Background Necrotic enteritis(NE)in broiler chickens leads to significant economic losses in poultry production.This study examined the inhibitory effects of usnic acid and tannic acid on coccidia,sporozoite,and Clost...Background Necrotic enteritis(NE)in broiler chickens leads to significant economic losses in poultry production.This study examined the inhibitory effects of usnic acid and tannic acid on coccidia,sporozoite,and Clostridium perfringens and assessed their influence on growth performance and intestinal health in NE-challenged broilers through in vitro and in vivo experiments.Methods The in vitro experiment included 5 treatment groups:the negative control(NC),2μmol/L diclazuril(DZ),30μmol/L usnic acid(UA),90μmol/L tannic acid(TA),and 15μmol/L usnic acid^(+)45μmol/L tannic acid(UTA)groups.The in vivo experiment involved 320 broilers divided into four groups:PC(NE-challenged),SA(500 mg/kg salinomycin premix^(+)NE-challenged),UA(300 mg/kg usnic acid^(+)NE-challenged),and UTA(300 mg/kg usnic acid^(+)500 mg/kg tannic acid^(+)NE-challenged)groups.Results In the in vitro study,the UA,TA,and UTA treatments significantly increased apoptosis in coccidian oocysts and sporozoites,lowered the mitochondrial membrane potential(P<0.05),and disrupted the oocyst structure compared with those in the NC group.UA and TA had inhibitory effects on C.perfringens,with the strongest inhibition observed in the UTA group.The in vivo results demonstrated that the SA group presented significantly improved growth performance on d 13,21,and 28(P<0.05),whereas the UA and UTA groups presented improvements on d 13 and 21(P<0.05).The SA,UA,and UTA treatments reduced the intestinal lesion scores by d 28 and the fecal coccidian oocyst counts from d 19 to 21(P<0.05).Compared with the PC group,the UA and UTA groups presented lower intestinal sIgA levels and CD8^(+)cell percentages(P<0.05),with a trend toward a reduced CD3^(+)cell percentage(P=0.069).The SA,UA,and UTA treatments significantly reduced the serum diamine oxidase activity,crypt depth,and plateletderived growth factor levels in the intestinal mucosa while increasing the villus height to crypt depth ratio and number of goblet cells(P<0.05).The UTA treatment also significantly increased the acetate and butyrate concentrations in the cecum(P<0.05).With respect to the gut microbiota,significant changes inβdiversity in the ileum and cecum were observed in the SA,UA,and UTA groups,indicating that the microbial community compositions differed among the groups.Romboutsia dominated the SA group,Bacillales dominated the UA group,and Lactobacillales and Lachnospirales dominated the UTA group in the ileal microbiota.In the cecal microbiota,Lactobacillus,Butyricicoccus,and Blautia abundances were significantly elevated in the UTA group(P<0.05).Conclusion Usnic acid and tannic acid induce apoptosis in coccidia and sporozoites by lowering the mitochondrial membrane potential.Both usnic acid alone and in combination with tannic acid alleviate NE-induced adverse effects in broilers by modulating intestinal immunity,altering the microbial composition,and improving intestinal barrier function.Compared with usnic acid alone,the combination of usnic acid and tannic acid had superior effects,providing a promising basis for the development of effective feed additive combinations.展开更多
Background Wheat and,to a lesser extent,sorghum are the dominant feed grains in Australian chicken-meat production.There is considerable local interest in the development of reduced-crude protein(CP)broiler diets in p...Background Wheat and,to a lesser extent,sorghum are the dominant feed grains in Australian chicken-meat production.There is considerable local interest in the development of reduced-crude protein(CP)broiler diets in part because this would decrease the need to import soybean meal into the country.Maize is rarely included in Australian broiler diets,but birds appear better able to accommodate dietary CP reductions with maize than with wheat-based diets.Sorghum is more similar to maize than wheat and for this reason wheat-and sorghum-based diets,with standard and reduced-CP concentrations,were evaluated in broiler chickens in a direct comparison.Results Reducing dietary CP from 205 to 175 g/kg CP did not statistically influence weight gain and FCR in broilers offered sorghum-based diets from 14 to 35 d post-hatch.In contrast,the 30 g/kg CP reduction compromised weight gain by 10.1%(1,964 versus 2,187 g/bird)and FCR by 9.68%(1.575 versus 1.436),in broilers offered wheat-based diets.Consequently,treatment interactions(P<0.001)were observed for dietary CP levels grain type for both weight gain and FCR.Another treatment interaction(P<0.001)was observed for starch digestibility coefficients in the distal jejunum.Birds offered 205 g/kg CP,wheat-based diets had superior starch digestibility by 11.6%(0.914 versus 0.819),but sorghum supported superior starch digestibility by 9.70%(0.837 versus 0.763)in the context of 175 g/kg CP diets.Conclusions Under the condition of thid study,broiler chickens offered sorghum-based diets had a greater capacity to accommodate dietary CP reductions than their counterparts offered wheat-based diets.This study confirmed that wheat-based diets are not conducive to CP reductions,but the causal factors have yet to be identified precisely.展开更多
Background Necrotic enteritis(NE)is an economically important disease of broiler chickens caused by Clostridium perfringens(CP).The pathogenesis,or disease process,of NE is still not clear.This study aimed to identify...Background Necrotic enteritis(NE)is an economically important disease of broiler chickens caused by Clostridium perfringens(CP).The pathogenesis,or disease process,of NE is still not clear.This study aimed to identify the alterations of metabolites and metabolic pathways associated with subclinical or clinical NE in CP infected birds and to investi-gate the possible variations in the metabolic profile of birds infected with different isolates of CP.Methodology Using a well-established NE model,the protein content of feed was changed abruptly before expos-ing birds to CP isolates with different toxin genes combinations(cpa,cpb2,netB,tpeL;cpa,cpb2,netB;or cpa,cpb2).Metabolomics analysis of jejunal contents was performed by a targeted,fully quantitative LC-MS/MS based assay.Results This study detected statistically significant differential expression of 34 metabolites including organic acids,amino acids,fatty acids,and biogenic amines,including elevation of butyric acid at onset of NE in broiler chickens.Subsequent analysis of broilers infected with CP isolates with different toxin gene combinations confirmed an eleva-tion of butyric acid consistently among 21 differentially expressed metabolites including organic acids,amino acids,and biogenic amines,underscoring its potential role during the development of NE.Furthermore,protein-metabolite network analysis revealed significant alterations in butyric acid and arginine-proline metabolisms.Conclusion This study indicates a significant metabolic difference between CP-infected and non-infected broiler chickens.Among all the metabolites,butyric acid increased significantly in CP-infected birds compared to non-infected healthy broilers.Logistic regression analysis revealed a positive association between butyric acid(coefficient:1.23,P<0.01)and CP infection,while showing a negative association with amino acid metabolism.These findings suggest that butyric acid could be a crucial metabolite linked to the occurrence of NE in broiler chickens and may serve as an early indicator of the disease at the farm level.Further metabolomic experiments using different NE animal models and field studies are needed to determine the specificity and to validate metabolites associated with NE,regardless of predisposing factors.展开更多
Background It is important to promote intestinal development and maturation of chicks for feed digestion and utilization,intestinal health,and disease resistance.This study aimed to investigate the effects of dietary ...Background It is important to promote intestinal development and maturation of chicks for feed digestion and utilization,intestinal health,and disease resistance.This study aimed to investigate the effects of dietary yeast cell wall polysaccharides(YCWP)addition on intestinal development and maturation of chickens and its potential action mechanism.Methods 180 one-day-old male Arbor Acres broilers were randomly assigned to three groups containing control(basal diets without any antibiotics or anticoccidial drug),bacitracin methylene disalicylate(BMD)-treated group(50 mg/kg)and YCWP-supplemented group(100 mg/kg).Results Compared with control group,in-feed antibiotic BMD continuous administration significantly decreased crypt depth(d 21)and villus height(d 42)along with mucosal maltase activity(d 42)in the ileum(P<0.05).Also,BMD markedly downregulated gene expression levels ofβ-catenin,lysozyme,occludin and FABP-2(d 21)and innate immune related genes CD83 and MHC-I mRNA levels(d 42,P<0.05),and decreased goblet cell counts in the ileum of chickens(d 21 and d 42,P<0.05).While,TLR-2,TLR-6 and iNOS mRNA abundances were notably upregulated by BMD treatment(d 42,P<0.05).Nevertheless,dietary YCWP addition significantly increased the ratio of villus height to crypt depth(d 21),villus surface area(d 21 and d 42),ileal alkaline phosphatase and maltase activities as well as goblet cell(d 21 and d 42)and IgA-producing plasma cell numbers as compared to BMD treatment(d 21,P<0.05).YCWP addition also upregulated gene expression levels of Lgr5,Wnt/β-catenin signaling pathway related gene(Wnt3,β-catenin,d 21;β-catenin,d 42),intestinal cells proliferation marker Ki-67 and barrier function related genes(occludin,d 21 and d 42,P<0.05).Moreover,YCWP significantly increased antigen presenting cell marker related genes(MHC-II,d 21;CD83 and MHC-I,d 42),TLR-1,TLR-2 and TLR-6 mRNA levels(d 21,P<0.05).Cecal microbiome analysis showed that YCWP addition obviously improved cecal microbial composition,as indicated by increasing relative abundance of Fournierella,Psychrobacter and Ruminiclostridium on d 21,and Alistipes and Lactobacillus on d 42,which were positively related with gut development and maturation related indexes(P<0.05).Conclusion Collectively, YCWP promoted yet antibiotic BMD delayed intestinal morphological and immunologicaldevelopment linked with modulating gut microbiome in chickens.展开更多
