Background Zinc glycine chelate(Zn-Gly)has anti-inflammation and growth-promoting properties;however,the mechanism of Zn-Gly contribution to gut barrier function in Cherry Valley ducks during intestinal inflammation i...Background Zinc glycine chelate(Zn-Gly)has anti-inflammation and growth-promoting properties;however,the mechanism of Zn-Gly contribution to gut barrier function in Cherry Valley ducks during intestinal inflammation is unknown.Three-hundred 1-day-old ducks were divided into 5 groups(6 replicates and 10 ducks per replicate)in a completely randomized design:the control and dextran sulfate sodium(DSS)groups were fed a corn-soybean meal basal diet,and experimental groups received supplements of 70,120 or 170 mg/kg Zn in form of Zn-Gly.The DSS and treatment groups were given 2 mL of 0.45 g/mL DSS daily during d 15–21,and the control group received normal saline.The experiment lasted 21 d.Results Compared with DSS group,70,120 and 170 mg/kg Zn significantly increased body weight(BW),villus height and the ratio of villus to crypt,and significantly decreased the crypt depth of jejunum at 21 d.The number of goblet cells in jejunal villi in the Zn-Gly group was significantly increased by periodic acid-Schiff staining.Compared with control,the content of intestinal permeability marker D-lactic acid(D-LA)and fluxes of fluorescein isothiocyanate(FITC-D)in plasma of DSS group significantly increased,and 170 mg/kg Zn supplementation significantly decreased the D-LA content and FITC-D fluxes.Compared with control,contents of plasma,jejunum endotoxin and jejunum pro-inflammatory factors IL-1β,IL-6 and TNF-αwere significantly increased in DSS group,and were significantly decreased by 170 mg/kg Zn supplementation.Dietary Zn significantly increased the contents of anti-inflammatory factors IL-10,IL-22 and sIgA and IgG in jejunum.Real-time PCR and Western blot results showed that 170 mg/kg Zn supplementation significantly increased mRNA expression levels of CLDN-1 and expression of OCLN protein in jejunum,and decreased gene and protein expression of CLDN-2 compared with DSS group.The 120 mg/kg Zn significantly promoted the expressions of IL-22 and IgA.Dietary Zn-Gly supplementation significantly decreased pro-inflammatory genes IL-8 and TNF-αexpression levels and TNF-αprotein expression in jejunum.Additionally,Zn significantly reduced the gene and protein expression of TLR4,MYD88 and NF-κB p65.Conclusions Zn-Gly improved duck BW and alleviated intestinal injury by regulating intestinal morphology,barrier function and gut inflammation-related signal pathways TLR4/MYD88/NF-κB p65.展开更多
Rivers are important habitats for wintering waterbirds.However,they are easily influenced by natural and human activities.An important approach for waterbirds to adapt to habitats is adjusting the activity time and en...Rivers are important habitats for wintering waterbirds.However,they are easily influenced by natural and human activities.An important approach for waterbirds to adapt to habitats is adjusting the activity time and energy expenditure allocation of diurnal behavior.The compensatory foraging hypothesis predicts that increased energy expenditure leads to longer foraging time,which in turn increases food intake and helps maintain a constant energy balance.However,it is unclear whether human-disturbed habitats result in increased energy expenditure related to safety or foraging.In this study,the scan sample method was used to observe the diurnal behavior of the wintering Spot-billed Duck(Anas poecilorhyncha) in two rivers in the Xin’an River Basin from October 2021 to March 2022.The allocation of time and energy expenditure for activity in both normal and disturbed environments was calculated.The results showed that foraging accounted for the highest percentage of time and energy expenditure.Additionally,foraging decreased in the disturbed environment than that in the normal environment.Resting behavior showed the opposite trend,while other behaviors were similar in both environments.The total diurnal energy expenditure of ducks in the disturbed environment was greater than that in the normal environment,with decreased foraging and resting time percentage and increased behaviors related to immediate safety(swimming and alert) and comfort.These results oppose the compensatory foraging hypothesis in favor of increased security.The optimal diurnal energy expenditure model included river width and water depth,which had a positive relationship;an increase in either of these two factors resulted in an increase in energy expenditure.This study provides a better understanding of energy allocation strategies underlying the superficial time allocation of wintering waterbirds according to environmental conditions.Exploring these changes can help understand the maximum fitness of wintering waterbirds in response to nature and human influences.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
Dietary threonine(Thr) deficiency increases hepatic triglyceride content and reduces sebum and abdominal fat percentages in lean type(LT), but not in fatty type(FT) Pekin ducks. However, the molecular changes regardin...Dietary threonine(Thr) deficiency increases hepatic triglyceride content and reduces sebum and abdominal fat percentages in lean type(LT), but not in fatty type(FT) Pekin ducks. However, the molecular changes regarding the role of Thr in lipid metabolism in LT and FT ducks induced by Thr deficiency remains unknown. This study compared differential expression gene profiles related to lipid metabolism in FT and LT Pekin ducks affected by Thr deficiency. We performed transcriptomic profiling and scanned the gene expression in the liver, sebum, and abdominal fat of Pekin ducks fed either Thr-deficient or Thr-adequate diet for 21 days from 14 to 35 days of age. There were 187, 52, and 50 differentially expressed genes(DEGs) identified in the liver, sebum, and abdominal fat of LT ducks affected by Thr deficiency, of which 12, 9, and 5 genes were involved in lipid metabolism, respectively. Thr deficiency altered the expression of 27, 6, and 3 genes in FT ducks’ liver, sebum, and abdominal fat, respectively. None of the DEGs had a relationship with lipid metabolism in FT ducks. KEGG analysis showed that the DEGs in the LT ducks’ livers were enriched in lipid metabolism pathways(linolenic acid metabolism, glycerophospholipid metabolism, and arachidonic acid metabolism) and amino acid metabolism pathways(biosynthesis of amino acids, phenylalanine metabolism, β-alanine metabolism, and glycine, serine and threonine metabolisms). The DEGs in the sebum and abdominal fat of LT ducks were not enriched in lipid and amino acid metabolic pathways. Additionally, DEGs involved in lipid metabolism were found to be upregulated by Thr deficiency in LT ducks, such as malic enzyme 3(ME3), acyl-Co A synthetase short-chain family member 2(ACSS2) in liver, and lipase member M(LIPM) in sebum. In summary, dietary Thr deficiency regulated the gene expression involved in lipid metabolism in the liver, sebum, and abdominal fat of Pekin ducks in a genotype-dependent manner.展开更多
