Regulation of oxidative stress in the intestine of piglets after enterotoxigenic Escherichia coli (ETEC) infection.

Enterotoxigenic Escherichia coli (ETEC) is recognized globally as a major gastrointestinal pathogen that impairs intestinal function. ETEC infection can lead to oxidative stress and disruption of intestinal integrity. The present study investigated the mechanism of increased oxidative stress and whether restoration of antioxidant defense could improve intestinal integrity in a piglet model with ETEC infection. Weaned piglets were divided into three groups: control, ETEC-infection and ETEC-infection with antibiotic supplementation. The infection caused a significant elevation of serum diamine oxidase activity and D-lactate levels coupled with a reduced intestinal (mid-jejunum) tight-junction protein expression, suggesting increased intestinal permeability and impaired gut function. The infection also inhibited nuclear factor erythroid 2-related factor 2 (Nrf2) activation, decreased the expression of glutathione synthesizing enzymes, superoxide dismutase-1 (SOD1), and heme oxygenase-1 (HO-1) in the intestine. This led to a decreased antioxidant glutathione level and an increased lipid peroxidation in the intestine and serum, indicating oxidative stress. The infection stimulated the expression of pro-inflammatory cytokines (IL-6, TNF-α). Antibiotic supplementation attenuated oxidative stress, in part, through restoration of glutathione levels and antioxidant enzyme expression in the intestine. Such a treatment enhanced tight-junction protein expression and improved intestinal function. Furthermore, induction of oxidative stress in Caco2 cells by hydrogen peroxide inhibited tight-junction protein expression and stimulated inflammatory cytokine expression. Glutathione supplementation effectively attenuated oxidative stress and restored tight-junction protein expression. These results suggest that downregulation of Nrf2 activation may weaken antioxidant defense and increase oxidative stress in the intestine. Mitigation of oxidative stress can improve intestinal function after infection.

Functional evaluation of Bacillus licheniformis PF9 for its potential in controlling enterotoxigenic Escherichia coli in weaned piglets.

During the bacterial selection, isolate PF9 demonstrated tolerance to low pH and high bile salt and an ability to extend the lifespan of Caenorhabditis elegans infected with enterotoxigenic Escherichia coli (ETEC; P < 0.05). Thirty-two weaned piglets susceptible to ETEC F4 were randomly allocated to four treatments as follows: 1) non-challenged negative control group (NNC; basal diet and piglets gavaged with phosphate-buffered saline), 2) negative control group (NC; basal diet and piglets challenged with ETEC F4, 3 × 107 CFU per pig), 3) positive control (PC; basal diet + 80 mg·kg-1 of avilamycin and piglets challenged with ETEC F4), and 4) probiotic candidate (PF9; control basal diet + 2.5 × 109 CFU·kg-1 diet of B. licheniformis PF9 and piglets challenged with ETEC F4). The infection of ETEC F4 decreased average daily gain and gain:feed in the NC group when compared to the NNC group (P < 0.05). The inoculation of ETEC F4 induced severe diarrhea at 3 h postinoculum (hpi), 36, 40 hpi in the NC group when compared to the NNC group (P < 0.05). The supplementation of B. licheniformis PF9 significantly relieved diarrhea severity at 3 hpi when compared to the NC group (P < 0.05). The inoculation of ETEC F4 reduced duodenal, jejunal, and ileal villus height (VH) in the NC group when compared to the NNC group. A significant (P < 0.05) decrease was detected in the duodenal VH in the PC and NNC groups. Moreover, the NNC group had a reduced relative mRNA level of Na+-glucose cotransporter 1 (SGLT1) when compared to the NC group (P < 0.05). Compared to the NC and NNC groups, the supplementation of B. licheniformis PF9 increased the relative mRNA levels of aminopeptidase N, occludin, zonula occludens-1, and SGLT1 (P < 0.05). The supplementation of B. licheniformis PF9 also significantly increased the relative mRNA level of excitatory amino acid transporter 1 when compared to the NC group (P < 0.05). Piglets supplemented with B. licheniformis PF9 showed lower relative abundance of Bacteroidetes in the colon than piglets from the NNC group (P < 0.05). The NNC group had a higher relative abundance of Firmicutes in the ileum than all the challenged piglets (P < 0.05); however, a lower relative abundance of Proteobacteria in the ileum and colon was observed in the NC group (P < 0.05). This study provides evidence that B. licheniformis PF9 has the potential to improve the gut health of piglets under challenging conditions.