The development of alternative therapies to treat chicken coccidiosis has become a hot topic because of the widespread use of conventional medicines.This study aimed to investigate the effectiveness of eugenol in trea...The development of alternative therapies to treat chicken coccidiosis has become a hot topic because of the widespread use of conventional medicines.This study aimed to investigate the effectiveness of eugenol in treating Eimeria tenella infection in broilers.Broiers,at the age of 14 d,were orally infected with sporulated Eimeria tenella oocysts,and then,eugenol essential oil was added to chicken feed at three different dosages(0.1,0.2 or 0.4 g/kg).The anticoccidial effects of eugenol essential oil were assessed using the anticoccidial index(ACI).As a result,eugenol exhibited a moderate anticoccidial effect,with an ACI of 167.37 at 0.2 g/kg.After eugenol treatment,the expression of occludin in the epithelial cells of the chicken cecum was significantly greater(P<0.05)than that in the epithelial cells of the nontreated control(IC)group.The proportion of intestinal Lactobacillus_agilli increased.Eugenol therapy dramatically increased the activity of superoxide dismutase.After high-dose treatment,the expression of the proinflammatory factors IL-1βand IL-6 significantly decreased,while the expression of the cytokines IL-4 and IFN-γsignificantly increased.The safety of eugenol essential oil was evaluated at the 1,3 or 6 recommended doses.Overall,no significant differences were detected in the blood tests or serum biochemistry of the chickens between the treatment groups and the control group.As a result,eugenol essential oil can cure chicken coccidiosis by improving the intestinal microbial structure in the chicken cecum and decreasing the cecum's inflammatory reactions,thus strengthening immune function and eventually demonstrating anticoccidial properties.展开更多
Background Salmonella enterica serovar Enteritidis(S.Enteritidis)is a global foodborne pathogen that poses a significant threat to human health,with poultry being the primary reservoir host.Therefore,addressing S.Ente...Background Salmonella enterica serovar Enteritidis(S.Enteritidis)is a global foodborne pathogen that poses a significant threat to human health,with poultry being the primary reservoir host.Therefore,addressing S.Enteritidis infections in poultry is crucial to protect human health and the poultry industry.In this study,we investigated the effect of co-housing Arbor Acres(AA)chickens,a commercial breed susceptible to S.Enteritidis,with Tibetan chickens,a local breed resistant to S.Enteritidis infection,on the resistance of the latter to the pathogen.Results Ninety-six 1-day-old Tibetan chickens and 961-day-old AA chickens were divided into a Tibetan chicken housed alone group(n=48),an AA chicken housed alone group(n=48),and a co-housed group(48 birds from each breed for 2 cages).All birds were provided the same diet,and the experimental period lasted 14 d.At d 7,all chickens were infected with S.Enteritidis,and samples were collected at 1-,3-,and 7-day-post-infection.We found that the body weight of AA chickens significantly increased when co-housed with Tibetan chickens at 1-and 3-day-post-infection(P<0.05).In addition,the cecal S.Enteritidis load in AA chickens was significantly reduced at 1-,3-,and 7-day-post-infection(P<0.05).Furthermore,the inflammatory response in AA chickens decreased,as evidenced by the decreased expression of proinflammatory cytokines NOS2,TNF-α,IL-8,IL-1β,and IFN-γin their cecal tonsils(P<0.05).Co-housing with Tibetan chickens significantly increased the height of villi and number of goblet cells(P<0.05),as well as the expression of claudin-1(P<0.05),a tight junction protein,in the jejunum of AA chickens.Further analysis revealed that co-housing altered the gut microbiota composition in AA chickens;specifically,the relative abundances of harmful microbes,such as Intestinimonas,Oscillibacter,Tuzzerella,Anaerotruncus,Paludicola,and Anaerofilum were reduced(P<0.05).Conclusions Our findings indicate that co-housing with Tibetan chickens enhanced the resistance of AA chickens to S.Enteritidis infection without compromising the resistance of Tibetan chickens.This study provides a novel approach for Salmonella control in practical poultry production.展开更多
Previous studies have shown that VGLL2,a member of the mammalian Vestigial-like(VGLL)family,plays important roles in the growth and development of animal skeletal muscle,but its specific role in the development of chi...Previous studies have shown that VGLL2,a member of the mammalian Vestigial-like(VGLL)family,plays important roles in the growth and development of animal skeletal muscle,but its specific role in the development of chicken skeletal muscle is unclear.The main goal of this study was to explore the biological functions of VGLL2 in the development of chicken skeletal muscle and the proliferation and differentiation of skeletal muscle cells in vitro.In this study,we detected the effect of VGLL2 on the proliferation of myoblasts by CCK8,EdU and flow cytometry analyses after overexpressing and interfering with VGLL2.Indirect immunofluorescence was used to detect the effect of VGLL2 on the differentiation of myoblasts.qRT-PCR and hematoxylin and eosin(H&E)staining were used to evaluate the effects of VGLL2 overexpression on the growth rate and muscle fiber structure of chicken skeletal muscle.The results showed that VGLL2 inhibited the proliferation of primary cultured chicken myoblasts and promoted the differentiation of these cells.Interestingly,food intake and muscle fiber development were significantly enhanced by the overexpression of VGLL2 in chickens.Taken together,these data demonstrate that the VGLL2 gene may be a useful marker for improving muscle mass in poultry.展开更多
Background Black soldier fly larvae meal(BSFLM)stands out as a promising nutritional resource due to its rich bioactive substances and favorable protein profile.Nonetheless,its potential to mitigate coccidia infection...Background Black soldier fly larvae meal(BSFLM)stands out as a promising nutritional resource due to its rich bioactive substances and favorable protein profile.Nonetheless,its potential to mitigate coccidia infection in broilers remains uncertain.This study aimed to evaluate the impact of partially defatted BSFLM(pBSFLM)on growth performance,nutrient utilization,and intestinal health,focusing on morphology,immunology,and cecal fermentation in coccidia-infected broilers.Methods Over the initial 13 d,480 newly-hatched Cobb 500 male birds were allocated to three diets with increasing pBSFLM concentrations(0,60,or 120 g/kg).At d 13 post hatching,chicks within each dietary group were further allotted to non-challenge or challenge subsets,generating six treatments in a 3×2 factorial arrangement.Challenged birds were orally administered oocysts of E.maxima,E.acervulina,and E.tenella(25,000:125,000:25,000).Results During the infection phase(d 13 to 19),linear interactions between Eimeria and pBSFLM were observed in gain to feed ratio(G:F)(P<0.05)and cecal interferon-γ(IFN-γ,P<0.05),with a tendency in cecal acetate concentration(P=0.06).A quadratic interaction was observed in crypt depth(CD,P<0.05).Incremental pBSFLM inclusion negatively affected G:F,CD,IFN-γ,and acetate productions in the ceca under coccidia challenge.Conversely in nonchallenged birds,the impact of pBSFLM varied from neutral(e.g.G:F)to potentially advantageous(e.g.acetate).Challenged birds exhibited decreased(P<0.01)BW,BW gain,feed intake(FI),and the apparent ileal digestibility and total tract nutrient utilization of DM,gross energy,and nitrogen(N).Eimeria challenge reduced(P<0.01)serum carotenoid concentrations,decreased the villus height to crypt depth ratio(VH:CD,P<0.01),and increased concentrations of branched-chain fatty acids,specifically isobutyrate(P=0.059)and isovalerate(P<0.05)in the cecum.Dietary pBSFLM addition linearly reduced(P<0.05)BW,FI,and N utilization.Tendencies(P<0.06)were observed where pBSFLM linearly decreased VH:CD and reduced goblet cell density.Conclusions Increasing pBSFLM supplementation,particularly at 12%,adversely affected growth,ileal morphology,cecal acetate production,and downregulated key cytokine expression in response to coccidia infection.展开更多
Mycoplasma gallisepticum(MG) is a common avian pathogen that mainly infects poultry, causingsignificant reductions in body weight gain and egg production, along with damage to immune organs andimmunosuppression. MG is...Mycoplasma gallisepticum(MG) is a common avian pathogen that mainly infects poultry, causingsignificant reductions in body weight gain and egg production, along with damage to immune organs andimmunosuppression. MG is susceptible to co-infections with other pathogens, leading to increased mortalityrates and significant economic losses in the global poultry industry. While antibiotics have been extensivelyapplied worldwide to treat MG infections in poultry production, concerns regarding antibiotic resistanceand residue remain prevalent. Traditional Chinese medicine(TCM), renowned for its natural, safe, andnon-toxic properties, has shown significant anti-inflammatory and immune-enhancing effects. This studyaimed to investigate the protective effect of TCM on production performance and its impact on MG-inducedimmunosuppression through the MAPK/ERK/JNK signaling pathway in chickens. Our results showed that TCMalleviated the negative effects of MG infection on production performance, as evidenced by improvements inbody weight gain, feed conversion rate, survival rate, and immune organ index. TCM exhibited direct inhibitionof the MG proliferation in vitro and in vivo. Furthermore, TCM treatment promoted the normalization of tracheaand lung tissue structure in MG-infected chickens, leading to a significant reduction in inflammatory damage.Moreover, following the treatment with the TCM, the production of pro-inflammatory cytokines interleukin-1β(IL-1β) and tumor necrosis factor-α(TNF-α) decreased significantly, accompanied by the downregulation of pro-apoptotic genes caspase3, caspase9, and BAX, both in vitro and in vivo. A mechanism-based study showed that in vitro and in vivo treatment with the TCM significantly reduced the expression of key proteins, including early growth response gene 1(EGR1), p-ERK, p-JNK, and p-JUN. Altogether, TCM improved body weight gain, inhibited pro-inflammation responses, and alleviated tissue damage by inhibiting the MAPK/ERK/JNK signaling pathway to protect the performance and immune system of MG-infected chickens.展开更多
[Objective] This study aimed to investigate the outer membrane protein （OMP） patterns of Escherichia coli 038, 053 and 075 isolates from chickens. [Method] Eight pathogenic E. coil isolates with various serotypes we...[Objective] This study aimed to investigate the outer membrane protein （OMP） patterns of Escherichia coli 038, 053 and 075 isolates from chickens. [Method] Eight pathogenic E. coil isolates with various serotypes were used as experimental materials to extract OMP by using supersonic schizolysis method and Sarcosyl. After SDS-PAGE electrophoresis, OMP patterns of the extracted products were determined based on the OMP model diagram. [Result] OMP of eight E. coil isolates with three serotypes were divided into three patterns, to be specific, 2 075 isolates respectively belonged to OMP-I and OMP-II pattern, 1 053 isolate belonged to OMP-II pattern, and 5 038 isolates belonged to OMP-I and OMP-III pattern. [Conclusion] Experimental results showed that E. coli isolates with the same serotype may belong to completely different OMP patterns, while serologically unrelated isolates may belong to the same OMP pattern. OMP of E. coil isolates with the same serotype may generate genetic differentiation; in addition, OMP of E. coli isolates with different serotypes may have different genetic correlation.展开更多