The present study investigates the expression of microphthalmia-associated transcription factor(MITF) and its contribution to the melanin deposition in Liancheng white ducks.Nested PCR was used to clone the MITF gene ...The present study investigates the expression of microphthalmia-associated transcription factor(MITF) and its contribution to the melanin deposition in Liancheng white ducks.Nested PCR was used to clone the MITF gene sequence from the skin tissue of female Liancheng white ducks.Ultraviolet spectrophotometry was used to detect the melanin deposition.MITF mRNA expression and melanin deposition in different tissues and organs were detected and their correlation was analyzed.The MITF gene(GenBank number: MG516570) was 1 323 bp in length,contains a complete CDS region(34-1 323 bp) and codes 429 amino acids with 100% homology to the MITF of Anas platyrhynchos and over 95% homology to those of Gallus gallus and Coturnix japonica.Genetic evolution analysis reveals a close relationship of Liancheng white ducks with A.platyrhynchos,and also to lesser extents with Anser cygnoides,silky fowl and G.gallus,as well as Sus scrofa,Ovis aries and other mammals.Real-time quantitative PCR(qPCR) analysis demonstrated that MITF was expressed in skin,gizzard,liver,kidney and muscle,and of these tissues,its expression was the highest in the skin tissue(skin>gizzard>liver>kidney>muscle).Ultraviolet spectrophotometry showed that melanin deposition was positively correlated with the MITF expression level in these five tissues and organs(P<0.05).Together,these results demonstrated a tissue-specific pattern of MITF expression and a positive correlation between MITF expression and melanin deposition,indicating that MITF expression may contribute to the melanin deposition in Liancheng white ducks.展开更多
The effect of velogenic Newcastle disease virus (vNDV) on the immune responses and serum proteins was investigated in six-week-old ducks and chickens. Results showed that weight loss was markedly significant (p < 0...The effect of velogenic Newcastle disease virus (vNDV) on the immune responses and serum proteins was investigated in six-week-old ducks and chickens. Results showed that weight loss was markedly significant (p < 0.05) from days 3 - 21 (PI) in chickens and mild (p < 0.05) on days 3 and 15 PI in ducks. The antibody response obtained showed significant (p < 0.05) increase in infected chickens (IC) than those of the infected ducks (ID). While the total serum protein and serum globulin increased significantly (p < 0.05) in IC on days 7 and 14 PI, they decreased significantly (p < 0.05) in ID only on day 21 PI. The immune responses and serum protein values in this experiment X-ray showed less susceptibility of ducks when compared with the chickens. This may be related to marked anorexia and severe dehydration observed in the latter consequent upon serum concentration. Ducks could be maintaining the endemicity of Newcastle disease (ND) as reservoir host.展开更多
The hematological lesions consequent upon velogenic Newcastle disease virus (NDV) infection were investigated in 6-week-old ducks and chickens. Following intramuscular inoculation, the results indicated significantly ...The hematological lesions consequent upon velogenic Newcastle disease virus (NDV) infection were investigated in 6-week-old ducks and chickens. Following intramuscular inoculation, the results indicated significantly lower (p < 0.05) packed cell volume (PCV) in infected chickens (IC) on days 3 - 9 post inoculation (PI) and in infected ducks (ID) on days 3 - 15 PI. The hemoglobin concentrations were significantly lower (p < 0.05) in IC on days 3, 6 and 15 PI while in the ID, they were significantly lower (p < 0.05) on days 3, 9 and 15 PI. The total erythrocyte counts were significantly lower (p < 0.05) in IC on days 3, 9 and 15 PI and in ID, they were significantly lower (p < 0.05) on days 3 and 9 PI. The mean corpuscular values indicated macrocytic hypochromic anemia in IC and macrocytic normochromic anemia in ID. The leucogram showed leucopenia in IC and initial leucopenia followed by leucocytosis in ID. The hematological pictures of the velogenic NDV in this experiment indicate less susceptibility of ducks when compared with the chickens. The severity of this virus infection in chickens and the mild clinical signs and lesions presented by ducks showed that ducks are far less susceptible than chickens.展开更多
Cobb broilers and domestic ducks, both one-day-old, were treated using ration doped with 20 ppm of uranyl nitrate. Uranium concentrations in the tibia (μg-U/g-bone) were measured by neutron activation analysis as fun...Cobb broilers and domestic ducks, both one-day-old, were treated using ration doped with 20 ppm of uranyl nitrate. Uranium concentrations in the tibia (μg-U/g-bone) were measured by neutron activation analysis as function of the animals’ age, from the neonatal period to maturity. Results show that Uranium and Calcium qualitatively follow the same metabolic pathway, and that adult ducks incorporate on average ten times more Uranium than broilers. Data interpretation shows that the Uranium clearance rate in broilers is substantially higher than that in ducks, suggesting that metabolic characteristics favoring Calcium retention in bone may hinder the elimination of Uranium in ducks. The need for further comparative biochemistry studies between Galliformes and Anseriformes is addressed.展开更多