The relative age effect and its influence on athletic performance in Chinese junior female' tennis players.

The relative age effect (RAE) has been the focus of numerous studies; however, there are still fewer studies in women's sports than in men's sports. In this study, all female players (N = 2,255) who participated in Chinese junior tennis competitions (U12, U14, U16, and the National Junior Team) from 2014 to 2019 were investigated in terms of competitors' birth dates and year-end rankings. For the purposes of the analysis, the birth dates were also separated into quarters and half years. The study's objectives were to analyze the prevalence of the RAE among young Chinese female tennis players and to further examine how the RAE affects athletic performance. Differences between the observed and expected distributions of birth dates were tested using the chi-square statistic, and subsequent calculations were tested using odds ratios. The RAE was discovered to be present in every group of Chinese junior female tennis players (p < 0.001), with the proportions of those born in the first half of the year being 56.4% (U12), 53.1% (U14), and 57.0% (U16), respectively. The RAE for athletes selected for the National Women's Junior Tennis Team was even more significant, with the percentage of birth dates in the first half of the year at 61.2%. Finally, we observed a tendency for the effect of the RAE on the athletic performance of adolescent female tennis players to diminish with age.

Rapid discrimination of urine specific gravity using spectroscopy and a modified combination method based on SPA and spectral index.

To achieve high-accuracy urine specific gravity discrimination and guide the design of four-waveband multispectral sensors. A modified combination strategy was attempted to be proposed based on the successive projections algorithm (SPA) and the spectral index (SI) in the present study. First, the SPA was used to select four spectral variables in the full spectra. Second, the four spectral variables were mathematically transformed by SI to obtain SI values. Then, SPA gradually fusions the SI values and establishes models to identify USG. The results showed that the SPA can screen out the four characteristic wavelengths related to the measured sample attributes. SIs can be used to improve the performance of constructed prediction models. The best model only involves four spectral variables and 1 SI value, with high accuracy (91.62%), sensitivity (0.9051), and specificity (0.9667). The results reveal that m-SPA-SI can effectively distinguish USG and provide design guidance for 4-wavelength multispectral sensors.

A Triplet Iron Carbyne Complex.

Tuning the spin state of metal carbynes, which have broad applications in organic synthesis and material science, presents a formidable challenge for modern chemists as the strong field nature of carbyne ligands dictates low-spin ground spin states (S = 0 or 1/2) for known metal carbynes. Through the oxidative addition reaction of a low-coordinate iron(0) N-heterocyclic carbene complex with the C-S bond of a thioazole-2-ylidene, we synthesized the first triplet (S = 1) metal terminal carbyne, an iron cyclic carbyne complex. Different from the classical metal carbynes, the triplet complex features an LXZ-type carbyne ligand and a weak Fe≡C triple bond, which endow it with the unique reactivity pattern of facile carbyne coupling, weak affinity toward nucleophiles, and facial addition reactions with electrophiles.

The relative age effect among Chinese junior men's tennis players and its impact on sports performance.

The relative age effect (RAE) has been the subject of many studies, but no relevant literature has discussed the phenomenon of RAE in Chinese tennis. Numerous studies have demonstrated that RAE significantly contributes to brain drain and other occurrences that create inequity. This paper analyzes the birth dates and year-end rankings of all male players (N = 2697) who participated in China's junior tennis tournaments (U12, U14, U16) between 2014 and 2019 and who were selected for China's National Junior Team in 2019 and 2020; the paper classifies the birth dates into quarters and semesters. One of the research objectives of this study is to analyze whether RAE exists in Chinese junior men's tennis and whether RAE exerts an effect on athletes' performance. Differences between the observed and expected birthdate distributions were tested using chi-square statistics, and subsequent calculations were tested using odds ratios. The study found that RAE was present in all Chinese junior male tennis sports groups (p<0.001). The percentages of athletes born in the first half of the year were 56.4% (U12), 60.4% (U14), and 60.4% (U16), and the percentages of those born in the first quarter were 34.1% (U12), 36.4% (U14), and 37.1% (U16). Athletes with birth dates closer to the beginning of the year had a higher probability of achieving excellent athletic performance as a result of RAE, whereas those who were born near the end of the year had a more difficult time achieving strong athletic performance.