Background: The poultry industry is in need of effective antibiotic alternatives to control outbreaks of necrotic enteritis(NE) due to Clostridium perfringens.Methods: This study was conducted to investigate the effec...Background: The poultry industry is in need of effective antibiotic alternatives to control outbreaks of necrotic enteritis(NE) due to Clostridium perfringens.Methods: This study was conducted to investigate the effects of feeding Bacil us coagulans on the growth performance and gut health of broiler chickens with C. perfringens-induced NE. Two hundred and forty 1-day-old broiler chicks were randomly assigned to a 2 × 2 factorial arrangement with two dietary B. coagulans levels(0 or 4 × 109 CFU/kg of diet) and two disease chal enge statuses(control or NE chal enged).Results: NE-induced reduction in body weight gain was relieved by the addition of B. coagulans into broiler diets compared with the NE-infected birds. NE infection damaged intestinal morphological structure, promoted intestinal C.perfringens growth and liver invasion, and enhanced anti-C. perfringens specific sI gA concentrations in the gut and specific IgG levels in serum compared with the uninfected birds. NE infection significantly(P < 0.05) decreased mucin-2(at 14 d post-infection(DPI), tol-like receptor 2(TLR2, at 7 and 14 DPI), TLR4(at 7 and 14 DPI), tumor necrosis factor super family15(TNFSF15, at 7 and 14 DPI), lysozyme(LYZ, at 14 DPI) and fowlicidin-2(at 7 and 14 DPI) mR NA levels, whereas it dramatical y(P = 0.001) increased IFN-γ mR NA levels at 7 DPI. However, chal enged birds fed diets supplemented with B.coagulans showed a significant(P < 0.01) decrease in gut lesion scores, decreased C. perfringens numbers in the cecum and liver, and an increase in fowlicidin-2 mR NA levels in compared with the uninfected birds. In addition, compared with the non-supplemented group, dietary inclusion of B. coagulans improved intestinal barrier structure, further increased specific sI gA levels and alkaline phosphatase(IAP) activity in the jejunum, enhanced the expression of jejunum lysozyme mR NA, and inhibited the growth, colonization, and invasion of C. perfringens; in contrast, it reduced serum-specific IgG concentrations and jejunum IFN-γ mR NA levels.Conclusion: These results indicated that dietary B. coagulans supplementation appeared to be effective in preventing the occurrence and reducing the severity of C. perfringens-induced NE in broiler chickens.展开更多
[Objective] This study aimed to investigate influencing factors and variation trends of muscle p H in chickens after slaughter. [Method] Beijing You chickens and Lohmann brown chickens were reared under the same condi...[Objective] This study aimed to investigate influencing factors and variation trends of muscle p H in chickens after slaughter. [Method] Beijing You chickens and Lohmann brown chickens were reared under the same conditions and slaughtered at the age of 8, 16 and 20 weeks, respectively. At different time（15 min, 1, 4, 8,12, 24 and 48 h） after slaughter, p H value of breast muscles and leg muscles was measured. [Result] The results showed that muscle position, post-slaughter time,gender and week age were important factors influencing p H value, but the breed had little effect. Within 1 h after slaughter, p H value of breast muscles and leg muscles declined rapidly, which reached the minimum level at 12 h after slaughter,and then increased slowly. In addition, p H value of leg muscles exhibited higher decline and increase rates than that of breast muscles to some extent. [Conclusion]This study provided basis for breeding of chickens with excellent meat quality.展开更多
Background: The present study has evaluated the effects of different inclusion levels of a partially defatted black soldier fly(Hermetia illucens L.; HI) larva meal on the growth performance, blood parameters and gut ...Background: The present study has evaluated the effects of different inclusion levels of a partially defatted black soldier fly(Hermetia illucens L.; HI) larva meal on the growth performance, blood parameters and gut morphology of broiler chickens. A total of 256 male broiler chickens(Ross 308) were reared from d 1 to d 35 and assigned to4 dietary treatments(8 replicates/treatment and 8 birds/replicate). HI larva meal was included at increasing levels(0, 5%, 10% and 15%; HI0, HI5, HI10 and HI15, respectively) in isonitrogenous and isoenergetic diets formulated for 3 feeding phases: starter(1–10 d), growing(10–24 d) and finisher(24–35 d). Two birds per pen were slaughtered at d 35 and morphometric investigations and histopathological alterations were performed.Results: The live weight(LW) showed linear and quadratic responses to increasing HI larva meal(maximum for HI10 group). Average daily gain(ADG) showed a linear and quadratic responses to HI meal(maximum for HI10 group) during starter and growing periods. A linear decrease was observed for ADG during the finisher period. The daily feed intake(DFI) showed a linear and quadratic effect during the starter period(maximum for HI10 group).Linear and quadratic responses were observed for the feed conversion ratio(FCR) in the growing period and for the whole period of the experiment. The FCR showed a linear response in the finisher period(maximum for HI15).No significant effects were observed for the blood and serum parameters, except for the phosphorus concentration,which showed linear and quadratic responses as well as glutathione peroxidase(GPx) activity, the latter of which showed a linear response. The HI15 birds showed a lower villus height, a higher crypt depth and a lower villus height-to-crypt depth ratio than the other groups.Conclusions: Increasing levels of dietary HI meal inclusion in male broiler chickens may improve the LW and DFI during the starter period, but may also negatively affect the FCR and gut morphology, thus suggesting that low levels may be more suitable. However, no significant effects on the haematochemical parameters or histological findings were observed in relation to HI meal utilization.展开更多
Genetic polymorphism of the major histocompatibility complex （MHC） B-LBⅡ gene was studied by amplification of exon 2 using PCR, followed by cloning and DNA sequencing in eight indigenous Chinese chicken populations...Genetic polymorphism of the major histocompatibility complex （MHC） B-LBⅡ gene was studied by amplification of exon 2 using PCR, followed by cloning and DNA sequencing in eight indigenous Chinese chicken populations. To reveal the genetic variation of the B-LB Ⅱ gene, 37 types of patterns detected by PCR-SSCP were investigated first, which would be used to screen novel B-LB Ⅱsequences within the breeds. The types of PCR-SSCP patterns and final sequencing allowed for the identification of 31 novel MHC B-LBⅡ alleles from 30 unrelated individuals of Chinese chickens that were sampled. These are the first designators for the alleles of chicken MHC B-LBⅡ gene based on the rule of assignment for novel mammalian alleles. Sequence alignment of the 31 B-LB Ⅱ alleles revealed a total of 68 variable sites in the fragment of exon 2, of which 51 parsimony informative and 17 singleton variable sites were observed. Among the polymorphic sites, the nucleotide substitutions in the first and second positions of the codons accounted for 36.76% and 35.29%, respectively. The sequence similarities between the alleles were estimated to be 90.6%-99.5%. The relative frequencies of synonymous and nonsynonymous nucleotide substitutions within the region were 2.92%±0.94% and 14.64%±2.67%, respectively. These results indicated that the genetic variation within exon 2 appeared to have largely arisen by gene recombination and balancing selection. Alignment of the deduced amino acid sequences of the β1 domain coded by exon 2 revealed 6 synonymous mutations and 27 nonsynonymous substitutions at the 33 disparate sites. In particular, the nonsynonymous substitutions at the putative peptide-binding sites are considered to be associated with immunological specificity of MHC B-LB Ⅱ molecule in Chinese native chickens. These results can provide a molecular biological basis for the study of disease resistance in chicken breeding.展开更多
Background： Colibacillosis caused by enterotoxigenic Escherichia coil （E. coil} results in economic losses in the poultry industry. Antibiotics are usually used to control colibacillosis, however, E. coli has varyin...Background： Colibacillosis caused by enterotoxigenic Escherichia coil （E. coil} results in economic losses in the poultry industry. Antibiotics are usually used to control colibacillosis, however, E. coli has varying degrees of resistance to different antibiotics. Therefore the use of probiotics is becoming accepted as an alternative to antibiotics. In this study, we evaluated the effects of Clostfidium butyricum （C. butyficum） on growth performance, immune response, intestinal barrier function, and digestive enzyme activity in broiler chickens challenged with Eschefichia coli （E. coil） K88. Methods： The chickens were randomly divided into four treatment groups for 28 days. Negative control treatment （NC） consisted of birds fed a basal diet without E. coil K88 challenge and positive control treatment （PC） consisted of birds fed a basal diet and challenged with E. coil K88. C. buO/ricum probiotic treatment （CB） consisted of birds fed a diet containing 2 x 107 cfu C. buO/ricum/kg of diet and challenged with E. coil K88. Colistin sulfate antibiotic treatment （CS） consisted of birds fed a diet containing 20 mg colistin sulfate/kg of diet and challenged with E. coil K88. Results： The body weight （BW） and average day gain （ADG） in the broilers of CB group were higher （P 〈 0.05） than the broilers in the PC group overall except the ADG in the 14-21 d post-challenge. The birds in CB treatment had higher （P 〈 0.05） concentration of tumor necrosis factor-a （TNF-a） at 3 and 7 d post-challenge, and higher （P 〈 0.05） concentration of interleukin-4 （IL-4） at 14 d post-challenge than those in the PC treatment group. The concentration of serum endotoxin in CB birds was lower （P 〈 0.05） at 21 d post-challenge, and the concentrations of serum diamine oxidase in CB birds were lower （P 〈 0.05） at 14 and 21 d post-challenge than in PC birds. Birds in CB treatment group had higher （P 〈 0.05） jejunum villi height than those in PC, NC, or CS treatment at 7, 14, and 21 d post-challenge. In comparison to PC birds, the CB birds had lower （P 〈 0.05） jejunum crypt depth during the whole experiment. The birds in CB or CS treatment group had higher （P 〈 0.05） activities of amylase and protease at 3, 7, and 14 d post-challenge, and higher （P 〈 0.05） activity of lipase at 3, 7 d post-challenge than PC birds.展开更多
