Potential of blended organic acids to improve performance and health of broilers infected with necrotic enteritis

Organic acids (OA) and their blends have been shown to positively affect performance and health of broilers. However, the data in the literature are not consistent. This study examined the potential of blended short-chain fatty acids (SCFA) with medium-chain fatty acids (MCFA) as alternatives to antibiotic growth promoters (AGP) on performance, health and welfare of broilers infected with necrotic enteritis (NE). The additives used were: A) a blend of SCFA, MCFA, and a phenolic compound (SMP); B) a blend of free and buffered SCFA with MCFA (SMF); C) a blend of free and buffered SCFA with a high concentration of MCFA (SHM). A total of 1,404 Ross 308 one-day-old male parental chicks were randomly distributed into 78-floor pens with 13 replicates of 18 birds each. Six treatments were the following: T1, unchallenged control (UCC); T2, challenged control (CHC); T3, challenged group plus zinc bacitracin (BAC); T4, challenged group plus additive SMP; T5, challenged group plus additive SMF; T6, challenged group plus additive SHM. Challenged birds were gavaged with Eimeria spp. on d 9 and Clostridium perfringens EHE-NE18 on d 14. Post NE challenge and cumulatively, BWG, FCR, and nutrient digestibility of birds were compromised (P < 0.05) by NE challenge indicating a successful induction of sub-clinical NE. Additive SHM had higher BWG compared to CHC and BAC groups (P = 0.001; d 10 to 24) but not different from SMP and SMF groups (P > 0.05). All the 3 additive groups had lower FCR compared to CHC (P = 0.001; d 0 to 35), and exhibited similar jejunal lesions (d 16) compared to BAC and apparent ileal protein digestibility (d 21) compared to UCC and BAC groups (P > 0.05). Birds in additive SHM group had a higher concentration of serum IgA compared to all groups (P = 0.001) except additive SMF (P > 0.05; d 21). All the additive groups had lower footpad dermatitis and hock burns compared to CHC (P < 0.05). The findings suggest the potential of blended OA as alternatives to BAC to protect broilers from NE indicated by improved FCR, immunity, digestibility, and bird welfare.     

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

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

Over-processed meat and bone meal and phytase effects on broilers challenged with subclinical necrotic enteritis: Part 3. Bone mineralization and litter quality

This study was conducted to determine the effect of necrotic enteritis (NE), phytase level and meat and bone meal (MBM) processing on bone mineralization of broilers and litter quality. Ross 308 male broiler chicks (n = 768) were allotted to 48 pens with 16 birds each. There were 8 dietary treatments in a 2 × 2 × 2 factorial arrangement. Factors were NE challenge (no or yes), phytase level (500 or 5,000 FTU/kg), and MBM (as-received or over-processed). Half of the birds were challenged with field strains of Eimeria spp. at d 9 and 10⁸ CFU per mL of Clostridium perfringens strain EHE-NE18 on d 14 and 15. The middle toe, tibia and femur of 2 birds per pen were excised at d 16 and 29 for determination of ash, breaking strength (BS) and bone mineralization. At d 42, all were assessed for hock burns and litter was scored and assessed for dry matter (DM). At d 16, challenged birds had lower toe ash (P < 0.01), femur ash (P < 0.001), tibia ash (P < 0.001) and tibial BS (P < 0.001) than unchallenged birds. At d 16, challenged birds fed high phytase and over-processed MBM had higher toe Mn than those fed low phytase and as-received MBM. At d 29 unchallenged birds fed high phytase and as-received MBM had a higher toe Mn than those fed over-processed MBM. At d 16, a phytase × MBM interaction was detected for femur Zn concentration (P < 0.05), where a higher level of Zn was observed in the high phytase group fed over-processed MBM. At d 16, tibial Ca (P < 0.05) and P (P < 0.05) were lower in the challenged whereas the femur K (P < 0.001), Mn (P < 0.01) and Na (P < 0.001) were higher in the challenged at d 16. At d 42, challenged birds had higher litter DM (P = 0.058) and fewer hock burns than those unchallenged (P < 0.05). In conclusion, NE impaired bone traits but high phytase and over-processed MBM increased bone mineral contents. Cases of hock burns may be lower under NE incidences due to lower livability of birds reducing litter wetness.     