Duck hepatitis B virus(DHBV) shares many basic characteristics with hepatitis B virus(HBV) and is an attractive model for vaccine development. In this study, DHBV DNA vaccines were designed to express envelope and cap...Duck hepatitis B virus(DHBV) shares many basic characteristics with hepatitis B virus(HBV) and is an attractive model for vaccine development. In this study, DHBV DNA vaccines were designed to express envelope and capsid fusion proteins to enhance the breadth of immune response in ducks. Attenuated Salmonella typhimurium(SL7207) was used as a carrier and adjuvant to boost the magnitude of immune response. Based on this strategy, novel DNA vaccines(SL7207-p VAX1-LC and SL7207-p VAX1-SC) were generated. Growth kinetics, genetic stabilities and relative transcription levels of the L, S and C genes introduced by these vaccine strains were measured before inoculation to guarantee safety and efficacy. The relative transcript levels of the CD4 and CD8 T genes and the antibody levels(Ig Y) in ducks receiving the vaccines were higher than those in single gene delivered groups. Additionally, the copy number of covalently closed circular DNA in hepatocytes after DHBV challenge also provided evidence that our fusion vaccines could enhance the protective efficiency against DHBV infection in ducks.展开更多
Ducks inoculated intravenously or via the ocular-nasal-oral-cloacal routes with a highly pathogenic avian influenza virus,A/duck/Guangdong/220/2004(H5N1),developed systemic hyperemia,congestion,hemorrhage,thrombosis a...Ducks inoculated intravenously or via the ocular-nasal-oral-cloacal routes with a highly pathogenic avian influenza virus,A/duck/Guangdong/220/2004(H5N1),developed systemic hyperemia,congestion,hemorrhage,thrombosis and edema in various organs,as well as necrosis or apoptosis in the parenchyma of the heart,liver,spleen,lungs,kidneys,pancreas,brain,thymus and bursa of Fabricius.The main manifestations were angiitis,necrotic pancreatitis,atrophic necrotic thymitis and bursitis Fabricii,splenitis,tracheitis,hemorrhagic bronchointerstitial pneumonia,viral myocarditis,nonsuppurative encephalitis,focal viral hepatitis,ulcerative enteritis,renal tubule interstitial nephritis,and intraglomerular mesangial cell hyperplastic glomerular nephritis.The results demonstrated that the mechanism of pathogenesis involved cellular necrosis and apoptosis,and that death of the ducks was caused by severe pathologic trauma occurring in multiple visceral organs.展开更多
Salmonella Enteritidis(SE)is a zoonotic and vertically transmitted pathogen,often colonized in the reproductive tract of adult poultry,which can result in direct contamination of eggs and threaten human health.Previou...Salmonella Enteritidis(SE)is a zoonotic and vertically transmitted pathogen,often colonized in the reproductive tract of adult poultry,which can result in direct contamination of eggs and threaten human health.Previous studies have revealed that some pattern recognition receptors and resistance genes were involved in regulating immune responses to SE invasion in birds.However,the role of these immune response genes was not independent,and the interactions among the genes remained to be further investigated.In this study,SE burden and colonization were determined in reproductive tissue after the ducks were SE-infected,and RNA-sequencing was performed to construct co-expression networks by weighted gene co-expression network analysis(WGCNA).The result showed that SE could be isolated from 22% of infected-birds in any segment of the reproductive tract and the SE was readily colonized in the stroma,small follicle,isthmus,and vagina of the reproductive tracts in morbid ducks.The top central,highly connected genes were subsequently identified three specific modules in the above four tissues at the defined cut-offs(P<0.01),including 60 new candidate regulators and 125 transcription factors.Moreover,those 185 differentially expressed genes(DEGs)in these modules were co-expressed.Moreover,the hub genes(TRAF3,CXCR4 and IL13RA1)were identified to act with many other genes through immune response pathways including NF-kappaB,Toll-like receptor,steroid biosynthesis,and p53signaling pathways.These data provide references that will understand the immune regulatory relationships during SE infection,but also assist in the breeding of SE-resistant lines through potential biomarkers.展开更多
Although domestic ducks have been important poultry species throughout human history,their origin remains enigmatic,with mallards and/or Chinese spot-billed ducks being proposed as the direct wild ancestor(s)of domest...Although domestic ducks have been important poultry species throughout human history,their origin remains enigmatic,with mallards and/or Chinese spot-billed ducks being proposed as the direct wild ancestor(s)of domestic ducks.Here,we analyzed 118 whole genomes from mallard,Chinese spotbilled,and domestic ducks to reconstruct their evolutionary history.We found pervasive introgression patterns among these duck populations.Furthermore,we showed that domestic ducks separated from mallard and Chinese spotbilled ducks nearly 38 thousand years ago(kya)and 54 kya,respectively,which is considerably outside the time period of presumed duck domestication.Thus,our results suggest that domestic ducks may have originated from another wild duck population that is currently undefined or unsampled,rather than from present-day mallard and/or Chinese spot-billed ducks,as previously thought.Overall,this study provides new insight into the complex evolution of ducks.展开更多