Integrated thrust ripple identification and compensation for linear servo system using an MP algorithm.

Generally there are two methods for the thrust ripple modeling: one is to identify the eigenvalues and the model parameters of thrust ripple sequentially under rigorous operating conditions; another is to treat thrust ripple as a general and inaccurate disturbance. To get rid of the constraints and further enhance the tracking accuracy of the linear servo system, a novel integrated identification and compensation scheme using an improved matching pursuit algorithm is proposed in this paper. First, the dynamics of the linear motor is formulated, and the cause of thrust ripple is analyzed. Then, a time-frequency atomic library of thrust ripple is constructed with the consideration of the frequency characteristics of position command, and meanwhile, the two optimal atoms are obtained successively by maximizing the inner product for the thrust ripple reconstruction. Based on the above, the eigenvalues and model parameters of thrust ripple can be simultaneously identified in an online manner. Finally, the feedforward compensation component is devised by the identification results to suppress thrust ripple. In order to verify the superiority of the proposed scheme, simulations and experiments are conducted compared with the conventional methods.

Acute Effects of Back Squat Combined with Different Elastic Band Resistance on Vertical Jump Performance in Collegiate Basketball Players.

The purpose of this study was to compare the acute effects of back squat exercise with or without elastic band on countermovement jump performance. Thirteen collegiate male basketball players (age: 20.5 ± 0.9 years; height: 188.5 ± 8.5 cm; body mass: 82.8 ± 12.9 kg) completed 5 familiarization and 4 experimental sessions separated by at least 48 hours. In the experimental sessions, the order of the conditions was randomized so that the participants performed 1 set of 3 repetitions of barbell back squat at 85% of their one-repetition maximum (1-RM), 1 set of 3 repetitions of back squat at 85% 1-RM with 20% variable resistance training (VRT), 30%VRT, or 40%VRT of the total load coming from the elastic band. Countermovement jump performance was assessed before (baseline), 30 seconds, 3 minutes, 6 minutes, and 9 minutes following each condition. Jump height, rate of force development, peak power, and vastus lateralis, vastus medialis, and medial gastrocnemius electromyography data were collected. Compared with the baseline, 30%VRT significantly improved jump height at 3 minutes post-exercise by 1.3 cm (P < 0.001) and 6 minutes post-exercise by 1.2 cm (P = 0.005); 40%VRT significantly improved jump height from 30 seconds up to the 9th minute (1.2 to 1.9 cm, P ≤ 0.036). The superior jump height was also accompanied by improved kinetic and electromyography data. No significant changes were observed in the barbell back squat and 20%VRT conditions. In conclusion, back squat at 85% 1-RM with 40% elastic band resistance led to superior vertical jump performance with an optimal time window of 3 minutes.

Phylogenetic Analysis of the PR-4 Gene Family in Euphorbiaceae and Its Expression Profiles in Tung Tree (Vernicia fordii).

Pathogenesis-related protein-4 (PR-4) is generally believed to be involved in physiological processes. However, a comprehensive investigation of this protein in tung tree (Vernicia fordii) has yet to be conducted. In this study, we identified 30 PR-4 genes in the genomes of Euphorbiaceae species and investigated their domain organization, evolution, promoter cis-elements, expression profiles, and expression profiles in the tung tree. Sequence and structural analyses indicated that VF16136 and VF16135 in the tung tree could be classified as belonging to Class II and I, respectively. Phylogenetic and Ka/Ks analyses revealed that Hevea brasiliensis exhibited a significantly expanded number of PR-4 genes. Additionally, the analysis of promoter cis-elements suggested that two VfPR-4 genes may play a role in the response to hormones and biotic and abiotic stress of tung trees. Furthermore, the expression patterns of VfPR-4 genes and their responses to 6-BA, salicylic acid, and silver nitrate in inflorescence buds of tung trees were evaluated using qRT-PCR. Notably, the expression of two VfPR-4 genes was found to be particularly high in leaves and early stages of tung seeds. These results suggest that VF16136 and VF16135 may have significant roles in the development of leaves and seeds in tung trees. Furthermore, these genes were found to be responsive to 6-BA, salicylic acid, and silver nitrate in the development of inflorescence buds. This research provides valuable insights for future investigation into the functions of PR-4 genes in tung trees.