Background: There is growing interest in carbohydrate and protein nutrition to enhance the efficiency of animal production.Reduced-crude protein diets depress environmental pollution and feeding cost,but the challenge...Background: There is growing interest in carbohydrate and protein nutrition to enhance the efficiency of animal production.Reduced-crude protein diets depress environmental pollution and feeding cost,but the challenge to their adoption is maintaining digestive function and growth performance of birds.The present study was conducted to evaluate the influence of different dietary starch sources and protein levels on intestinal functionality and mucosal amino acid catabolism.Methods: Six dietary treatments,based on maize and soybean meal,were offered to 360 AA+male chicks from 6 to 35 d post-hatch as a 3 × 2 factorial array.Either waxy rice or amylose was added to a conventional maize-soy diet to provide three sources of starch with different digestion rates and relatively high and low dietary protein levels.Growth performance,parameters of intestinal functionality and concentrations of free amino acid in the portal circulation were determined.Results: In the grower phase,starch source influenced(P < 0.02) weight gain as diets containing amylose supported significantly higher weight gains than waxy rice.Significant increase of ileal ATP concentrations and Na^+/K^+-ATPase activity were found in amylose treatment.Also,amylose decreased BrdU positive cell numbers and down-regulated m RNA expression for CASP-3.GOT activity in the ileum was higher(P < 0.01) in birds offered low protein diets and there was a trend(P = 0.057) for waxy rice as a starch source to increase ileal GOT activities.There was a significant influence on the concentration of seventeen amino acids in the portal circulation with tryptophan the one exception.Waxy rice as a starch source generated 13.6% and 22.4% numerically higher concentrations of non-essential amino acids than maize and amylose,respectively.Conclusions: Amino acid catabolism in the gut mucosa is subject to nutritional regulation.Given that amino acids can be spared from catabolism in the gut mucosa by supplementation of amylose,it follows their post-enteral availability would be improved and intestinal energy would be derived more efficiently from glucose.展开更多
Background： In the post-antibiotic era, essential oils （EO） are promising alternatives to growth-promoting antibiotics. The aim of the present study was to investigate the antibacterial activities of an EO product ...Background： In the post-antibiotic era, essential oils （EO） are promising alternatives to growth-promoting antibiotics. The aim of the present study was to investigate the antibacterial activities of an EO product and its components thymol and carvacrol in vitro, and the efficacy of EO to control Clostridium perffingens challenge in broiler chickens. Results： The in vitro minimum inhibitory concentration assay showed strong antibacterial activity of the EO product, thymol, and carvacrol against pathogenic Escherichia col~, C. perffingens, and Salmonella strains, and weak activity towards beneficial Lactobacillus strains. Besides, an additive effect was observed between thymol and carvacrol. The in vivo study was carried out with 448 male broiler chicks following a 4 x 2 factorial arrangement to test the effects of EO supplementation （0, 60, 120, or 240 mg/kg EO in wheat-based diet）, pathogen challenge （with or without oral gavage of C. perfr/ngens from day 14 to day 20） and their interactions. Each treatment consisted of eight replicate pens （seven birds/pen）. The challenge led to macroscopic gut lesions, and resulted in a significant increase in ileal populations of C. perffingens and Eschefichia subgroup （P ≤ 0.05） on day 21. Dietary EO supplementation did not influence C. perfringens numbers, but linearly alleviated intestinal lesions on day 21 and 28 （P= 0.010 and 0.036, respectively）, and decreased Eschefichia populations in ileum with increased EO dosages （P = 0.027 and 0.071 for day 21 and 28, respectively）. For caecum, EO quadratically influenced Lactobacillus populations on day 21 （P = 0.002）, and linearly decreased the numbers of total bacteria and Eschefichio on day 28 （P = 0.026 and 0.060, respectively）. Mean thymol and carvacrol concentrations in the small intestine were 0.21 and 0.20 μg/g in intestinal digesta （wet weight）, respectively, for birds fed 60 mg/kg EO, and 0.80 and 0.71 μg/g, respectively, for birds fed 240 mg/kg EO. Conclusions： These results indicated that dietary EO supplementation could affect intestinal microbiota and alleviate intestinal lesions in broilers, which may contribute in controlling C. perffingens infection in broiler chickens.展开更多
Some H5 viruses isolated in poultry or wild birds between 2020 and 2021 were found to be antigenically different from the vaccine strains(H5-Re11 and H5-Re12) used in China. In this study, we generated three new recom...Some H5 viruses isolated in poultry or wild birds between 2020 and 2021 were found to be antigenically different from the vaccine strains(H5-Re11 and H5-Re12) used in China. In this study, we generated three new recombinant vaccine seed viruses by using reverse genetics and used them for vaccine production. The vaccine strain H5-Re13 contains the hemagglutinin(HA) and neuraminidase(NA) genes of an H5 N6 virus that bears the clade 2.3.4.4 h HA gene, H5-Re14 contains the HA and NA genes of an H5 N8 virus that bears the clade 2.3.4.4 b HA gene, and H7-Re4 contains the HA and NA genes of H7 N9 virus detected in 2021. We evaluated the protective efficacy of the novel H5/H7 trivalent inactivated vaccine in chickens, ducks, and geese. The inactivated vaccine was immunogenic and induced substantial antibody responses in the birds tested. Three weeks after vaccination, chickens were challenged with five different viruses detected in 2020 and 2021: three viruses(an H5 N1 virus, an H5 N6 virus, and an H5 N8 virus) bearing the clade 2.3.4.4 b HA gene, an H5 N6 virus bearing the clade 2.3.4.4 h HA gene, and an H7 N9 virus. All of the control birds shed high titers of virus and died within 4 days post-challenge, whereas the vaccinated chickens were completely protected from these viruses. Similar protective efficacy against H5 viruses bearing the clade 2.3.4.4 h or 2.3.4.4 b HA gene was observed in ducks and geese. Our study indicates that the newly updated H5/H7 vaccine can provide solid protection against the H5 and H7 N9 viruses that are currently circulating in nature.展开更多
The prime purpose of this review is to explore the pathways whereby progress towards reduced-crude protein(CP)diets and sustainable chicken-meat production may be best achieved.Reduced-CP broiler diets have the potent...The prime purpose of this review is to explore the pathways whereby progress towards reduced-crude protein(CP)diets and sustainable chicken-meat production may be best achieved.Reduced-CP broiler diets have the potential to attenuate environmental pollution from nitrogen and ammonia emissions;moreover,they have the capacity to diminish the global chicken-meat industry’s dependence on soybean meal to tangible extents.The variable impacts of reduced-CP broiler diets on apparent amino acid digestibility coefficients are addressed.The more accurate identification of amino acid requirements for broiler chickens offered reduced-CP diets is essential as this would diminish amino acid imbalances and the deamination of surplus amino acids.Deamination of amino acids increases the synthesis and excretion of uric acid for which there is a requirement for glycine,this emphasises the value of so-called“non-essential”amino acids.Starch digestive dynamics and their possible impact of glucose on pancreatic secretions of insulin are discussed,although the functions of insulin in avian species require clarification.Maize is probably a superior feed grain to wheat as the basis of reduced-CP diets;if so,the identification of the underlying reasons for this difference should be instructive.Moderating increases in starch concentrations and condensing dietary starch:protein ratios in reduced-CP diets may prove to be advantageous as expanding ratios appear to be aligned to inferior broiler performance.Threonine is specifically examined because elevated free threonine plasma concentrations in birds offered reduced-CP diets may be indicative of compromised performance.If progress in these directions can be realised,then the prospects of reduced-CP diets contributing to sustainable chicken-meat production are promising.展开更多
Background: Limited research has focused on the effect of Lactobacillus on the intestinal toxicity of deoxynivalenol(DON).The present study was conducted to investigate the role of Lactobacillus plantarum(L.plantarum)...Background: Limited research has focused on the effect of Lactobacillus on the intestinal toxicity of deoxynivalenol(DON).The present study was conducted to investigate the role of Lactobacillus plantarum(L.plantarum) JM113 in protecting against the intestinal toxicity caused by DON.Methods: A total of 144 one-day-old healthy Arbor Acres broilers were randomly distributed into 3 treatments,including the CON(basal diet),the DON(extra 10 mg/kg deoxynivalenol),and the DL(extra 1 × 109 CFU/kg L.plantarum JM113 based on DON group) treatments.The growth performance,organ indexes,intestinal morphology,pancreatic digestive enzymes,intestinal secreted immunoglobulin A(sIgA),jejunal transcriptome,and intestinal microbiota were evaluated.Results: Compared with the CON and DL groups,the DON supplementation altered intestinal morphology,especially in duodenum and jejunum,where villi were shorter and crypts were deeper(P < 0.05).Meanwhile,the significantly decreased mRNA expression of jejunal claudin-1 and occludin(P < 0.05),ileal rBAT and jejunal GLUT1 of 21-day-old broilers(P < 0.05),as well as duodenal PepT1 and ileal rBAT of 42-day-old broilers were identified in the DON group.Moreover,supplementation with L.plantarum JM113 could increase duodenal expression of IL-10 and IL-12 of 21-dayold broilers,ileal s IgA of 42-day-old broilers,and the bursa of Fabricius index of 21-day-old broilers.Further jejunal transcriptome proved that the genes related to the intestinal absorption and metabolism were significantly reduced in the DON group but a significant increase when supplemented with extra L.plantarum JM113.Furthermore,the bacteria related to nutrient utilization,including the Proteobacteria,Escherichia,Cc-115(P < 0.05),Lactobacillus and Prevotella(P < 0.1) were all decreased in the DON group.By contrast,supplementation with L.plantarum JM113 increased the relative abundance of beneficial bacterium,including the Bacteroidetes,Roseburia,Anaerofustis,Anaerostipe,and Ruminococcus bromi(P < 0.05).Specifically,the increased abundance of bacteria in the DL group could be proved by the significantly increased caecal content of propionic acid,n-Butyric acid,and total short-chain fatty acid.Conclusions: L.plantarum JM113 enhanced the digestion,absorption,and metabolic functions of the gut when challenged with DON by reducing the injury to intestinal barriers and by increasing the abundance of beneficial bacterium.展开更多