Net energy,energy utilization,and nitrogen and energy balance affected by dietary pea supplementation in broilers

Pea starch consists predominantly of C-type of amylopectin chain which is more resistant to digestive enzymes than A-type of starch thus slowly digested in poultry. It was hypothesized that the presence of slowly digested pea starch in broiler diets will increase net energy and the efficiency of energy utilization in broilers. Two experiments were performed to investigate starch digestibility of pea at different incubation times (in vitro study) and the effect of dietary pea on heat increment and net energy in broilers using an open-circuit respiratory calorimetry system (in vivo study). One-day-old Ross 308 male broilers were fed a common starter crumble from d 1 to 10 and standard grower diets thereafter. At d 21, birds were transferred to the chambers each housing 2 birds. Each treatment was replicated 6 times with 2 identical runs of 3 replicates per treatment. A wheat-soybean meal-based diet was used as a control and the treatment diet contained 500 g of pea/kg pea. In vitro study showed that pellet processing increased (P < 0.001) starch digestibility, particularly at shorter times for wheat and a much larger response for pea. Birds offered the pea-based diet had lower (P = 0.002) feed intake, lower (P = 0.020) body weight gain, but a similar (P > 0.05) FCR compared to those offered the wheat-based diet. Net energy (NE) and apparent metabolizable energy (AME) values were higher in the pea-based diet than in the wheat-based diet (P = 0.037 for NE and P = 0.018 for AME). Heat production, respiratory quotient, heat increment of feed, efficiency of utilization of gross energy for AME, and efficiency of utilization of AME for NE did not differ (P > 0.05) between the 2 treatments. There was no effect (P > 0.05) of pea on the total tract digestibilities of dry matter, crude protein and ash, but the total tract digestibility of starch was higher (P = 0.022) in the pea-based diet compared to the wheat-based diet. This study provides insight into the energy metabolism of broilers offered a pea-based diet and indicates that dietary pea supplementation increases dietary AME and NE but has no effect on heat increment of feed and the efficiency of energy utilization in broilers.     

Multi-carbohydrase enzymes improve feed energy in broiler diets containing standard or low crude protein

This study evaluated the effect of multi-carbohydrase (MC) on energy and nitrogen (N) balance and gene expression in broilers fed diets with different crude protein (CP) contents. The study employed a 2 × 2 factorial arrangement of treatments. The factors were presence or absence of MC, and standard (SCP) or low (LCP) dietary CP concentration. A 3-phase feeding program was used, including starter (0 to 7 d), grower (8 to 17 d) and finisher (18 to 28 d) phases. The study was undertaken in closed calorimetry chambers. Each of the 4 dietary treatments was replicated 8 times in total across 2 runs, with 2 birds per replicate (n = 64). Data for energy partitioning and N balance were collected from d 25 to 28. On d 28, birds were euthanized to collect muscle and intestinal tissue samples for gene expression. The results showed that the MC increased apparent metabolizable energy (AME, P < 0.01) and net energy (NE, P < 0.05), and reduced the feed conversion ratio (FCR, P < 0.01) in all diets. The proportion of energy retained as fat per total energy retention (REf/RE) was positively correlated with feed AME and NE (r = 0.541, P < 0.01 and r = 0.665, P < 0.001, respectively), suggesting that feed energy augmented with increased fat gain. Muscle ATP synthase subunit alpha (ATP5A1W) gene expression had a positive correlation with REf/RE and feed NE (r = 0.587, P < 0.001 and r = 0.430, P < 0.05, respectively). Similarly, muscle peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1A) expression was negatively correlated with weight gain and positively correlated with FCR (r = −0.451, P < 0.05 and r = 0.359, P < 0.05, respectively). These correlations show that over-expressions of muscle genes related to energy production reduce bird performance. This study demonstrated that MC increase dietary energy utilization, regardless of dietary CP concentration. However, the energy released by the enzymes increases feed energy-to-CP ratio, meaning there is excess energy that is then deposited as body fat. This suggests that supplemental MC in broiler feeds is beneficial if diets are formulated to contain marginal energy levels.     

