we demonstrate that two calcineurin-B-like proteins,CBL2/3,and their interacting kinases,CIPK3/9/26,are key regulators of plant Mn homeostasis.Arabidopsis mutants lacking CBL2 and 3 or their interacting protein kinases CIPK3/9/26 exhibit remarkably high Mn tolerance.Intriguingly,CIPK3/9/26 interact with and phosphorylate the tonoplast-localized Mn and iron(Fe)transporter MTP8 primarily at Ser35,which is conserved among MTP8 proteins from various species.Mn transport complementation assays in yeast combined with multiple physiological assays indicate that CBL-CIPK-mediated phosphorylation of MTP8 negatively regulates its transport activity from the cytoplasm to the vacuole.Moreover,we show that sequential phosphorylation of MTP8,initially at Ser31/32 by the calcium-dependent protein kinase CPK5 and subsequently at Ser35 by CIPK26,provides an activation/deactivation fine-tuning mechanism for differential regulation of Mn transport.Collectively,our findings define a two-tiered calcium-controlled mechanism for dynamic regulation of Mn homeostasis under conditions of fluctuating Mn supply.

Inclusion of wheat aleurone in gestation diets improves postprandial satiety,stress status and stillbirth rate of sows

This study investigated the effects of different amounts of wheat aleurone(WA)(0,15%,30%)inclusion in gestation diets on the reproductive performance,postprandial satiety,stress status and stereotypic be-haviors of sows.A total of 84 Landrace×Yorkshire sows(parity 4.87±1.32)at breeding were randomly allotted to one of the three isoenergetic and isonitrogenous dietary treatments based on parity and body weight.The results showed that,compared with the control(0),sows fed the WA diet had a higher serum concentration of peptide YY(PYY)(P<0.05)and glucagon like peptide-1(GLP-1)(P<0.05)and a lower concentration of saliva cortisol(P<0.01).Importantly,compared with the control group,only the 15%WA group had a higher concentration of the total antioxidant capacity(T-AOC)(P<0.05),lower pro-portions of sitting(P=0.05)and stillbirth rates(P<0.01).Accordingly,the production cost per piglet born alive($6.9 vs.$7.6)or per piglet born healthy($7.4 vs.$7.9)declined in the 15%WA group versus the control group.Overall,15%WA inclusion in gestation diets contributed to enhancing postprandial satiety,alleviating stress status and decreasing stillbirth rate of sows.This study provides a reference for the application of WA as a partial substitute for conventional feed ingredients to improve sows'repro-ductive performance.

Effects of dietary supplementation of nucleotides from late gestation to lactation on the performance and oxidative stress status of sows and their offspring

Increased metabolic burdens in breeding sows,which are induced by elevated systemic oxidative stress,could increase the need for nucleotides to repair lymphocyte DNA damage;however,de novo synthesis of nucleotides may be insufficient to cover this increased need.This study investigated the effects of dietary nucleotides on milk composition,oxidative stress status,and the reproductive and lactational performance of sows.Forty multiparous sows were assigned to 2 dietary treatments(Control group,and 1 g/kg Nucleotides group)based on a randomized complete block design using their BW at 85 d of gestation as a block.Sows from 2 groups were fed a restricted diet during gestation and ad libitum during lactation.The experiment lasted from 85 d of gestation to 21 d of lactation.The reproductive perfor-mance of sows and the growth performance of suckling piglets were measured.Oxidative stress pa-rameters and milk components were also analysed.Data were analyzed using contrasts in the MIXED procedure of SAS.Sows in the Nucleotides group consumed more feed during the first week(P<0.01)and from 1 to 21 d(P<0.05)of lactation than those in Control group.Correspondingly,the litter weight gain of piglets showed a tendency to increase from cross-fostering to 9 d(P=0.09)and from cross-fostering to 20 d(P=0.10)in the Nucleotides group relative to the Control group.Additionally,the Nucleotides group was higher(P<0.01)than the Control group in the concentrations of uridine 5'monophosphate,guanosine 5'monophosphate,inosine 5'monophosphate,adenosine 5'mono-phosphate and total nucleotides in milk.Furthermore,the Nucleotides group was higher(P<0.01)than the Control group in the serum levels of total antioxidant capacity(P<0.01)for sows at 109 d of gestation and glutathione peroxidase for weaning piglets,but lower at the levels of thiobarbituric acid-reactive substances(P<0.05)in serum of weaning piglets.This study indicated that maternal dietary nucleotides could promote piglet growth,probably due to the higher lactational feed intake and higher concentration of nucleotides in the milk of sows,and lower oxidative stress for both sows and piglets.