基金supported by China Agriculture Research System Program(Project No.CARS-41-G04)。
文摘Background Necrotic enteritis(NE)in broiler chickens leads to significant economic losses in poultry production.This study examined the inhibitory effects of usnic acid and tannic acid on coccidia,sporozoite,and Clostridium perfringens and assessed their influence on growth performance and intestinal health in NE-challenged broilers through in vitro and in vivo experiments.Methods The in vitro experiment included 5 treatment groups:the negative control(NC),2μmol/L diclazuril(DZ),30μmol/L usnic acid(UA),90μmol/L tannic acid(TA),and 15μmol/L usnic acid^(+)45μmol/L tannic acid(UTA)groups.The in vivo experiment involved 320 broilers divided into four groups:PC(NE-challenged),SA(500 mg/kg salinomycin premix^(+)NE-challenged),UA(300 mg/kg usnic acid^(+)NE-challenged),and UTA(300 mg/kg usnic acid^(+)500 mg/kg tannic acid^(+)NE-challenged)groups.Results In the in vitro study,the UA,TA,and UTA treatments significantly increased apoptosis in coccidian oocysts and sporozoites,lowered the mitochondrial membrane potential(P<0.05),and disrupted the oocyst structure compared with those in the NC group.UA and TA had inhibitory effects on C.perfringens,with the strongest inhibition observed in the UTA group.The in vivo results demonstrated that the SA group presented significantly improved growth performance on d 13,21,and 28(P<0.05),whereas the UA and UTA groups presented improvements on d 13 and 21(P<0.05).The SA,UA,and UTA treatments reduced the intestinal lesion scores by d 28 and the fecal coccidian oocyst counts from d 19 to 21(P<0.05).Compared with the PC group,the UA and UTA groups presented lower intestinal sIgA levels and CD8^(+)cell percentages(P<0.05),with a trend toward a reduced CD3^(+)cell percentage(P=0.069).The SA,UA,and UTA treatments significantly reduced the serum diamine oxidase activity,crypt depth,and plateletderived growth factor levels in the intestinal mucosa while increasing the villus height to crypt depth ratio and number of goblet cells(P<0.05).The UTA treatment also significantly increased the acetate and butyrate concentrations in the cecum(P<0.05).With respect to the gut microbiota,significant changes inβdiversity in the ileum and cecum were observed in the SA,UA,and UTA groups,indicating that the microbial community compositions differed among the groups.Romboutsia dominated the SA group,Bacillales dominated the UA group,and Lactobacillales and Lachnospirales dominated the UTA group in the ileal microbiota.In the cecal microbiota,Lactobacillus,Butyricicoccus,and Blautia abundances were significantly elevated in the UTA group(P<0.05).Conclusion Usnic acid and tannic acid induce apoptosis in coccidia and sporozoites by lowering the mitochondrial membrane potential.Both usnic acid alone and in combination with tannic acid alleviate NE-induced adverse effects in broilers by modulating intestinal immunity,altering the microbial composition,and improving intestinal barrier function.Compared with usnic acid alone,the combination of usnic acid and tannic acid had superior effects,providing a promising basis for the development of effective feed additive combinations.
基金funded by the Australian Research Council Linkage Grant(LP220100292)in which Evonik Operations GmbH was the Linkage partner.
文摘Background Wheat and,to a lesser extent,sorghum are the dominant feed grains in Australian chicken-meat production.There is considerable local interest in the development of reduced-crude protein(CP)broiler diets in part because this would decrease the need to import soybean meal into the country.Maize is rarely included in Australian broiler diets,but birds appear better able to accommodate dietary CP reductions with maize than with wheat-based diets.Sorghum is more similar to maize than wheat and for this reason wheat-and sorghum-based diets,with standard and reduced-CP concentrations,were evaluated in broiler chickens in a direct comparison.Results Reducing dietary CP from 205 to 175 g/kg CP did not statistically influence weight gain and FCR in broilers offered sorghum-based diets from 14 to 35 d post-hatch.In contrast,the 30 g/kg CP reduction compromised weight gain by 10.1%(1,964 versus 2,187 g/bird)and FCR by 9.68%(1.575 versus 1.436),in broilers offered wheat-based diets.Consequently,treatment interactions(P<0.001)were observed for dietary CP levels grain type for both weight gain and FCR.Another treatment interaction(P<0.001)was observed for starch digestibility coefficients in the distal jejunum.Birds offered 205 g/kg CP,wheat-based diets had superior starch digestibility by 11.6%(0.914 versus 0.819),but sorghum supported superior starch digestibility by 9.70%(0.837 versus 0.763)in the context of 175 g/kg CP diets.Conclusions Under the condition of thid study,broiler chickens offered sorghum-based diets had a greater capacity to accommodate dietary CP reductions than their counterparts offered wheat-based diets.This study confirmed that wheat-based diets are not conducive to CP reductions,but the causal factors have yet to be identified precisely.
基金support for the project was provided by Chicken Farmers of Saskatchewan(424357)Canadian Poultry Research Council(424854)+1 种基金Natural Sciences and Engineering Research Council of Canada(424679)Saskatchewan Agriculture Development Fund(426954).
文摘Background Necrotic enteritis(NE)is an economically important disease of broiler chickens caused by Clostridium perfringens(CP).The pathogenesis,or disease process,of NE is still not clear.This study aimed to identify the alterations of metabolites and metabolic pathways associated with subclinical or clinical NE in CP infected birds and to investi-gate the possible variations in the metabolic profile of birds infected with different isolates of CP.Methodology Using a well-established NE model,the protein content of feed was changed abruptly before expos-ing birds to CP isolates with different toxin genes combinations(cpa,cpb2,netB,tpeL;cpa,cpb2,netB;or cpa,cpb2).Metabolomics analysis of jejunal contents was performed by a targeted,fully quantitative LC-MS/MS based assay.Results This study detected statistically significant differential expression of 34 metabolites including organic acids,amino acids,fatty acids,and biogenic amines,including elevation of butyric acid at onset of NE in broiler chickens.Subsequent analysis of broilers infected with CP isolates with different toxin gene combinations confirmed an eleva-tion of butyric acid consistently among 21 differentially expressed metabolites including organic acids,amino acids,and biogenic amines,underscoring its potential role during the development of NE.Furthermore,protein-metabolite network analysis revealed significant alterations in butyric acid and arginine-proline metabolisms.Conclusion This study indicates a significant metabolic difference between CP-infected and non-infected broiler chickens.Among all the metabolites,butyric acid increased significantly in CP-infected birds compared to non-infected healthy broilers.Logistic regression analysis revealed a positive association between butyric acid(coefficient:1.23,P<0.01)and CP infection,while showing a negative association with amino acid metabolism.These findings suggest that butyric acid could be a crucial metabolite linked to the occurrence of NE in broiler chickens and may serve as an early indicator of the disease at the farm level.Further metabolomic experiments using different NE animal models and field studies are needed to determine the specificity and to validate metabolites associated with NE,regardless of predisposing factors.
基金funded by the National Natural Science Foundation of China(No.32172774)the Key Research and Development and Promotion of Special(Science and Technology)Project of Henan Province(No.242102110018).
文摘Background It is important to promote intestinal development and maturation of chicks for feed digestion and utilization,intestinal health,and disease resistance.This study aimed to investigate the effects of dietary yeast cell wall polysaccharides(YCWP)addition on intestinal development and maturation of chickens and its potential action mechanism.Methods 180 one-day-old male Arbor Acres broilers were randomly assigned to three groups containing control(basal diets without any antibiotics or anticoccidial drug),bacitracin methylene disalicylate(BMD)-treated group(50 mg/kg)and YCWP-supplemented group(100 mg/kg).Results Compared with control group,in-feed antibiotic BMD continuous administration significantly decreased crypt depth(d 21)and villus height(d 42)along with mucosal maltase activity(d 42)in the ileum(P<0.05).Also,BMD markedly downregulated gene expression levels ofβ-catenin,lysozyme,occludin and FABP-2(d 21)and innate immune related genes CD83 and MHC-I mRNA levels(d 42,P<0.05),and decreased goblet cell counts in the ileum of chickens(d 21 and d 42,P<0.05).While,TLR-2,TLR-6 and iNOS mRNA abundances were notably upregulated by BMD treatment(d 42,P<0.05).Nevertheless,dietary YCWP addition significantly increased the ratio of villus height to crypt depth(d 21),villus surface area(d 21 and d 42),ileal alkaline phosphatase and maltase activities as well as goblet cell(d 21 and d 42)and IgA-producing plasma cell numbers as compared to BMD treatment(d 21,P<0.05).YCWP addition also upregulated gene expression levels of Lgr5,Wnt/β-catenin signaling pathway related gene(Wnt3,β-catenin,d 21;β-catenin,d 42),intestinal cells proliferation marker Ki-67 and barrier function related genes(occludin,d 21 and d 42,P<0.05).Moreover,YCWP significantly increased antigen presenting cell marker related genes(MHC-II,d 21;CD83 and MHC-I,d 42),TLR-1,TLR-2 and TLR-6 mRNA levels(d 21,P<0.05).Cecal microbiome analysis showed that YCWP addition obviously improved cecal microbial composition,as indicated by increasing relative abundance of Fournierella,Psychrobacter and Ruminiclostridium on d 21,and Alistipes and Lactobacillus on d 42,which were positively related with gut development and maturation related indexes(P<0.05).Conclusion Collectively, YCWP promoted yet antibiotic BMD delayed intestinal morphological and immunologicaldevelopment linked with modulating gut microbiome in chickens.
基金supported by the National Key Research and Development Program(2016YFD0501303).