Background:Although methionine(Met),the first-limiting dietary amino acid,has crucial roles in growth and regulation of lipid metabolism in ducks,mechanisms underlying are not well understood.Therefore,the objective w...Background:Although methionine(Met),the first-limiting dietary amino acid,has crucial roles in growth and regulation of lipid metabolism in ducks,mechanisms underlying are not well understood.Therefore,the objective was to use dietary Met deficiency to investigate the involvement of Met in lipid metabolism and fat accumulation of Pekin ducks.Methods:A total of 150 male Pekin ducks(15-d-old,558.5±4.4 g)were allocated into 5 groups(6 replicates with 5 birds each)and fed corn and soybean meal-based diets containing 0.28%,0.35%,0.43%,0.50%,and 0.58%Met,respectively,for 4 weeks.Met-deficient(Met-D,0.28%Met)and Met-adequate(Met-A,0.43%Met)groups were selected for subsequent molecular studies.Serum,liver,and abdominal fat samples were collected to assess the genes and proteins involved in lipid metabolism of Pekin ducks and hepatocytes were cultured in vivo for verification.Results:Dietary Met deficiency caused growth depression and excess fat deposition that were ameliorated by feeding diets with adequate Met.Serum triglyceride and non-esterified fatty acid concentrations increased(P<0.05),whereas serum concentrations of total cholesterol,low density lipoprotein cholesterol,total protein,and albumin decreased(P<0.05)in Met-D ducks compared to those in Met-A ducks.Based on hepatic proteomics analyses,dietary Met deficiency suppressed expression of key proteins related to fatty acid transport,fatty acid oxidation,tricarboxylic acid cycle,glycolysis/gluconeogenesis,ketogenesis,and electron transport chain;selected key proteins had similar expression patterns verified by qRT-PCR and Western blotting,which indicated these processes were likely impaired.In vitro verification with hepatocyte models confirmed albumin expression was diminished by Met deficiency.Additionally,in abdominal fat,dietary Met deficiency increased adipocyte diameter and area(P<0.05),and down-regulated(P<0.05)of lipolytic genes and proteins,suggesting Met deficiency may suppress lipolysis in adipocyte.Conclusion:Taken together,these data demonstrated that dietary Met deficiency in Pekin ducks resulted in stunted growth and excess fat deposition,which may be related to suppression of fatty acids transportation and hepatic catabolism.展开更多
Neuropeptide S(NPS)is involved in severe pathological processes.Direct evidence showed NPS regulates the secretion of proinflammatory cytokines in pigs.This study investigated the effect of NPS on the secretion of inf...Neuropeptide S(NPS)is involved in severe pathological processes.Direct evidence showed NPS regulates the secretion of proinflammatory cytokines in pigs.This study investigated the effect of NPS on the secretion of inflammatory cytokines in ducks with H9N2 infection via intramuscular injection with NPS or NPS receptor(NPSR)antagonist.The ducks received 15 nM NPS or 10 nM NPSR antagonist in saline.Samples were collected to analyze the expression levels of IL-1β,IL-6,TNF-α,IFN-α,NPS,and the H9N2 gene NP by RT-PCR and real time RT-PCR;samples were fixed to observe the histopathological changes by hematoxylin-eosin staining.Serial blood samples were collected(every 30 min,starting 1 h before injections and lasting until 2 h after injections)to measure the serum levels of IL-1β,IL-6,TNF-α,and IFN-αby ELISA.Semiquantitative RT-PCR confirmed that the expression of NPS mRNA was increased in H9N2 infection group.Morphological data showed NPS treatment could reverse the pathological changes in the duck bursa induced by H9N2 infection.Both the results of real time quantitative RT-PCR and ELISA methods showed NPS and NPSR antagonist treatments could significantly regulate the expression of IFN-α,but not of IL-1β,IL-6 and TNF-α;meanwhile,the levels of increased IFN-α and decreased NP were further prompted by NPS,and NPSR antagonist revered.Conclusion,NPS is involved in the innate immunity response to H9N2 infection via the IFN-αpathway in ducks in vivo.These results indicate NPS affects the immune homeostasis and provides an alternative for anti-H9N2 drugs.展开更多
From a total of 80 fertile eggs incubated naturally by female ducks, healthy sexed ducklings (n = 64, 32 males and 32 females ducklings) were randomly selected and allotted to four dietary treatments with four replica...From a total of 80 fertile eggs incubated naturally by female ducks, healthy sexed ducklings (n = 64, 32 males and 32 females ducklings) were randomly selected and allotted to four dietary treatments with four replicates, in a completely randomized design in order to evaluate the effect of varying levels of palm kernel meal (PKM) on performance of ducklings. The dietary treatments comprised R0-control ration, R50-50% PKM replacement, R75-75% PKM re-placement and R100-100% PKM replacement of soyabean meal. The main results revealed that the apparent digestive coefficients of dry matter (81.12%), organic matter (83.98%) and NDF (81.10%) were higher with the ration in which 50% (R50-50% PKM replacement of soyabean meal) of soybean was replaced by palm kernel meal. The highest feed intake in male was recorded with the ration containing 75% (R75-75% PKM replacement of soyabean meal) of palm kernel. This same ration (R75-75% PKM replacement of soyabean meal) equally induced the highest live weight and weight gain in females. The experimental design and arrangement is a 2 × 4 factorial arrangement with two sexes and four levels of PKM. In males, the control ration without palm kernel meal induced the highest live weight and highest cumulative weight gain. The lowest feed conversion ratio (p < 0.05) was recorded with the control ration regardless of the sex considered. The lowest cost of feed in-take and cost of production of a kg of body weight were obtained respectively in females and males fed on control ration. With the 50% (R50-50% PKM re-placement of soyabean meal) substitution of soybean meal, the carcass yield was the highest regardless of the sex. Serum content in ALAT, ASAT, creatinine, total cholesterol and total protein were not significantly (p > 0.05) affected by the incorporation of palm kernel meal into the diet. Urea serum content tends to decrease with the increasing level of palm kernel meal in feed. In conclusion, soybean meal can advantageously be replaced by palm kernel meal at the level of 75% (R75-75% PKM replacement of soyabean meal) in Muscovy duck feed.展开更多
基金supported by the Natural Science Foundation of Sichuan Province(No.2022NSFSC0060)。
