Background Selective breeding for disease resistance is an effective strategy to control duck hepatitis A virus type 3(DHAV-3)in waterfowl.However,the mechanism underlying resistance remains poorly understood,particul...Background Selective breeding for disease resistance is an effective strategy to control duck hepatitis A virus type 3(DHAV-3)in waterfowl.However,the mechanism underlying resistance remains poorly understood,particularly those associated with antioxidant defense,intestinal development and host-microbiota interactions.Method A total of 1001-day-old Pekin ducklings were used in this study with 50 DHAV-3 susceptible and resistant ducks,respectively.Samples were collected at 7 days post-hatching(D7),D21 and D42,10 birds per group.We compared DHAV-3 resistant and susceptible ducks during early development with respect to immune organ indices,antioxidant capacity,intestinal morphology,barrier-related gene expression and cecal microbiota.Result Resistant ducks exhibited higher spleen indices and stronger antioxidant capacity,characterized by increased superoxide dismutase,reduced glutathione,and total antioxidant capacity,along with lower malondialdehyde levels at D7 and D21.In contrast,susceptible ducks showed compensatory thymus hypertrophy and delayed development of antioxidant defense and intestinal maturation.Ileal morphology revealed greater villus height and width with more regular arrangement in resistant ducks at D7,whereas these differences diminished at D21 and D42.Gene expression analysis demonstrated higher early expression of the tight junction proteins CLDN1 and CLDN3 in resistant ducks,while susceptible ducks displayed elevated MUC2 and OCLN,suggesting stress induced compensatory responses.Cecal microbiota analysis revealed distinct colonization patterns in early development.Resistant ducks were enriched with Firmicutes and beneficial genera such as Enterococcus and Lactobacillus,whereas susceptible ducks harbored higher abundances of Bacteroidota and potentially opportunistic taxa.Microbial diversity increased with age in both groups,but resistant ducks displayed more orderly succession and enrichment of SCFA producing genera,including Subdoligranulum and Phascolarctobacterium,which positively correlated with plasma antioxidant indices.Conclusion DHAV-3 resistant ducks exhibit early advantages in antioxidant defense,intestinal barrier development and colonization by beneficial microbiota,which collectively contribute to enhanced disease resistance.These findings highlight the synergistic roles of host physiology and gut microbiota in shaping resistance.In the future,integrating genomic selection with microbiota modulation and antioxidant interventions may accelerate the breeding of highly resistant duck lines and provide scientific evidence and practical strategies for controlling duck viral hepatitis.展开更多
The demand for duck meat, duck eggs, and associated products is increasing each year. Classic and modern selection programs have been applied to enhance the economic traits of ducks to satisfy the requirements of cons...The demand for duck meat, duck eggs, and associated products is increasing each year. Classic and modern selection programs have been applied to enhance the economic traits of ducks to satisfy the requirements of consumers and enhance the incomes of producers. The nutritional requirements of unselected ducks may not be adequate, however, to fulfill the potential productivity performance of modern birds, including both meat-type and egg-type ducks. In particular, an imbalanced diet is associated with low productive performance and signs of nutritional deficiency（if insufficient nutrients are supplied）, as well as with high feed costs and manure problems that reflect flock health and welfare（if excessive nutrients are supplied）. Thus, the main aim of this review is to summarize the results of previous studies that estimated the nutrient requirements of meat-type and egg-type ducks in order to evaluate current knowledge and to identify further issues that need to be addressed. In addition,the results obtained in previous studies are compared in order to understand how to lower commercial feed costs,fulfill the genetic potential of selected ducks, protect the environment from pollution, and satisfy the welfare and health needs of ducks.展开更多