文摘The development of alternative therapies to treat chicken coccidiosis has become a hot topic because of the widespread use of conventional medicines.This study aimed to investigate the effectiveness of eugenol in treating Eimeria tenella infection in broilers.Broiers,at the age of 14 d,were orally infected with sporulated Eimeria tenella oocysts,and then,eugenol essential oil was added to chicken feed at three different dosages(0.1,0.2 or 0.4 g/kg).The anticoccidial effects of eugenol essential oil were assessed using the anticoccidial index(ACI).As a result,eugenol exhibited a moderate anticoccidial effect,with an ACI of 167.37 at 0.2 g/kg.After eugenol treatment,the expression of occludin in the epithelial cells of the chicken cecum was significantly greater(P<0.05)than that in the epithelial cells of the nontreated control(IC)group.The proportion of intestinal Lactobacillus_agilli increased.Eugenol therapy dramatically increased the activity of superoxide dismutase.After high-dose treatment,the expression of the proinflammatory factors IL-1βand IL-6 significantly decreased,while the expression of the cytokines IL-4 and IFN-γsignificantly increased.The safety of eugenol essential oil was evaluated at the 1,3 or 6 recommended doses.Overall,no significant differences were detected in the blood tests or serum biochemistry of the chickens between the treatment groups and the control group.As a result,eugenol essential oil can cure chicken coccidiosis by improving the intestinal microbial structure in the chicken cecum and decreasing the cecum's inflammatory reactions,thus strengthening immune function and eventually demonstrating anticoccidial properties.
基金supported by the Earmarked fund for China Agriculture Research System of MOF and MARA(Grant No.CARS-41-G01).
文摘Background Salmonella enterica serovar Enteritidis(S.Enteritidis)is a global foodborne pathogen that poses a significant threat to human health,with poultry being the primary reservoir host.Therefore,addressing S.Enteritidis infections in poultry is crucial to protect human health and the poultry industry.In this study,we investigated the effect of co-housing Arbor Acres(AA)chickens,a commercial breed susceptible to S.Enteritidis,with Tibetan chickens,a local breed resistant to S.Enteritidis infection,on the resistance of the latter to the pathogen.Results Ninety-six 1-day-old Tibetan chickens and 961-day-old AA chickens were divided into a Tibetan chicken housed alone group(n=48),an AA chicken housed alone group(n=48),and a co-housed group(48 birds from each breed for 2 cages).All birds were provided the same diet,and the experimental period lasted 14 d.At d 7,all chickens were infected with S.Enteritidis,and samples were collected at 1-,3-,and 7-day-post-infection.We found that the body weight of AA chickens significantly increased when co-housed with Tibetan chickens at 1-and 3-day-post-infection(P<0.05).In addition,the cecal S.Enteritidis load in AA chickens was significantly reduced at 1-,3-,and 7-day-post-infection(P<0.05).Furthermore,the inflammatory response in AA chickens decreased,as evidenced by the decreased expression of proinflammatory cytokines NOS2,TNF-α,IL-8,IL-1β,and IFN-γin their cecal tonsils(P<0.05).Co-housing with Tibetan chickens significantly increased the height of villi and number of goblet cells(P<0.05),as well as the expression of claudin-1(P<0.05),a tight junction protein,in the jejunum of AA chickens.Further analysis revealed that co-housing altered the gut microbiota composition in AA chickens;specifically,the relative abundances of harmful microbes,such as Intestinimonas,Oscillibacter,Tuzzerella,Anaerotruncus,Paludicola,and Anaerofilum were reduced(P<0.05).Conclusions Our findings indicate that co-housing with Tibetan chickens enhanced the resistance of AA chickens to S.Enteritidis infection without compromising the resistance of Tibetan chickens.This study provides a novel approach for Salmonella control in practical poultry production.
基金supported by the National Natural Science Foundation of China-Henan Joint Grant(U1804107)the Zhongyuan Youth Talent Support Program,China(ZYYCYU202012156)the ProgramforScience&Technology Innovation Talents in Universities of Henan Province,China(22HASTIT038).
文摘Previous studies have shown that VGLL2,a member of the mammalian Vestigial-like(VGLL)family,plays important roles in the growth and development of animal skeletal muscle,but its specific role in the development of chicken skeletal muscle is unclear.The main goal of this study was to explore the biological functions of VGLL2 in the development of chicken skeletal muscle and the proliferation and differentiation of skeletal muscle cells in vitro.In this study,we detected the effect of VGLL2 on the proliferation of myoblasts by CCK8,EdU and flow cytometry analyses after overexpressing and interfering with VGLL2.Indirect immunofluorescence was used to detect the effect of VGLL2 on the differentiation of myoblasts.qRT-PCR and hematoxylin and eosin(H&E)staining were used to evaluate the effects of VGLL2 overexpression on the growth rate and muscle fiber structure of chicken skeletal muscle.The results showed that VGLL2 inhibited the proliferation of primary cultured chicken myoblasts and promoted the differentiation of these cells.Interestingly,food intake and muscle fiber development were significantly enhanced by the overexpression of VGLL2 in chickens.Taken together,these data demonstrate that the VGLL2 gene may be a useful marker for improving muscle mass in poultry.
文摘Background Black soldier fly larvae meal(BSFLM)stands out as a promising nutritional resource due to its rich bioactive substances and favorable protein profile.Nonetheless,its potential to mitigate coccidia infection in broilers remains uncertain.This study aimed to evaluate the impact of partially defatted BSFLM(pBSFLM)on growth performance,nutrient utilization,and intestinal health,focusing on morphology,immunology,and cecal fermentation in coccidia-infected broilers.Methods Over the initial 13 d,480 newly-hatched Cobb 500 male birds were allocated to three diets with increasing pBSFLM concentrations(0,60,or 120 g/kg).At d 13 post hatching,chicks within each dietary group were further allotted to non-challenge or challenge subsets,generating six treatments in a 3×2 factorial arrangement.Challenged birds were orally administered oocysts of E.maxima,E.acervulina,and E.tenella(25,000:125,000:25,000).Results During the infection phase(d 13 to 19),linear interactions between Eimeria and pBSFLM were observed in gain to feed ratio(G:F)(P<0.05)and cecal interferon-γ(IFN-γ,P<0.05),with a tendency in cecal acetate concentration(P=0.06).A quadratic interaction was observed in crypt depth(CD,P<0.05).Incremental pBSFLM inclusion negatively affected G:F,CD,IFN-γ,and acetate productions in the ceca under coccidia challenge.Conversely in nonchallenged birds,the impact of pBSFLM varied from neutral(e.g.G:F)to potentially advantageous(e.g.acetate).Challenged birds exhibited decreased(P<0.01)BW,BW gain,feed intake(FI),and the apparent ileal digestibility and total tract nutrient utilization of DM,gross energy,and nitrogen(N).Eimeria challenge reduced(P<0.01)serum carotenoid concentrations,decreased the villus height to crypt depth ratio(VH:CD,P<0.01),and increased concentrations of branched-chain fatty acids,specifically isobutyrate(P=0.059)and isovalerate(P<0.05)in the cecum.Dietary pBSFLM addition linearly reduced(P<0.05)BW,FI,and N utilization.Tendencies(P<0.06)were observed where pBSFLM linearly decreased VH:CD and reduced goblet cell density.Conclusions Increasing pBSFLM supplementation,particularly at 12%,adversely affected growth,ileal morphology,cecal acetate production,and downregulated key cytokine expression in response to coccidia infection.
基金supported by the National Natural Science Foundation of China (32273010 and 31972681)the National Key Research and Development Program of China (2017YFD0501500)。
文摘Mycoplasma gallisepticum(MG) is a common avian pathogen that mainly infects poultry, causingsignificant reductions in body weight gain and egg production, along with damage to immune organs andimmunosuppression. MG is susceptible to co-infections with other pathogens, leading to increased mortalityrates and significant economic losses in the global poultry industry. While antibiotics have been extensivelyapplied worldwide to treat MG infections in poultry production, concerns regarding antibiotic resistanceand residue remain prevalent. Traditional Chinese medicine(TCM), renowned for its natural, safe, andnon-toxic properties, has shown significant anti-inflammatory and immune-enhancing effects. This studyaimed to investigate the protective effect of TCM on production performance and its impact on MG-inducedimmunosuppression through the MAPK/ERK/JNK signaling pathway in chickens. Our results showed that TCMalleviated the negative effects of MG infection on production performance, as evidenced by improvements inbody weight gain, feed conversion rate, survival rate, and immune organ index. TCM exhibited direct inhibitionof the MG proliferation in vitro and in vivo. Furthermore, TCM treatment promoted the normalization of tracheaand lung tissue structure in MG-infected chickens, leading to a significant reduction in inflammatory damage.Moreover, following the treatment with the TCM, the production of pro-inflammatory cytokines interleukin-1β(IL-1β) and tumor necrosis factor-α(TNF-α) decreased significantly, accompanied by the downregulation of pro-apoptotic genes caspase3, caspase9, and BAX, both in vitro and in vivo. A mechanism-based study showed that in vitro and in vivo treatment with the TCM significantly reduced the expression of key proteins, including early growth response gene 1(EGR1), p-ERK, p-JNK, and p-JUN. Altogether, TCM improved body weight gain, inhibited pro-inflammation responses, and alleviated tissue damage by inhibiting the MAPK/ERK/JNK signaling pathway to protect the performance and immune system of MG-infected chickens.
基金Supported by China Postdoctoral Science Foundation(20100470565)Science and Technology Support Program of Hebei Province(10960408D)+1 种基金Project of Science and technology Bureau of Shijiazhuang(1150093A)Science and Technology Development Project of Qinhuangdao City(201101A182)~~
文摘[Objective] This study aimed to investigate the outer membrane protein （OMP） patterns of Escherichia coli 038, 053 and 075 isolates from chickens. [Method] Eight pathogenic E. coil isolates with various serotypes were used as experimental materials to extract OMP by using supersonic schizolysis method and Sarcosyl. After SDS-PAGE electrophoresis, OMP patterns of the extracted products were determined based on the OMP model diagram. [Result] OMP of eight E. coil isolates with three serotypes were divided into three patterns, to be specific, 2 075 isolates respectively belonged to OMP-I and OMP-II pattern, 1 053 isolate belonged to OMP-II pattern, and 5 038 isolates belonged to OMP-I and OMP-III pattern. [Conclusion] Experimental results showed that E. coli isolates with the same serotype may belong to completely different OMP patterns, while serologically unrelated isolates may belong to the same OMP pattern. OMP of E. coil isolates with the same serotype may generate genetic differentiation; in addition, OMP of E. coli isolates with different serotypes may have different genetic correlation.