Microencapsulation protected Lactobacillus viability and its activity in modulating the intestinal microbiota in newly weaned piglets.

Lactobacilli are sensitive to heat, which limits their application as probiotics in livestock production. Lactobacillus rhamnosus LB1 was previously shown to reduce enterotoxigenic Escherichia coli (ETEC) and Salmonella infections in pigs. To investigate its potential in the application, the bacterium was microencapsulated and examined for its survival from feed pelleting and long-term storage as well as its function in modulating pig intestinal microbiota. The in vitro studies showed that freshly microencapsulated Lactobacillus rhamnosus LB1 had viable counts of 9.03 ± 0.049 log10 colony-forming units/g, of which only 0.06 and 0.87 Log of viable counts were reduced after storage at 4 and 22 °C for 427 d. The viable counts of encapsulated Lactobacillus rhamnosus LB1 were 1.06 and 1.54 Log higher in the pelleted and mash feed, respectively, than the non-encapsulated form stored at 22 °C for 30 d. In the in vivo studies, 80 piglets (weaned at 21 d of age) were allocated to five dietary treatments for a 10-d growth trial. The dietary treatments were the basal diet (CTL) and basal diet combined with either non-encapsulated LB1 (NEP), encapsulated LB1 (EP), bovine colostrum (BC), or a combination of encapsulated LB1 and bovine colostrum (EP-BC). The results demonstrated that weaning depressed feed intake and reduced growth rates in pigs of all the treatments during 21 to 25 d of age; however, the body weight gain was improved during 25 to 31 d of age in all groups with the numerically highest increase in the EP-BC-fed pigs during 21 to 31 d of age. Dietary treatments with EP, particularly in combination with BC, modulated pig intestinal microbiota, including an increase in Lactobacillus relative abundance. These results suggest that microencapsulation can protect Lactobacillus rhamnosus LB1 against cell damage from a high temperature during processing and storage and there are possible complementary effects between EP and BC.

Both in vitro and in vivo studies were conducted to verify if the microencapsulation method reported previously could preserve the viability of Lactobacillus rhamnosus LB1 after feed pelleting and long-term storage, and the probiotic functions of the bacterium either alone or in combination with bovine colostrum (BC) in the weaning transition phase of piglets. The results demonstrated that microencapsulation protected Lactobacillus rhamnosus LB1 against cell damage from a high temperature during processing and storage. Dietary treatments with encapsulated LB1, particularly in combination with BC, modulated pig intestinal microbiota, including an increase in Lactobacillus relative abundance during the weaning transition.

Glutamine boosts intestinal stem cell-mediated small intestinal epithelial development during early weaning: Involvement of WNT signaling.

Early weaning usually causes small intestine epithelial development abnormality, increasing the risk of gastrointestinal diseases. Glutamine (Gln), enriching in plasma and milk, is widely reported to benefit intestinal health. However, whether Gln affects intestinal stem cell (ISC) activity in response to early weaning is unclear. Here, both the early weaning mice and intestinal organoids were used to study the role of Gln in regulating ISC activities. Results showed that Gln ameliorated early weaning-induced epithelial atrophy and augmented the ISC-mediated epithelial regeneration. Gln deprivation disabled ISC-mediated epithelial regeneration and crypt fission in vitro. Mechanistically, Gln augmented WNT signaling in a dose-dependent manner to regulate ISC activity, while WNT signaling blockage abolished the effects of Gln on ISCs. Together, Gln accelerates stem cell-mediated intestinal epithelial development associated with the augmentation of WNT signaling, which provides novel insights into the mechanism by which Gln promotes intestinal health.