Influence of barley inclusion method and protease supplementation on growth performance,nutrient utilisation,and gastrointestinal tract development in broiler starters

The influence of the method of barley inclusion(fine,coarse and whole barley)in a wheat-based diet and protease supplementation(0 and 0.20 g/kg)on growth performance,nutrient utilisation and gastrointestinal tract development of broilers(d 1 to 21)was evaluated in a 3
2 factorial arrangement.Whole barley(WB)grains were ground in a hammer mill to pass through the screen sizes of 2.5 and 8.0 mm to achieve fine(FB)and coarse(CB)barley particle sizes,respectively.A total of 288,one-day-old male broilers were allotted to 36 cages(6 cages/treatment;8 birds/cage).There was no significant(P>0.05)interaction between barley inclusion method and protease for any growth performance or nutrient utilisation parameters.Birds fed diets containing CB and WB showed higher(P<0.05)weight gain,and digestibility of dry matter,nitrogen,calcium,gross energy,and ileal digestible energy compared to those fed FB diets.Compared to the birds fed FB diets,feed per gain was lower(P<0.05)in birds fed diets made of WB.Fat digestibility of the birds fed CB was higher(P<0.05)than those fed FB and WB birds.Compared to FB and CB diets,inclusion of WB resulted in heavier(P<0.05)gizzards but reduced(P<0.05)gizzard pH.Supplemental protease,however,had no effects(P>0.05)on growth performance and nutrient utilisation,most likely due to the well balanced digestible amino acids and high inherent digestibility of protein in the basal diet,and/or the presence of exogenous carbohydrase and phytase.In conclusion,the present results showed that the inclusion of coarsely ground and whole barley in a wheat-based diet can enhance nutrient and energy utilisation and is beneficial to the growth performance of young broilers.     

Interaction between xylanase and a proton pump inhibitor on broiler chicken performance and gut function

Three hundred thirty-six Ross 308 male broiler chicks were used in a 21-d study to explore performance and gut function when treated with a proton pump inhibitor(PPI;0 or 89 mg/kg)in a 2×2 factorial arrangement with a xylanase(Xyl;0 or 0.1 g/kg)to determine if the beneficial activity of arabinoxylan(AX)depolymerisation,through arabinoxylo-oligosaccharides(AXOS)production,starts in the upper gastrointestinal tract.Treatment with the PPI started from d 14,and by d 21 animal performance had deteriorated(P<0.001).An interaction was observed between PPI and Xyl for feed conversion ratio(FCR)(P<0.05),whereby the combination reduced the negative effect of PPI on FCR.Application of PPI raised digesta pH in the gizzard and caecum(P<0.05),increased protein concentrations in the lower gut(P<0.05)and reduced intake of digestible nutrients(P<0.05).Caecal concentrations of indole,p-cresol,ammonia and the ratio of total volatile fatty acid(VFA)to butyric acid were increased with PPI(P<0.05),indicating enhanced protein fermentation.Xylanase activity in the digesta were greatest in the caeca,especially when Xyl was supplemented(P<0.001).The concentration of total soluble AX was greater in the gizzard and ileal digesta with Xyl supplementation(P<0.05),supporting the depolymerisation action of xylanase even under acidic conditions.These data suggest xylanase may function in the gizzard even though pH is not optimal for activity and emphasises the importance of chlorohydric acid secretions in ensuring overall optimum gut function.AX depolymerisation benefits animal performance although it is still unknown how the AXOS produced with xylanase supplementation in the upper gastrointestinal tract influence the microbial populations and overall gut functionality.     