基金The National Special Fund for Agro-Scientific Research in the Public Interest(20140304–07)the National Broiler Industry Technology Project(No.31072049)supported this study
文摘Background: The poultry industry is in need of effective antibiotic alternatives to control outbreaks of necrotic enteritis(NE) due to Clostridium perfringens.Methods: This study was conducted to investigate the effects of feeding Bacil us coagulans on the growth performance and gut health of broiler chickens with C. perfringens-induced NE. Two hundred and forty 1-day-old broiler chicks were randomly assigned to a 2 × 2 factorial arrangement with two dietary B. coagulans levels(0 or 4 × 109 CFU/kg of diet) and two disease chal enge statuses(control or NE chal enged).Results: NE-induced reduction in body weight gain was relieved by the addition of B. coagulans into broiler diets compared with the NE-infected birds. NE infection damaged intestinal morphological structure, promoted intestinal C.perfringens growth and liver invasion, and enhanced anti-C. perfringens specific sI gA concentrations in the gut and specific IgG levels in serum compared with the uninfected birds. NE infection significantly(P < 0.05) decreased mucin-2(at 14 d post-infection(DPI), tol-like receptor 2(TLR2, at 7 and 14 DPI), TLR4(at 7 and 14 DPI), tumor necrosis factor super family15(TNFSF15, at 7 and 14 DPI), lysozyme(LYZ, at 14 DPI) and fowlicidin-2(at 7 and 14 DPI) mR NA levels, whereas it dramatical y(P = 0.001) increased IFN-γ mR NA levels at 7 DPI. However, chal enged birds fed diets supplemented with B.coagulans showed a significant(P < 0.01) decrease in gut lesion scores, decreased C. perfringens numbers in the cecum and liver, and an increase in fowlicidin-2 mR NA levels in compared with the uninfected birds. In addition, compared with the non-supplemented group, dietary inclusion of B. coagulans improved intestinal barrier structure, further increased specific sI gA levels and alkaline phosphatase(IAP) activity in the jejunum, enhanced the expression of jejunum lysozyme mR NA, and inhibited the growth, colonization, and invasion of C. perfringens; in contrast, it reduced serum-specific IgG concentrations and jejunum IFN-γ mR NA levels.Conclusion: These results indicated that dietary B. coagulans supplementation appeared to be effective in preventing the occurrence and reducing the severity of C. perfringens-induced NE in broiler chickens.
基金Supported by Special Fund for the Construction of Modern Agricultural Industry Technology System(nycytx-42-Z02)Special Fund for Science,Technology and Innovation Capacity Building of Beijing Academy of Agriculture and Forestry Sciences(KJCX20140105)Youth Science Fund Project of National Natural Science Foundation of China(31001004)~~
文摘[Objective] This study aimed to investigate influencing factors and variation trends of muscle p H in chickens after slaughter. [Method] Beijing You chickens and Lohmann brown chickens were reared under the same conditions and slaughtered at the age of 8, 16 and 20 weeks, respectively. At different time（15 min, 1, 4, 8,12, 24 and 48 h） after slaughter, p H value of breast muscles and leg muscles was measured. [Result] The results showed that muscle position, post-slaughter time,gender and week age were important factors influencing p H value, but the breed had little effect. Within 1 h after slaughter, p H value of breast muscles and leg muscles declined rapidly, which reached the minimum level at 12 h after slaughter,and then increased slowly. In addition, p H value of leg muscles exhibited higher decline and increase rates than that of breast muscles to some extent. [Conclusion]This study provided basis for breeding of chickens with excellent meat quality.
基金supported by University of Torino(Italy)founding:SCHA_RILO_14_01(2015–2017)and SCHA_RILO_16_02(2016–2018)
文摘Background: The present study has evaluated the effects of different inclusion levels of a partially defatted black soldier fly(Hermetia illucens L.; HI) larva meal on the growth performance, blood parameters and gut morphology of broiler chickens. A total of 256 male broiler chickens(Ross 308) were reared from d 1 to d 35 and assigned to4 dietary treatments(8 replicates/treatment and 8 birds/replicate). HI larva meal was included at increasing levels(0, 5%, 10% and 15%; HI0, HI5, HI10 and HI15, respectively) in isonitrogenous and isoenergetic diets formulated for 3 feeding phases: starter(1–10 d), growing(10–24 d) and finisher(24–35 d). Two birds per pen were slaughtered at d 35 and morphometric investigations and histopathological alterations were performed.Results: The live weight(LW) showed linear and quadratic responses to increasing HI larva meal(maximum for HI10 group). Average daily gain(ADG) showed a linear and quadratic responses to HI meal(maximum for HI10 group) during starter and growing periods. A linear decrease was observed for ADG during the finisher period. The daily feed intake(DFI) showed a linear and quadratic effect during the starter period(maximum for HI10 group).Linear and quadratic responses were observed for the feed conversion ratio(FCR) in the growing period and for the whole period of the experiment. The FCR showed a linear response in the finisher period(maximum for HI15).No significant effects were observed for the blood and serum parameters, except for the phosphorus concentration,which showed linear and quadratic responses as well as glutathione peroxidase(GPx) activity, the latter of which showed a linear response. The HI15 birds showed a lower villus height, a higher crypt depth and a lower villus height-to-crypt depth ratio than the other groups.Conclusions: Increasing levels of dietary HI meal inclusion in male broiler chickens may improve the LW and DFI during the starter period, but may also negatively affect the FCR and gut morphology, thus suggesting that low levels may be more suitable. However, no significant effects on the haematochemical parameters or histological findings were observed in relation to HI meal utilization.
基金This work was supported by "948" Project of China (No. 2001-361), Chinese National Programs for High Technology Research and Development (No. 2004AA222170), and Key Project of Chinese National Programs for Fundamental Research and Develop-ment (No. G2000016103).
文摘Genetic polymorphism of the major histocompatibility complex （MHC） B-LBⅡ gene was studied by amplification of exon 2 using PCR, followed by cloning and DNA sequencing in eight indigenous Chinese chicken populations. To reveal the genetic variation of the B-LB Ⅱ gene, 37 types of patterns detected by PCR-SSCP were investigated first, which would be used to screen novel B-LB Ⅱsequences within the breeds. The types of PCR-SSCP patterns and final sequencing allowed for the identification of 31 novel MHC B-LBⅡ alleles from 30 unrelated individuals of Chinese chickens that were sampled. These are the first designators for the alleles of chicken MHC B-LBⅡ gene based on the rule of assignment for novel mammalian alleles. Sequence alignment of the 31 B-LB Ⅱ alleles revealed a total of 68 variable sites in the fragment of exon 2, of which 51 parsimony informative and 17 singleton variable sites were observed. Among the polymorphic sites, the nucleotide substitutions in the first and second positions of the codons accounted for 36.76% and 35.29%, respectively. The sequence similarities between the alleles were estimated to be 90.6%-99.5%. The relative frequencies of synonymous and nonsynonymous nucleotide substitutions within the region were 2.92%±0.94% and 14.64%±2.67%, respectively. These results indicated that the genetic variation within exon 2 appeared to have largely arisen by gene recombination and balancing selection. Alignment of the deduced amino acid sequences of the β1 domain coded by exon 2 revealed 6 synonymous mutations and 27 nonsynonymous substitutions at the 33 disparate sites. In particular, the nonsynonymous substitutions at the putative peptide-binding sites are considered to be associated with immunological specificity of MHC B-LB Ⅱ molecule in Chinese native chickens. These results can provide a molecular biological basis for the study of disease resistance in chicken breeding.
基金supported by the International Cooperation Project of Zhejiang Province(No.2012C14031)Innovative Research Team Program of Zhejiang Province(No.2011R50025)
文摘Background： Colibacillosis caused by enterotoxigenic Escherichia coil （E. coil} results in economic losses in the poultry industry. Antibiotics are usually used to control colibacillosis, however, E. coli has varying degrees of resistance to different antibiotics. Therefore the use of probiotics is becoming accepted as an alternative to antibiotics. In this study, we evaluated the effects of Clostfidium butyricum （C. butyficum） on growth performance, immune response, intestinal barrier function, and digestive enzyme activity in broiler chickens challenged with Eschefichia coli （E. coil） K88. Methods： The chickens were randomly divided into four treatment groups for 28 days. Negative control treatment （NC） consisted of birds fed a basal diet without E. coil K88 challenge and positive control treatment （PC） consisted of birds fed a basal diet and challenged with E. coil K88. C. buO/ricum probiotic treatment （CB） consisted of birds fed a diet containing 2 x 107 cfu C. buO/ricum/kg of diet and challenged with E. coil K88. Colistin sulfate antibiotic treatment （CS） consisted of birds fed a diet containing 20 mg colistin sulfate/kg of diet and challenged with E. coil K88. Results： The body weight （BW） and average day gain （ADG） in the broilers of CB group were higher （P 〈 0.05） than the broilers in the PC group overall except the ADG in the 14-21 d post-challenge. The birds in CB treatment had higher （P 〈 0.05） concentration of tumor necrosis factor-a （TNF-a） at 3 and 7 d post-challenge, and higher （P 〈 0.05） concentration of interleukin-4 （IL-4） at 14 d post-challenge than those in the PC treatment group. The concentration of serum endotoxin in CB birds was lower （P 〈 0.05） at 21 d post-challenge, and the concentrations of serum diamine oxidase in CB birds were lower （P 〈 0.05） at 14 and 21 d post-challenge than in PC birds. Birds in CB treatment group had higher （P 〈 0.05） jejunum villi height than those in PC, NC, or CS treatment at 7, 14, and 21 d post-challenge. In comparison to PC birds, the CB birds had lower （P 〈 0.05） jejunum crypt depth during the whole experiment. The birds in CB or CS treatment group had higher （P 〈 0.05） activities of amylase and protease at 3, 7, and 14 d post-challenge, and higher （P 〈 0.05） activity of lipase at 3, 7 d post-challenge than PC birds.