Virulence potential of antimicrobial-resistant extraintestinal pathogenic Escherichia coli from retail poultry meat in a Caenorhabditis elegans model.

Healthy poultry can be a reservoir for extraintestinal pathogenic Escherichia coli (ExPEC), some of which could be multidrug resistant to antimicrobials. These ExPEC strains could contaminate the environment and/or food chain representing thus, food safety and human health risk. However, few studies have shown the virulence of poultry-source antimicrobial-resistant (AMR) ExPEC in humans. This study characterized AMR ExPEC and investigated the virulence potential of some of their isolates in a Caenorhabditis elegans infection model. A total of 46 E. coli isolates from poultry (chicken, n = 29; turkey, n = 12) retail meats and chicken feces (n = 4), or humans (n = 1) were sequenced and identified as ExPEC. Except eight, all remaining 38 ExPEC isolates were resistant to at least one antibiotic and carried corresponding antimicrobial resistance genes (ARGs). About 27 of the 46 ExPEC isolates were multidrug-resistant (≥3 antibiotic classes). Seven ExPEC isolates from chicken or turkey meats were of serotype O25:H4 and sequence type (ST) 131 which clustered with an isolate from a human urinary tract infection (UTI) case having the same serotype and ST. The C. elegans challenge model using eight of studied ExPEC isolates harboring various ARGs and virulence genes (VGs) showed that regardless of their ARG or VG numbers in tested poultry meat and feces, ExPEC significantly reduced the life span of the nematode (P < 0.05) similarly to a human UTI isolate. This study indicated the pathogenic potential of AMR ExPEC from retail poultry meat or feces, but more studies are warranted to establish their virulence in poultry and human. Furthermore, relationships between specific resistance profiles and/or VGs in these E. coli isolates for their pathogenicity deserve investigations.

Neural efficiency and proficiency adaptation of effective connectivity corresponding to early and advanced skill levels in athletes of racket sports.

This study explored how the neural efficiency and proficiency worked in athletes with different skill levels from the perspective of effective connectivity brain network in resting state. The deconvolved conditioned Granger causality (GC) analysis was applied to functional magnetic resonance imaging (fMRI) data of 35 elite athletes (EAs) and 42 student-athletes (SAs) of racket sports as well as 39 normal controls (NCs), to obtain the voxel-wised hemodynamic response function (HRF) parameters representing the functional segregation and effective connectivity representing the functional integration. The results showed decreased time-to-peak of HRF in the visual attention brain regions in the two athlete groups compared with NC and decreased response height in the advanced motor control brain regions in EA comparing to the nonelite groups, suggesting the neural efficiency represented by the regional HRF was different in early and advanced skill levels. GC analysis demonstrated that the GC values within the middle occipital gyrus had a linear trend from negative to positive, suggesting a stepwise "neural proficiency" of the effective connectivity from NC to SA then to EA. The GC values of the inter-lobe circuits in EA had the trend to regress to NC levels, in agreement with the neural efficiency of these circuits in EA. Further feature selection approach suggested the important role of the cerebral-brainstem GC circuit for discriminating EA. Our findings gave new insight into the complementary neural mechanisms in brain functional segregation and integration, which was associated with early and advanced skill levels in athletes of racket sports.

Comparative effects of dietary methionine and cysteine supplementation on redox status and intestinal integrity in immunologically challenged-weaned pigs.