文摘Background Zinc glycine chelate(Zn-Gly)has anti-inflammation and growth-promoting properties;however,the mechanism of Zn-Gly contribution to gut barrier function in Cherry Valley ducks during intestinal inflammation is unknown.Three-hundred 1-day-old ducks were divided into 5 groups(6 replicates and 10 ducks per replicate)in a completely randomized design:the control and dextran sulfate sodium(DSS)groups were fed a corn-soybean meal basal diet,and experimental groups received supplements of 70,120 or 170 mg/kg Zn in form of Zn-Gly.The DSS and treatment groups were given 2 mL of 0.45 g/mL DSS daily during d 15–21,and the control group received normal saline.The experiment lasted 21 d.Results Compared with DSS group,70,120 and 170 mg/kg Zn significantly increased body weight(BW),villus height and the ratio of villus to crypt,and significantly decreased the crypt depth of jejunum at 21 d.The number of goblet cells in jejunal villi in the Zn-Gly group was significantly increased by periodic acid-Schiff staining.Compared with control,the content of intestinal permeability marker D-lactic acid(D-LA)and fluxes of fluorescein isothiocyanate(FITC-D)in plasma of DSS group significantly increased,and 170 mg/kg Zn supplementation significantly decreased the D-LA content and FITC-D fluxes.Compared with control,contents of plasma,jejunum endotoxin and jejunum pro-inflammatory factors IL-1β,IL-6 and TNF-αwere significantly increased in DSS group,and were significantly decreased by 170 mg/kg Zn supplementation.Dietary Zn significantly increased the contents of anti-inflammatory factors IL-10,IL-22 and sIgA and IgG in jejunum.Real-time PCR and Western blot results showed that 170 mg/kg Zn supplementation significantly increased mRNA expression levels of CLDN-1 and expression of OCLN protein in jejunum,and decreased gene and protein expression of CLDN-2 compared with DSS group.The 120 mg/kg Zn significantly promoted the expressions of IL-22 and IgA.Dietary Zn-Gly supplementation significantly decreased pro-inflammatory genes IL-8 and TNF-αexpression levels and TNF-αprotein expression in jejunum.Additionally,Zn significantly reduced the gene and protein expression of TLR4,MYD88 and NF-κB p65.Conclusions Zn-Gly improved duck BW and alleviated intestinal injury by regulating intestinal morphology,barrier function and gut inflammation-related signal pathways TLR4/MYD88/NF-κB p65.
基金supported by the National Natural Science Foundation of China (Grant No. 32100400)Huangshan University Startup Project of Scientific Research (2020xkjq013)Environment Conservation Research Centre of Xin’an River Basin (kypt202002)。
文摘Rivers are important habitats for wintering waterbirds.However,they are easily influenced by natural and human activities.An important approach for waterbirds to adapt to habitats is adjusting the activity time and energy expenditure allocation of diurnal behavior.The compensatory foraging hypothesis predicts that increased energy expenditure leads to longer foraging time,which in turn increases food intake and helps maintain a constant energy balance.However,it is unclear whether human-disturbed habitats result in increased energy expenditure related to safety or foraging.In this study,the scan sample method was used to observe the diurnal behavior of the wintering Spot-billed Duck(Anas poecilorhyncha) in two rivers in the Xin’an River Basin from October 2021 to March 2022.The allocation of time and energy expenditure for activity in both normal and disturbed environments was calculated.The results showed that foraging accounted for the highest percentage of time and energy expenditure.Additionally,foraging decreased in the disturbed environment than that in the normal environment.Resting behavior showed the opposite trend,while other behaviors were similar in both environments.The total diurnal energy expenditure of ducks in the disturbed environment was greater than that in the normal environment,with decreased foraging and resting time percentage and increased behaviors related to immediate safety(swimming and alert) and comfort.These results oppose the compensatory foraging hypothesis in favor of increased security.The optimal diurnal energy expenditure model included river width and water depth,which had a positive relationship;an increase in either of these two factors resulted in an increase in energy expenditure.This study provides a better understanding of energy allocation strategies underlying the superficial time allocation of wintering waterbirds according to environmental conditions.Exploring these changes can help understand the maximum fitness of wintering waterbirds in response to nature and human influences.
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.
基金supported by the National Natural Science Foundation of China(31902174)the Natural Science Foundation of Jiangsu Province,China(BK20190902)the Natural Science Foundation of Jiangsu Higher Education Institutions of China(19KJD230003)。
文摘Dietary threonine(Thr) deficiency increases hepatic triglyceride content and reduces sebum and abdominal fat percentages in lean type(LT), but not in fatty type(FT) Pekin ducks. However, the molecular changes regarding the role of Thr in lipid metabolism in LT and FT ducks induced by Thr deficiency remains unknown. This study compared differential expression gene profiles related to lipid metabolism in FT and LT Pekin ducks affected by Thr deficiency. We performed transcriptomic profiling and scanned the gene expression in the liver, sebum, and abdominal fat of Pekin ducks fed either Thr-deficient or Thr-adequate diet for 21 days from 14 to 35 days of age. There were 187, 52, and 50 differentially expressed genes(DEGs) identified in the liver, sebum, and abdominal fat of LT ducks affected by Thr deficiency, of which 12, 9, and 5 genes were involved in lipid metabolism, respectively. Thr deficiency altered the expression of 27, 6, and 3 genes in FT ducks’ liver, sebum, and abdominal fat, respectively. None of the DEGs had a relationship with lipid metabolism in FT ducks. KEGG analysis showed that the DEGs in the LT ducks’ livers were enriched in lipid metabolism pathways(linolenic acid metabolism, glycerophospholipid metabolism, and arachidonic acid metabolism) and amino acid metabolism pathways(biosynthesis of amino acids, phenylalanine metabolism, β-alanine metabolism, and glycine, serine and threonine metabolisms). The DEGs in the sebum and abdominal fat of LT ducks were not enriched in lipid and amino acid metabolic pathways. Additionally, DEGs involved in lipid metabolism were found to be upregulated by Thr deficiency in LT ducks, such as malic enzyme 3(ME3), acyl-Co A synthetase short-chain family member 2(ACSS2) in liver, and lipase member M(LIPM) in sebum. In summary, dietary Thr deficiency regulated the gene expression involved in lipid metabolism in the liver, sebum, and abdominal fat of Pekin ducks in a genotype-dependent manner.