Characterisation of undigested components throughout the gastrointestinal tract of broiler chickens fed either a wheat-or maizebased diet

This study was to characterise the undigested nutrients present along the gastrointestinal tract of birds offered common wheat-or maize-based diets, with the goal of optimising utilisation of enzymes to enhance digestive efficiency. Wheat-and maize-based diets were offered to 240 mixed-sex broilers(10birds/pen; n = 12) from 1 to 35 d post-hatch. Digestibility of dry matter, starch, crude protein and nonstarch polysaccharides(NSP) were measured in the crop, gizzard, duodenum, jejunum, ileum, caec...     

Evaluation of xylanase and a fermentable xylo-oligosaccharide on performance and ileal digestibility of broiler chickens fed energy and amino acid deficient diets

The objective of this study was to evaluate the effect of a product consisting of a combination of xylanase and xylo-oligosaccharide (STBIO) on performance and ileal digestibility of broiler chickens fed energy and amino acid (AA) deficient diets. Day-old male Ross 308 broiler chicks were randomly allocated to 8 pens per treatment, with 25 chicks per pen. Treatments based on wheat-corn-soybean meal diets were arranged in a 3 × 2 factorial design: a positive control that met or exceeded nutrient recommendations (PC), a negative control diet with a 50 kcal/kg apparent metabolizable energy (AME) reduction (NC1) and NC1 with a 3% reduction in AA content (NC2), each with or without supplementation of 100 g/t of the STBIO. Body weight gain (BWG), feed intake, feed conversion ratio corrected for mortality (FCR) and the European production efficiency factor (EPEF) were recorded from 0 to 42 d. On d 42, ileal samples were collected to determine dry matter (DM), organic matter (OM), ash, protein and energy digestibility. A significant interaction was observed for BWG and feed intake (P < 0.001). The energy and AA reduction reduced (P < 0.05) BWG when compared to the PC. The effect of STBIO on BWG was greater in NC1 (+451 g/bird) than in NC2 (+314 g/bird) or PC (+176 g/bird) diets (P < 0.05), and that in NC2 with STBIO was equal to that in PC without STBIO, and that in NC1 with STBIO was equal to that in PC with STBIO. No interactions were observed on the EPEF or FCR; however, STBIO improved EPEF (P < 0.001) and FCR (P < 0.001) irrespective of the energy reduction or AA density. The intake of digestible DM, OM, ash and energy for the finisher period was increased with STBIO supplementation (P < 0.01). A significant interaction was observed for the intake of digestible protein. NC1 and NC2 reduced the intake of digestible protein; however, when STBIO was supplemented, it was improved in both diets to similar levels to the PC. The stimbiotic supplementation improved performance of broiler chickens fed all diets, particularly those deficient in AME and AA.     

Changes in progenitors and differentiated epithelial cells of neonatal piglets

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

Balanced nutrient density for broiler chickens using a range of digestible lysine-to-metabolizable energy ratios and nutrient density:Growth performance,nutrient utilisation and apparent metabolizable energy