Sulfur-containing amino acids such as methionine and cysteine play critical roles in immune system and redox status. A body of evidence shows that metabolic aspects of supplemented Met and Cys may differ in the body. Therefore, the study aimed to investigate the effects of dietary Met and Cys supplementation in immunologically challenged weaned pigs. Forty weaned piglets (6.5 ± 0.3 kg) were randomly allocated to five treatment groups. The treatment included: (1) sham-challenged control (SCC), (2) challenged control (CC), (3) MET (CC + 0.1% DL-Met), (4) CYS (CC + 0.1% L-Cys), and (5) MET + CYS (CC + 0.1% DL-Met + 0.1% L-Cys). On day 7, all pigs were intramuscularly injected with either Escherichia coli O55:B5 lipopolysaccharides (LPS) or phosphate-buffered saline. Blood, liver, and jejunum samples were analyzed for immune response and redox status. The CC group had lower (P < 0.05) villus surface area and higher (P < 0.05) flux of 4-kDa fluorescein isothiocyanate dextran (FD4) than the SCC group. A lower (P < 0.05) glutathione (GSH) concentration was observed in the jejunum of pigs in the CC group than those in the SCC group. Dietary Cys supplementation increased (P < 0.05) villus surface area, GSH levels, and reduced (P < 0.05) the flux of FD4 in the jejunum of LPS-challenged pigs. Dietary Met supplementation enhanced (P < 0.05) hepatic GSH content. Pigs challenged with LPS in the MET group had lower serum IL-8 concentration than those in the CC group. There was a Met × Cys interaction (P < 0.05) in serum IL-4 and IL-8 concentrations, and Trolox equivalent antioxidant capacity. Dietary L-Cys supplementation restored intestinal integrity and GSH levels that were damaged by lipopolysaccharides administration. Dietary DL-Met supplementation improved hepatic GSH and reduced systemic inflammatory response, but antagonistic interaction with dietary L-Cys supplementation was observed in the inflammatory response and redox status.

Signet-Ring-Shaped Octaphosphorus-Cobalt Complexes: Synthesis, Structure, and Functionalization Reactions with Carbene Analogs.

White phosphorus activation with low-valent metal species has proved to be very effective in converting P4 into small Pn-containing molecules with n ≤ 4. Much less developed are metal-mediated P4-coupling reactions that can yield selectively large polyphosphorus clusters. Herein, we report P4-activation reactions with three-coordinate N-heterocyclic carbene(NHC)-cobalt(0)-alkene complexes, which produce the P8 complexes of cobalt [(NHC)2Co2(µ-η6:η6-P8)] (NHC = 1,3-dimesitylimidazol-2-ylidene (IMes), 1; 1,3-bis(2,6-diethylphenyl)imidazol-2-ylidene (IDep), 2) in high yields. The P8 ligand in 1 and 2 exhibits a signet-ring type structure that was predicted by theoretical study but has never been obtained in synthetic molecules. Theoretical studies suggest that [(NHC)2Co2(µ-η6:η6-P8)] is best described as a Co0-[P8]0-Co0 complex featuring a Co-Co σ-bond and discernible Co-to-P8 back-donation. By treating with N-heterocyclic silylene, phosphinidene precursor, organic azides, and NHCs, complex 1 was transformed into [(IMes)2Co2(µ-η6:η6-P8X)] (X = 1,3-bis(tert-butyl)-1,3-diaza-2-silacyclopent-4-en-2-ylidene, 3; PNMe2, 4), [(IMes)2Co2(σ:(µ-η4:η6)-RNPPP6)] (R = SO2-C6H4-p-Me, 5; C(CF3)2Ph, 6), and [(IMes)2Co2(µ-η2:η2-cyclo-P4P(IPri2))(µ-η3:η3-P3)] (7), respectively. Complexes 3-7 can be viewed as the adducts of 1 with the corresponding carbene analogous SiR2, PR, NR, and CR2, but their core structures are distinct. Under similar conditions, white phosphorus is inert toward these reagents. These cage functionalization reactions showcase the enhanced reactivity of the P8 ligand in [(NHC)2Co2(µ-η6:η6-P8)] over that of P4, and indicate the amphiphilicity of the P8 ligand toward electrophiles and nucleophiles.

Effects of high- and low-fiber diets on intestinal oxidative stress in growing-finishing pigs.