基金supported by the National Natural Science Foundation of China (31372474)the National Guidance Project for Local Science and Technology Development,China (2018L3004)+3 种基金the National and FNU Training Program of Innovation and Enterpreneurship for Undergraduates, China (201910394023, CXXL2019268 and CXXL2019274)the Fujian Province Public Welfare Scientific Project, China (018R1023-2)the Fujian Development and Reform Commission “Five News” Project of China (fjfgw201806)the Young Talent Innovation Funding of Fujian Academy of Agricultural Sciences of China (YC2017-7 and MYQJ2015-5)
文摘The present study investigates the expression of microphthalmia-associated transcription factor(MITF) and its contribution to the melanin deposition in Liancheng white ducks.Nested PCR was used to clone the MITF gene sequence from the skin tissue of female Liancheng white ducks.Ultraviolet spectrophotometry was used to detect the melanin deposition.MITF mRNA expression and melanin deposition in different tissues and organs were detected and their correlation was analyzed.The MITF gene(GenBank number: MG516570) was 1 323 bp in length,contains a complete CDS region(34-1 323 bp) and codes 429 amino acids with 100% homology to the MITF of Anas platyrhynchos and over 95% homology to those of Gallus gallus and Coturnix japonica.Genetic evolution analysis reveals a close relationship of Liancheng white ducks with A.platyrhynchos,and also to lesser extents with Anser cygnoides,silky fowl and G.gallus,as well as Sus scrofa,Ovis aries and other mammals.Real-time quantitative PCR(qPCR) analysis demonstrated that MITF was expressed in skin,gizzard,liver,kidney and muscle,and of these tissues,its expression was the highest in the skin tissue(skin>gizzard>liver>kidney>muscle).Ultraviolet spectrophotometry showed that melanin deposition was positively correlated with the MITF expression level in these five tissues and organs(P<0.05).Together,these results demonstrated a tissue-specific pattern of MITF expression and a positive correlation between MITF expression and melanin deposition,indicating that MITF expression may contribute to the melanin deposition in Liancheng white ducks.
文摘The effect of velogenic Newcastle disease virus (vNDV) on the immune responses and serum proteins was investigated in six-week-old ducks and chickens. Results showed that weight loss was markedly significant (p < 0.05) from days 3 - 21 (PI) in chickens and mild (p < 0.05) on days 3 and 15 PI in ducks. The antibody response obtained showed significant (p < 0.05) increase in infected chickens (IC) than those of the infected ducks (ID). While the total serum protein and serum globulin increased significantly (p < 0.05) in IC on days 7 and 14 PI, they decreased significantly (p < 0.05) in ID only on day 21 PI. The immune responses and serum protein values in this experiment X-ray showed less susceptibility of ducks when compared with the chickens. This may be related to marked anorexia and severe dehydration observed in the latter consequent upon serum concentration. Ducks could be maintaining the endemicity of Newcastle disease (ND) as reservoir host.
文摘The hematological lesions consequent upon velogenic Newcastle disease virus (NDV) infection were investigated in 6-week-old ducks and chickens. Following intramuscular inoculation, the results indicated significantly lower (p < 0.05) packed cell volume (PCV) in infected chickens (IC) on days 3 - 9 post inoculation (PI) and in infected ducks (ID) on days 3 - 15 PI. The hemoglobin concentrations were significantly lower (p < 0.05) in IC on days 3, 6 and 15 PI while in the ID, they were significantly lower (p < 0.05) on days 3, 9 and 15 PI. The total erythrocyte counts were significantly lower (p < 0.05) in IC on days 3, 9 and 15 PI and in ID, they were significantly lower (p < 0.05) on days 3 and 9 PI. The mean corpuscular values indicated macrocytic hypochromic anemia in IC and macrocytic normochromic anemia in ID. The leucogram showed leucopenia in IC and initial leucopenia followed by leucocytosis in ID. The hematological pictures of the velogenic NDV in this experiment indicate less susceptibility of ducks when compared with the chickens. The severity of this virus infection in chickens and the mild clinical signs and lesions presented by ducks showed that ducks are far less susceptible than chickens.
文摘Cobb broilers and domestic ducks, both one-day-old, were treated using ration doped with 20 ppm of uranyl nitrate. Uranium concentrations in the tibia (μg-U/g-bone) were measured by neutron activation analysis as function of the animals’ age, from the neonatal period to maturity. Results show that Uranium and Calcium qualitatively follow the same metabolic pathway, and that adult ducks incorporate on average ten times more Uranium than broilers. Data interpretation shows that the Uranium clearance rate in broilers is substantially higher than that in ducks, suggesting that metabolic characteristics favoring Calcium retention in bone may hinder the elimination of Uranium in ducks. The need for further comparative biochemistry studies between Galliformes and Anseriformes is addressed.