Currently, specific nutrient concentration, metabolizable energy (ME) and digestible amino acids are used as feed formulation criteria. A balanced nutrient density (BND) concept based on 2 criteria of nutrient density and balanced amino acids-to-ME ratio may offer more flexibility in optimisation of profit in formulation of diets compared with current formulation based on set values per unit of feed mass. A total of 672 one-d-old off-sex male Ross 308 broiler chickens were used across two 42-d performance trials in a 3 × 2 factorial arrangement of treatments with each diet replicated 8 times (14 birds per replicate). The experimental factors were 2 nutrient density levels (low [LD] and high [HD]) and 3 digestible lysine-to-ME ratios (DLYS:ME; low, medium, and high). Low density diets had ME of 2,876 and 3,023 kcal/kg for starter and finisher, respectively, while values for HD diets were 3,169 and 3,315 kcal/kg with proportionally higher non-nitrogenated nutrients. Separate digestibility and apparent metabolizable energy (AME) assays were conducted at d 21 and 42. Digestibility assays at d 7 were conducted on birds used for performance trials. Regardless of the diet density, birds fed low DLYS:ME had a lower (P < 0.01) feed intake (d 0 to 42) than medium and high DLYS:ME. Without interaction, birds fed low and medium DLYS:ME had a similar body weight gain being the heaviest while birds low DLYS:ME were the lightest. By an interaction (P < 0.05), the highest overall FCR value was observed for birds fed LD × low DLYS:ME and improved linearly when DLYS:ME increased to the highest level reaching a limit for birds fed HD × medium DLYS:ME. Calorie conversion linearly decreased (P < 0.001) with increments in DLYS:ME. Jejunal and ileal starch and protein digestibility were affected on d 21 and 42 but not on d 7 of age. Given the independence of response on BW and feed consumption, the use of BND as a flexible system in diet formulations has the potential to enable more accurate formulation for optimisation of growth performance of broiler chickens.     

Bacillus amyloliquefaciens CECT 5940 improves performance and gut function in broilers fed different levels of protein and/or under necrotic enteritis challenge

Two studies were conducted to investigate the effect of Bacillus amyloliquefaciens CECT 5940 (BA) as a probiotic on growth performance, amino acid digestibility and bacteria population in broiler chickens under a subclinical necrotic enteritis (NE) challenge and/or fed diets with different levels of crude protein (CP). Both studies consisted of a 2 × 2 factorial arrangement of treatments with 480 Ross 308 mix-sexed broiler chickens. In study 1, treatments included 1) NE challenge (+/−), and 2) BA (1.0 × 10⁶ CFU/g of feed) supplementation (+/−). In study 2, all birds were under NE challenge, and treatments were 1) CP level (Standard/Reduced [2% less than standard]) and 2) BA (1.0 × 10⁶ CFU/g of feed) supplementation (+/−). After inducing NE infection, blood samples were taken on d 16 for uric acid evaluation, and cecal samples were collected for bacterial enumeration. In both studies, ileal digesta was collected on d 35 for nutrient digestibility evaluation. In study 1, the NE challenge reduced body weight gain (BWG), supressed feed conversion ratio (FCR) and serum uric acid levels (P < 0.001). Supplementation of BA increased BWG (P < 0.001) and reduced FCR (P = 0.043) across dietary treatments, regardless of challenge. Bacillus (P = 0.030) and Ruminococcus (P = 0.029) genomic DNA copy numbers and concentration of butyrate (P = 0.017) were higher in birds fed the diets supplemented with BA. In study 2, reduced protein (RCP) diets decreased BWG (P = 0.010) and uric acid levels in serum (P < 0.001). Supplementation of BA improved BWG (P = 0.001) and FCR (P = 0.005) and increased Ruminococcus numbers (P = 0.018) and butyrate concentration (P = 0.033) in the ceca, regardless of dietary CP level. Further, addition of BA reduced Clostridium perfringens numbers only in birds fed with RCP diets (P = 0.039). At d 35, BA supplemented diets showed higher apparent ileal digestibility of cystine (P = 0.013), valine (P = 0.020), and lysine (P = 0.014). In conclusion, this study suggests positive effects of BA supplementation in broiler diets via modulating gut microflora and improving nutrient uptake.     

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

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

Production performance and plasma metabolite concentrations of broiler chickens fed low crude protein diets differing in Thr and Gly