Feed is the most expensive facet of commercial pork production. In order to reduce feed costs, using high-fiber ingredients has become a common practice. Moderate levels of fiber can maintain intestinal physiological function and promote intestinal health. Oxidative stress is linked to impaired nutrient absorption and growth performance. This study investigated the effects of high-fiber (5.26% crude fiber) and low-fiber (2.46% crude fiber) diets on growth performance and intestinal oxidative stress parameters in growing-finishing pigs. Forty growing pigs with initial body weight (27.07 ± 1.26 kg) were randomly assigned to 2 treatment groups with 10 replicates of 2 pigs per pen. Pigs were weighed on day 35, 42, and 70. The feed intake was recorded daily to calculate growth performance parameters. On day 70, eight pigs in each treatment group were randomly selected and euthanized to obtain jejunum to measure oxidative stress status. Pigs fed a high-fiber diet were heavier than those fed a low-fiber diet on days 35, 42, and 70 (P < 0.05). During the whole feeding period, pigs fed a high-fiber diet had a higher average daily gain than those fed a low-fiber diet (P < 0.05). The low-fiber diet resulted in increased levels of malondialdehyde (P < 0.05) in the jejunum, suggesting that the low-fiber diet contributed to oxidative stress in the jejunum. The low-fiber diet also led to a significant increase in glutathione and oxidized glutathione levels (P < 0.05) in the jejunum, indicating that pigs fed a low-fiber diet needed to produce more antioxidant substances to cope with oxidative stress in the intestine. This was accompanied by a significant increase in the expression of glutathione synthesizing enzymes in the jejunum of the low-fiber group (P < 0.05). These results suggest that the high-fiber diet can improve growth performance and maintain intestinal health in growing-finishing pigs by reducing intestinal oxidative stress.

The gastrointestinal tract provides the location for the digestion and absorption of nutrients. It has physical and chemical barriers to protect body from pathogens and toxins. Oxidative stress tends to weaken the physical and chemical barriers of the intestine, which in turn can lead to intestinal dysfunction. Fiber has been suggested to have beneficial effects on the intestine health of pigs. Revealing how fiber can maintain intestinal health is important for pig production. In the present research, we investigated the effect of fiber on the oxidative stress status and antioxidant content in the pig intestine. Our data revealed that a low-fiber diet contributed to oxidative stress in the pig intestine (jejunum). Pigs fed a high-fiber diet had less intestinal oxidative stress and grew heavier. Pigs fed a low-fiber diet may produce more antioxidants to cope with the increased oxidative stress in the intestine.

Effects of dietary protein content and crystalline amino acid supplementation patterns on growth performance, intestinal histomorphology, and immune response in weaned pigs raised under different sanitary conditions.

The aim of this experiment was to investigate the effects of dietary crude protein (CP) contents and crystalline amino acids (CAA) supplementation patterns on growth performance, intestinal histomorphology, and immune response in weaned pigs under clean (CSC) or unclean sanitary conditions (USC). A total of 144 weaned pigs (6.35 ± 0.63 kg body weight) were assigned to 6 treatments in a 3 × 2 factorial arrangement based on CP content and sanitary conditions using a randomized complete block design, giving 8 replicates per treatment with 3 pigs per pen. Pigs were fed one of three diets for 21 d: one high CP (HCP; 22%) and two low CP (LCP; 19%) diets supplemented with 9 indispensable AA or only 6 AA (Lys, Met, Thr, Trp, Val, and Ile) as CAA. The CSC room was washed weekly, whereas the USC room had sow manure spread in the pens and was not washed throughout the experiment. Body weight and feed disappearance were recorded weekly. Blood was sampled from 1 pig per pen weekly, and the same pig was euthanized for jejunal tissues sampling on day 21. Pigs raised under USC had reduced (P < 0.05) average daily gain (ADG) and gain to feed ratio (G:F) in week 2, but contrary results that greater (P < 0.05) ADG and G:F were found in pigs under USC in week 3. Overall, there was an interaction where G:F did not differ between HCP and LCP under CSC, however, LCP decreased (P < 0.05) G:F compared to HCP under USC. Pigs fed the HCP diet had higher (P < 0.05) fecal scores than those fed the LCP diets throughout the experiment. Pigs fed the LCP had higher (P < 0.05) villus height to crypt depth ratio than those fed the HCP. An interaction was observed where goblet cell density in the jejunum was higher (P < 0.05) in pigs fed LCP than HCP under CSC, but no difference was found between HCP and LCP under USC. Different CAA supplementation patterns did not influence both growth performance and histomorphology. Pigs raised under USC had greater (P < 0.05) plasma interleukin (IL)-10 and IL-6 concentrations and reduced (P < 0.05) plasma tumor necrosis factor-alpha concentration. Also, the LCP diets resulted in a greater (P < 0.05) plasma IL-10 concentration. In conclusion, overall growth performance did not differ between HCP and LCP under CSC, but LCP diets reduced G:F under USC. Feeding LCP diets to weaned pigs improved gut morphology under USC and ameliorated systemic inflammation induced by USC, whereas CAA supplementation patterns did not affect growth performance and gut morphology.