基金supported by the National Key Technology R&D Program of China(2015BAD12B05)the earmarked fund for China Agricultural Research System(CARS-43-8)+1 种基金the Integration and Demonstration of Key Technologies for Duck Industry in Sichuan Province,China(2014NZ0030)the Sichuan Province Research Programs,China(2014-002)
文摘Duck hepatitis B virus(DHBV) shares many basic characteristics with hepatitis B virus(HBV) and is an attractive model for vaccine development. In this study, DHBV DNA vaccines were designed to express envelope and capsid fusion proteins to enhance the breadth of immune response in ducks. Attenuated Salmonella typhimurium(SL7207) was used as a carrier and adjuvant to boost the magnitude of immune response. Based on this strategy, novel DNA vaccines(SL7207-p VAX1-LC and SL7207-p VAX1-SC) were generated. Growth kinetics, genetic stabilities and relative transcription levels of the L, S and C genes introduced by these vaccine strains were measured before inoculation to guarantee safety and efficacy. The relative transcript levels of the CD4 and CD8 T genes and the antibody levels(Ig Y) in ducks receiving the vaccines were higher than those in single gene delivered groups. Additionally, the copy number of covalently closed circular DNA in hepatocytes after DHBV challenge also provided evidence that our fusion vaccines could enhance the protective efficiency against DHBV infection in ducks.
基金supported by the Guangdong Province Science&Technology Hard Nut Project(2004A2090102)Guangdong Province Education Bureau Science Foundation Project(Z02003)
文摘Ducks inoculated intravenously or via the ocular-nasal-oral-cloacal routes with a highly pathogenic avian influenza virus,A/duck/Guangdong/220/2004(H5N1),developed systemic hyperemia,congestion,hemorrhage,thrombosis and edema in various organs,as well as necrosis or apoptosis in the parenchyma of the heart,liver,spleen,lungs,kidneys,pancreas,brain,thymus and bursa of Fabricius.The main manifestations were angiitis,necrotic pancreatitis,atrophic necrotic thymitis and bursitis Fabricii,splenitis,tracheitis,hemorrhagic bronchointerstitial pneumonia,viral myocarditis,nonsuppurative encephalitis,focal viral hepatitis,ulcerative enteritis,renal tubule interstitial nephritis,and intraglomerular mesangial cell hyperplastic glomerular nephritis.The results demonstrated that the mechanism of pathogenesis involved cellular necrosis and apoptosis,and that death of the ducks was caused by severe pathologic trauma occurring in multiple visceral organs.
基金supported by the National Natural Science Foundation of China(31702107)the Open Project Program of Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China,Yangzhou University,China(JILARKF202018)。
文摘Salmonella Enteritidis(SE)is a zoonotic and vertically transmitted pathogen,often colonized in the reproductive tract of adult poultry,which can result in direct contamination of eggs and threaten human health.Previous studies have revealed that some pattern recognition receptors and resistance genes were involved in regulating immune responses to SE invasion in birds.However,the role of these immune response genes was not independent,and the interactions among the genes remained to be further investigated.In this study,SE burden and colonization were determined in reproductive tissue after the ducks were SE-infected,and RNA-sequencing was performed to construct co-expression networks by weighted gene co-expression network analysis(WGCNA).The result showed that SE could be isolated from 22% of infected-birds in any segment of the reproductive tract and the SE was readily colonized in the stroma,small follicle,isthmus,and vagina of the reproductive tracts in morbid ducks.The top central,highly connected genes were subsequently identified three specific modules in the above four tissues at the defined cut-offs(P<0.01),including 60 new candidate regulators and 125 transcription factors.Moreover,those 185 differentially expressed genes(DEGs)in these modules were co-expressed.Moreover,the hub genes(TRAF3,CXCR4 and IL13RA1)were identified to act with many other genes through immune response pathways including NF-kappaB,Toll-like receptor,steroid biosynthesis,and p53signaling pathways.These data provide references that will understand the immune regulatory relationships during SE infection,but also assist in the breeding of SE-resistant lines through potential biomarkers.
基金This study was supported by the Natural Science Foundation of Anhui Province(1908085QC143)the Natural Science Foundation for Young Scholars of Anhui Agricultural University(yj2018-51)。
文摘Although domestic ducks have been important poultry species throughout human history,their origin remains enigmatic,with mallards and/or Chinese spot-billed ducks being proposed as the direct wild ancestor(s)of domestic ducks.Here,we analyzed 118 whole genomes from mallard,Chinese spotbilled,and domestic ducks to reconstruct their evolutionary history.We found pervasive introgression patterns among these duck populations.Furthermore,we showed that domestic ducks separated from mallard and Chinese spotbilled ducks nearly 38 thousand years ago(kya)and 54 kya,respectively,which is considerably outside the time period of presumed duck domestication.Thus,our results suggest that domestic ducks may have originated from another wild duck population that is currently undefined or unsampled,rather than from present-day mallard and/or Chinese spot-billed ducks,as previously thought.Overall,this study provides new insight into the complex evolution of ducks.
基金supported by China Agriculture Research System of MOF and MARA(CARS-42)the Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences(CXGC-IAS-09)Central Scientific Institution Fundamental Research Funds(1610382022005).