The aim of the study was to test the interaction between Thr and Gly in low crude protein (CP) diets in 7 to 28 d broilers on production performance and plasma metabolites. A total of 2,040 broilers were allocated to 17 treatments. A positive control (PC) diet (20.5% CP) was formulated to be adequate in dietary Thr and Gly. A negative control (NC) diet (18.5% CP, deficient in Thr and Gly) was supplemented with crystalline l-Thr and Gly to obtain a 4 Thr × 4 Gly design. Dietary Thr was tested at an apparent faecal digestibility (AFD) Thr-to-Lys ratio, which was 55%, 58%, 61% or 64%, and dietary Gly was tested at an AFD (Gly + Ser)-to-Lys ratio, which was 135%, 142%, 149% or 156%. Plasma samples were collected at 28 d. The low CP diet, formulated at 64% Thr and 156% Gly, resulted in a higher body weight gain (BWG) (P < 0.01) and similar feed conversion ratio (FCR) as the high CP treatment (PC). FCR was improved (P < 0.001) by l-Thr supplementation. Quadratic response to dietary Thr was significant for feed intake (FI), BWG and FCR (P < 0.01). A near-significant interaction for Thr × Gly was observed for FI and BWG (P_linear = 0.091 and P = 0.074, respectively). Gly did not affect production performance. An interaction between Thr × Gly on plasma free AA level was observed (P < 0.05). Free AA concentration in plasma linearly decreased with increase in AFD Thr-to-Lys ratio, and increased with increase in AFD (Gly + Ser)-to-Lys ratio. Plasma uric acid concentration was higher in PC than in all of the other diets, and plasma triglyceride concentration was decreased by l-Thr supplementation, but not by Gly. In conclusion, Gly was not limiting for growth at low dietary CP level unless Thr was deficient, showing that adequate amounts of Thr in broiler diets can overcome marginal supply of Gly and Ser and allow reduction of dietary CP from 20.5% to 18.5% for broilers from 7 to 28 d of age.     

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

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

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

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

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

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

Dietary 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.     

Necrotic enteritis challenge regulates peroxisome proliferator-1 activated receptors signaling and β-oxidation pathways in broiler chickens

Necrotic enteritis (NE) is an important enteric disease in poultry and has become a major concern in poultry production in the post-antibiotic era. The infection with NE can damage the intestinal mucosa of the birds leading to impaired health and, thus, productivity. To gain a better understanding of how NE impacts the gut function of infected broilers, global mRNA sequencing (RNA-seq) was performed in the jejunum tissue of NE challenged and non-challenged broilers to identify the pathways and genes affected by this disease. Briefly, to induce NE, birds in the challenge group were inoculated with 1 mL of Eimeria species on day 9 followed by 1 mL of approximately 10⁸ CFU/mL of a NetB producing Clostridium perfringens on days 14 and 15. On day 16, 2 birds in each treatment were randomly selected and euthanized and the whole intestinal tract was evaluated for lesion scores. Duodenum tissue samples from one of the euthanized birds of each replicate (n = 4) was used for histology, and the jejunum tissue for RNA extraction. RNA-seq analysis was performed with an Illumina RNA HiSeq 2000 sequencer. The differentially expressed genes (DEG) were identified and functional analysis was performed in DAVID to find protein–protein interactions (PPI). At a false discovery rate threshold <0.05, a total of 377 DEG (207 upregulated and 170 downregulated) DEG were identified. Pathway enrichment analysis revealed that DEG were considerably enriched in peroxisome proliferator-activated receptors (PPAR) signaling (P < 0.01) and β-oxidation pathways (P < 0.05). The DEG were mostly related to fatty acid metabolism and degradation (cluster of differentiation 36 [CD36], acyl-CoA synthetase bubblegum family member-1 [ACSBG1], fatty acid-binding protein-1 and -2 [FABP1] and [FABP2]; and acyl-coenzyme A synthetase-1 [ACSL1]), bile acid production and transportation (acyl-CoA oxidase-2 [ACOX2], apical sodium–bile acid transporter [ASBT]) and essential genes in the immune system (interferon-, [IFN-γ], LCK proto-oncogene, Src family tyrosine kinase [LCK], zeta chain of T cell receptor associated protein kinase 70 kDa [ZAP70], and aconitate decarboxylase 1 [ACOD1]). Our data revealed that pathways related to fatty acid digestion were significantly compromised which thereby could have affected metabolic and immune responses in NE infected birds.     

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

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