Reducing dietary crude protein (CP) content reduces nitrogen excretion to the environment and undigested protein availability to enteric pathogens in the hind gut resulting in reduced postweaning diarrhea and improved gut health. To meet the amino acid requirements in low CP diets, supplementation of essential amino acids in nursery diets is necessary, and the availability of more feed-grade crystalline amino acids allows low CP diets to be practically formulated. The sanitation challenge model mimics commercial raising conditions and stimulates a low-grade inflammatory and immune response. Although low CP diets decreased the feed efficiency in pigs raised under unclean conditions in this study, improved gut histomorphology and ameliorated inflammatory response were obtained in pigs fed low CP diets. However, no effect was found in crystalline amino acids supplementation patterns. The outcomes of this study confirmed that low CP diets could be used to improve gut health and ameliorate immune response in weaned pigs.

Effects of l-Tryptophan and 1,25-Dihydroxycholecalciferol on Proliferation and Osteogenic Differentiation of Mesenchymal Stem Cells Isolated from the Compact Bones of Broilers and Layers.

Poultry is vulnerable to bone problems throughout their lives or production period due to rapid growth in broilers and the active laying cycle in layers. The calcium-sensing receptor (CaSR) is important in calcium and bone metabolism. The objective of this study was to investigate the effect of the CaSR ligand (l-Trp) and 1,25-dihydroxycholecalciferol (1,25OHD3) on the regulation of proliferation and osteogenic differentiation of chicken mesenchymal stem cells (MSCs) isolated from the compact bones of 14-day-old Ross 308 chickens and Dekalb pullets, which can provide cell-based evidence for the prevention or alleviation of skeletal disorders in the poultry industry. First, the dose- (0, 0.5, 1, 2, 5, 10, and 15 mM) and time-effects (0, 7, and 14 days) of l-Trp on the proliferation and osteogenic differentiation in chicken MSCs were investigated. The 5 mM l-Trp had a balanced effect between proliferation and osteogenic differentiation in broiler and layer MSCs when differentiated for 7 days. The broiler and layer MSCs were then treated with (1) osteogenic medium, osteogenic medium supplemented with (2) 1 nM 1,25OHD3, (3) 2.5 mM Ca2+, (4) 2.5 mM Ca2+ + 5 mM l-Trp and (5) 2.5 mM Ca2+ + 5 mM l-Trp + 1 µM NPS-2143, separately for 7 days. Results showed that the 5 mM l-Trp significantly inhibited the proliferation of broiler and layer MSCs on day 7 (P < 0.05), but 1 nM 1,25OHD3 significantly promoted the proliferation of layer MSCs (P < 0.05). Only the 2.5 mM Ca2+ + 5 mM l-Trp group significantly increased the mineralization process during osteogenic differentiation (P < 0.05), and this treatment also significantly upregulated the mRNA expression of the vitamin D receptor (VDR), ß-catenin, and osteogenesis genes in broiler MSCs (P < 0.05). The osteogenic differentiation process in layer MSCs was faster than that in broiler MSCs. In layer MSCs, Ca2+ alone significantly facilitated mineralization and ALP activity after 7-day osteogenic differentiation (P < 0.05). However, the 5 mM l-Trp significantly inhibited the differentiation and mineralization process by downregulating the mRNA expression of CaSR, VDR, ß-catenin, and osteogenic genes (P < 0.05) in layer MSCs. Taken together, l-Trp and 1,25OHD3 can regulate proliferation and osteogenic differentiation in both broiler and layer MSCs depending on the dose, treatment time, and cell proliferation and differentiation stages.