基金supported by National Natural Science Foundation of China(No.31772620)China Agricultural Research System Poultry-related Science and Technology Innovation Team of Peking(BAIC 04-2018)
文摘Background: There is growing interest in carbohydrate and protein nutrition to enhance the efficiency of animal production.Reduced-crude protein diets depress environmental pollution and feeding cost,but the challenge to their adoption is maintaining digestive function and growth performance of birds.The present study was conducted to evaluate the influence of different dietary starch sources and protein levels on intestinal functionality and mucosal amino acid catabolism.Methods: Six dietary treatments,based on maize and soybean meal,were offered to 360 AA+male chicks from 6 to 35 d post-hatch as a 3 × 2 factorial array.Either waxy rice or amylose was added to a conventional maize-soy diet to provide three sources of starch with different digestion rates and relatively high and low dietary protein levels.Growth performance,parameters of intestinal functionality and concentrations of free amino acid in the portal circulation were determined.Results: In the grower phase,starch source influenced(P < 0.02) weight gain as diets containing amylose supported significantly higher weight gains than waxy rice.Significant increase of ileal ATP concentrations and Na^+/K^+-ATPase activity were found in amylose treatment.Also,amylose decreased BrdU positive cell numbers and down-regulated m RNA expression for CASP-3.GOT activity in the ileum was higher(P < 0.01) in birds offered low protein diets and there was a trend(P = 0.057) for waxy rice as a starch source to increase ileal GOT activities.There was a significant influence on the concentration of seventeen amino acids in the portal circulation with tryptophan the one exception.Waxy rice as a starch source generated 13.6% and 22.4% numerically higher concentrations of non-essential amino acids than maize and amylose,respectively.Conclusions: Amino acid catabolism in the gut mucosa is subject to nutritional regulation.Given that amino acids can be spared from catabolism in the gut mucosa by supplementation of amylose,it follows their post-enteral availability would be improved and intestinal energy would be derived more efficiently from glucose.
基金supported by Novus International Company(Missouri,USA)the earmarked fund for China Agricultural Research Systems(CARS-42)
文摘Background： In the post-antibiotic era, essential oils （EO） are promising alternatives to growth-promoting antibiotics. The aim of the present study was to investigate the antibacterial activities of an EO product and its components thymol and carvacrol in vitro, and the efficacy of EO to control Clostridium perffingens challenge in broiler chickens. Results： The in vitro minimum inhibitory concentration assay showed strong antibacterial activity of the EO product, thymol, and carvacrol against pathogenic Escherichia col~, C. perffingens, and Salmonella strains, and weak activity towards beneficial Lactobacillus strains. Besides, an additive effect was observed between thymol and carvacrol. The in vivo study was carried out with 448 male broiler chicks following a 4 x 2 factorial arrangement to test the effects of EO supplementation （0, 60, 120, or 240 mg/kg EO in wheat-based diet）, pathogen challenge （with or without oral gavage of C. perfr/ngens from day 14 to day 20） and their interactions. Each treatment consisted of eight replicate pens （seven birds/pen）. The challenge led to macroscopic gut lesions, and resulted in a significant increase in ileal populations of C. perffingens and Eschefichia subgroup （P ≤ 0.05） on day 21. Dietary EO supplementation did not influence C. perfringens numbers, but linearly alleviated intestinal lesions on day 21 and 28 （P= 0.010 and 0.036, respectively）, and decreased Eschefichia populations in ileum with increased EO dosages （P = 0.027 and 0.071 for day 21 and 28, respectively）. For caecum, EO quadratically influenced Lactobacillus populations on day 21 （P = 0.002）, and linearly decreased the numbers of total bacteria and Eschefichio on day 28 （P = 0.026 and 0.060, respectively）. Mean thymol and carvacrol concentrations in the small intestine were 0.21 and 0.20 μg/g in intestinal digesta （wet weight）, respectively, for birds fed 60 mg/kg EO, and 0.80 and 0.71 μg/g, respectively, for birds fed 240 mg/kg EO. Conclusions： These results indicated that dietary EO supplementation could affect intestinal microbiota and alleviate intestinal lesions in broilers, which may contribute in controlling C. perffingens infection in broiler chickens.
基金supported by the National Key Research and Development Program of China(2021YFD1800200)the Laboratory for Lingnan Modern Agriculture Project(NT2021007)the China Agriculture Research System of the MOF and MARA(CARS-41-G12)。
文摘Some H5 viruses isolated in poultry or wild birds between 2020 and 2021 were found to be antigenically different from the vaccine strains(H5-Re11 and H5-Re12) used in China. In this study, we generated three new recombinant vaccine seed viruses by using reverse genetics and used them for vaccine production. The vaccine strain H5-Re13 contains the hemagglutinin(HA) and neuraminidase(NA) genes of an H5 N6 virus that bears the clade 2.3.4.4 h HA gene, H5-Re14 contains the HA and NA genes of an H5 N8 virus that bears the clade 2.3.4.4 b HA gene, and H7-Re4 contains the HA and NA genes of H7 N9 virus detected in 2021. We evaluated the protective efficacy of the novel H5/H7 trivalent inactivated vaccine in chickens, ducks, and geese. The inactivated vaccine was immunogenic and induced substantial antibody responses in the birds tested. Three weeks after vaccination, chickens were challenged with five different viruses detected in 2020 and 2021: three viruses(an H5 N1 virus, an H5 N6 virus, and an H5 N8 virus) bearing the clade 2.3.4.4 b HA gene, an H5 N6 virus bearing the clade 2.3.4.4 h HA gene, and an H7 N9 virus. All of the control birds shed high titers of virus and died within 4 days post-challenge, whereas the vaccinated chickens were completely protected from these viruses. Similar protective efficacy against H5 viruses bearing the clade 2.3.4.4 h or 2.3.4.4 b HA gene was observed in ducks and geese. Our study indicates that the newly updated H5/H7 vaccine can provide solid protection against the H5 and H7 N9 viruses that are currently circulating in nature.
文摘The prime purpose of this review is to explore the pathways whereby progress towards reduced-crude protein(CP)diets and sustainable chicken-meat production may be best achieved.Reduced-CP broiler diets have the potential to attenuate environmental pollution from nitrogen and ammonia emissions;moreover,they have the capacity to diminish the global chicken-meat industry’s dependence on soybean meal to tangible extents.The variable impacts of reduced-CP broiler diets on apparent amino acid digestibility coefficients are addressed.The more accurate identification of amino acid requirements for broiler chickens offered reduced-CP diets is essential as this would diminish amino acid imbalances and the deamination of surplus amino acids.Deamination of amino acids increases the synthesis and excretion of uric acid for which there is a requirement for glycine,this emphasises the value of so-called“non-essential”amino acids.Starch digestive dynamics and their possible impact of glucose on pancreatic secretions of insulin are discussed,although the functions of insulin in avian species require clarification.Maize is probably a superior feed grain to wheat as the basis of reduced-CP diets;if so,the identification of the underlying reasons for this difference should be instructive.Moderating increases in starch concentrations and condensing dietary starch:protein ratios in reduced-CP diets may prove to be advantageous as expanding ratios appear to be aligned to inferior broiler performance.Threonine is specifically examined because elevated free threonine plasma concentrations in birds offered reduced-CP diets may be indicative of compromised performance.If progress in these directions can be realised,then the prospects of reduced-CP diets contributing to sustainable chicken-meat production are promising.
基金funded by the National Key R&D Program of China(2018YFD0500600 to Xin Yang)National Natural Science Foundation of China(No.31402095 to Xin Yang)+1 种基金the National Key R&D Program of China(2017YFD0500500 to Xiaojun Yang)the Program for Shaanxi Science&Technology(2017ZDXM-NY-087 to Xin Yang,2017TSCXL-NY-04-04 to Xiaojun Yang)
文摘Background: Limited research has focused on the effect of Lactobacillus on the intestinal toxicity of deoxynivalenol(DON).The present study was conducted to investigate the role of Lactobacillus plantarum(L.plantarum) JM113 in protecting against the intestinal toxicity caused by DON.Methods: A total of 144 one-day-old healthy Arbor Acres broilers were randomly distributed into 3 treatments,including the CON(basal diet),the DON(extra 10 mg/kg deoxynivalenol),and the DL(extra 1 × 109 CFU/kg L.plantarum JM113 based on DON group) treatments.The growth performance,organ indexes,intestinal morphology,pancreatic digestive enzymes,intestinal secreted immunoglobulin A(sIgA),jejunal transcriptome,and intestinal microbiota were evaluated.Results: Compared with the CON and DL groups,the DON supplementation altered intestinal morphology,especially in duodenum and jejunum,where villi were shorter and crypts were deeper(P < 0.05).Meanwhile,the significantly decreased mRNA expression of jejunal claudin-1 and occludin(P < 0.05),ileal rBAT and jejunal GLUT1 of 21-day-old broilers(P < 0.05),as well as duodenal PepT1 and ileal rBAT of 42-day-old broilers were identified in the DON group.Moreover,supplementation with L.plantarum JM113 could increase duodenal expression of IL-10 and IL-12 of 21-dayold broilers,ileal s IgA of 42-day-old broilers,and the bursa of Fabricius index of 21-day-old broilers.Further jejunal transcriptome proved that the genes related to the intestinal absorption and metabolism were significantly reduced in the DON group but a significant increase when supplemented with extra L.plantarum JM113.Furthermore,the bacteria related to nutrient utilization,including the Proteobacteria,Escherichia,Cc-115(P < 0.05),Lactobacillus and Prevotella(P < 0.1) were all decreased in the DON group.By contrast,supplementation with L.plantarum JM113 increased the relative abundance of beneficial bacterium,including the Bacteroidetes,Roseburia,Anaerofustis,Anaerostipe,and Ruminococcus bromi(P < 0.05).Specifically,the increased abundance of bacteria in the DL group could be proved by the significantly increased caecal content of propionic acid,n-Butyric acid,and total short-chain fatty acid.Conclusions: L.plantarum JM113 enhanced the digestion,absorption,and metabolic functions of the gut when challenged with DON by reducing the injury to intestinal barriers and by increasing the abundance of beneficial bacterium.