文摘Background:Although methionine(Met),the first-limiting dietary amino acid,has crucial roles in growth and regulation of lipid metabolism in ducks,mechanisms underlying are not well understood.Therefore,the objective was to use dietary Met deficiency to investigate the involvement of Met in lipid metabolism and fat accumulation of Pekin ducks.Methods:A total of 150 male Pekin ducks(15-d-old,558.5±4.4 g)were allocated into 5 groups(6 replicates with 5 birds each)and fed corn and soybean meal-based diets containing 0.28%,0.35%,0.43%,0.50%,and 0.58%Met,respectively,for 4 weeks.Met-deficient(Met-D,0.28%Met)and Met-adequate(Met-A,0.43%Met)groups were selected for subsequent molecular studies.Serum,liver,and abdominal fat samples were collected to assess the genes and proteins involved in lipid metabolism of Pekin ducks and hepatocytes were cultured in vivo for verification.Results:Dietary Met deficiency caused growth depression and excess fat deposition that were ameliorated by feeding diets with adequate Met.Serum triglyceride and non-esterified fatty acid concentrations increased(P<0.05),whereas serum concentrations of total cholesterol,low density lipoprotein cholesterol,total protein,and albumin decreased(P<0.05)in Met-D ducks compared to those in Met-A ducks.Based on hepatic proteomics analyses,dietary Met deficiency suppressed expression of key proteins related to fatty acid transport,fatty acid oxidation,tricarboxylic acid cycle,glycolysis/gluconeogenesis,ketogenesis,and electron transport chain;selected key proteins had similar expression patterns verified by qRT-PCR and Western blotting,which indicated these processes were likely impaired.In vitro verification with hepatocyte models confirmed albumin expression was diminished by Met deficiency.Additionally,in abdominal fat,dietary Met deficiency increased adipocyte diameter and area(P<0.05),and down-regulated(P<0.05)of lipolytic genes and proteins,suggesting Met deficiency may suppress lipolysis in adipocyte.Conclusion:Taken together,these data demonstrated that dietary Met deficiency in Pekin ducks resulted in stunted growth and excess fat deposition,which may be related to suppression of fatty acids transportation and hepatic catabolism.
基金Supported by National Nature Science Foundation of China(31302050)Fujian Provincial Key Lab-oratory of Livestock Infectious Disease for Prevention and Biotechnology at Longyan University(2018KF03)Fujian Agriculture and Forestry University Teaching Reform Project(111418106)&Fujian Agriculture and Forestry University College Students’ Innovation Project(201910389198)
文摘Neuropeptide S(NPS)is involved in severe pathological processes.Direct evidence showed NPS regulates the secretion of proinflammatory cytokines in pigs.This study investigated the effect of NPS on the secretion of inflammatory cytokines in ducks with H9N2 infection via intramuscular injection with NPS or NPS receptor(NPSR)antagonist.The ducks received 15 nM NPS or 10 nM NPSR antagonist in saline.Samples were collected to analyze the expression levels of IL-1β,IL-6,TNF-α,IFN-α,NPS,and the H9N2 gene NP by RT-PCR and real time RT-PCR;samples were fixed to observe the histopathological changes by hematoxylin-eosin staining.Serial blood samples were collected(every 30 min,starting 1 h before injections and lasting until 2 h after injections)to measure the serum levels of IL-1β,IL-6,TNF-α,and IFN-αby ELISA.Semiquantitative RT-PCR confirmed that the expression of NPS mRNA was increased in H9N2 infection group.Morphological data showed NPS treatment could reverse the pathological changes in the duck bursa induced by H9N2 infection.Both the results of real time quantitative RT-PCR and ELISA methods showed NPS and NPSR antagonist treatments could significantly regulate the expression of IFN-α,but not of IL-1β,IL-6 and TNF-α;meanwhile,the levels of increased IFN-α and decreased NP were further prompted by NPS,and NPSR antagonist revered.Conclusion,NPS is involved in the innate immunity response to H9N2 infection via the IFN-αpathway in ducks in vivo.These results indicate NPS affects the immune homeostasis and provides an alternative for anti-H9N2 drugs.
文摘From a total of 80 fertile eggs incubated naturally by female ducks, healthy sexed ducklings (n = 64, 32 males and 32 females ducklings) were randomly selected and allotted to four dietary treatments with four replicates, in a completely randomized design in order to evaluate the effect of varying levels of palm kernel meal (PKM) on performance of ducklings. The dietary treatments comprised R0-control ration, R50-50% PKM replacement, R75-75% PKM re-placement and R100-100% PKM replacement of soyabean meal. The main results revealed that the apparent digestive coefficients of dry matter (81.12%), organic matter (83.98%) and NDF (81.10%) were higher with the ration in which 50% (R50-50% PKM replacement of soyabean meal) of soybean was replaced by palm kernel meal. The highest feed intake in male was recorded with the ration containing 75% (R75-75% PKM replacement of soyabean meal) of palm kernel. This same ration (R75-75% PKM replacement of soyabean meal) equally induced the highest live weight and weight gain in females. The experimental design and arrangement is a 2 × 4 factorial arrangement with two sexes and four levels of PKM. In males, the control ration without palm kernel meal induced the highest live weight and highest cumulative weight gain. The lowest feed conversion ratio (p < 0.05) was recorded with the control ration regardless of the sex considered. The lowest cost of feed in-take and cost of production of a kg of body weight were obtained respectively in females and males fed on control ration. With the 50% (R50-50% PKM re-placement of soyabean meal) substitution of soybean meal, the carcass yield was the highest regardless of the sex. Serum content in ALAT, ASAT, creatinine, total cholesterol and total protein were not significantly (p > 0.05) affected by the incorporation of palm kernel meal into the diet. Urea serum content tends to decrease with the increasing level of palm kernel meal in feed. In conclusion, soybean meal can advantageously be replaced by palm kernel meal at the level of 75% (R75-75% PKM replacement of soyabean meal) in Muscovy duck feed.