Background AflatoxinB1(AFB_(1))is a prevalent contaminant in agricultural products,presenting significant risks to animal health.CotA laccase from Bacillus licheniformis has shown significant efficacy in degrading myc...Background AflatoxinB1(AFB_(1))is a prevalent contaminant in agricultural products,presenting significant risks to animal health.CotA laccase from Bacillus licheniformis has shown significant efficacy in degrading mycotoxins in vitro test.The efficacy of Bacillus CotA laccase in animals,however,remains to be confirmed.A 2×2 factorial design was used to investigate the effects of Bacillus CotA laccase level(0 or 1 U/kg),AFB_(1) challenge(challenged or unchal-lenged)and their interactions on ducks.The purpose of this study was to evaluate the efficacy of Bacillus CotA laccase in alleviatingAFB_(1) toxicosis of ducks.Results Bacillus CotA laccase alleviatedAFB_(1)-induced declines in growth performance of ducks accompanied by improved average daily gain(ADG)and lower feed/gain ratio(F/G).Bacillus CotA laccase amelioratedAFB_(1)-induced gut barrier dysfunctions and inflammation testified by increasing the jejunal villi height/crypt depth ratio(VH/CD)and the mRNA expression of tight junction protein 1(TJP1)and zonula occluden-1(ZO-1)as well as decreasing the expression of inflammation-related genes in the jejunum of ducks.Amino acid metabolome showed that Bacillus CotA laccase amelioratedAFB_(1)-induced amino acid metabolism disorders evidenced by increasing the level of glu-tamic acid in serum and upregulating the expression of amino acid transport related genes in jejunum of ducks.Bacil-lus CotA laccase amelioratedAFB_(1)-induced liver injury testified by suppressing oxidative stress,inhibiting apoptosis,and downregulating the expression of hepatic metabolic enzyme related genes of ducks.Moreover,Bacillus CotA laccase degradedAFB_(1) in digestive tract of ducks,resulting in the reduced absorption level ofAFB_(1) across intestinal epithelium testified by the decreased level ofAFB_(1)-DNA adduct in the liver,and the reduced content ofAFB_(1) residues in liver and feces of ducks.Conclusions Bacillus CotA laccase effectively improved the growth performance,intestinal health,amino acid metabolism and hepatic aflatoxin metabolism of ducks fedAFB_(1) diets,highlighting its potential as an efficient and safe feed enzyme forAFB_(1) degradation in animal production.展开更多
In order to investigate the effects of probiotics on growth performance, blood biochemical indexes and economic benefits of Cherry Valley ducks, different probiotics were added into the feed of Cherry Valley ducks. To...In order to investigate the effects of probiotics on growth performance, blood biochemical indexes and economic benefits of Cherry Valley ducks, different probiotics were added into the feed of Cherry Valley ducks. Total 240 1-d-old Cherry Valley ducks were selected, and they were randomly divided into 4 groups, including 1 control group and 3 treatment groups. There were 3 replicates for each group and there were 20 ducks for each replicate. The ducks in the control group were fed the basal diet, and the ducks in the 3 treatment groups were fed the basal diet added with Lactobacillus, Bacillus natto and florfenicol, respectively. The test lasted for 42 d. The results showed that the addition of Lactobacillus and Bacillus natto could improve the average daily weight gain and final average weight （P〈0.05） of Cherry Valley ducks, and reduce the glutamic-pyruvic transaminase ac- tivity, alkaline phosphatase activity and serum urinary nitrogen content in duck blood （P〈0.05） and reduce the creatinine content and total cholesterol content in Cherry Valley ducks （P〉0.05）; at the same time, adding probiotics to feed could also in- crease the grass economic benefits of Cherry Valley ducks. In overall, the effects of adding probiotics were better than those of adding antibiotic.展开更多
Agro-ecological conditions associated with the spread and persistence of highly pathogenic avian inlfuenza （HPAI） are not well understood, but the trade of live poultry is suspected to be a major pathway. Although m...Agro-ecological conditions associated with the spread and persistence of highly pathogenic avian inlfuenza （HPAI） are not well understood, but the trade of live poultry is suspected to be a major pathway. Although market chains of live bird trade have been studied through indirect means including interviews and questionnaires, direct methods have not been used to identify movements of individual poultry. To bridge the knowledge gap on quantitative movement and transportation of poultry, we introduced a novel approach for applying telemetry to document domestic duck movements from source farms at Poyang Lake, China. We deployed recently developed transmitters that record Global Positioning System （GPS） locations and send them through the Groupe Spécial Mobile （GSM） cellular telephone system. For the ifrst time, we were able to track individually marked ducks from 3 to 396 km from their origin to other farms, distribution facilities, or live bird markets. Our proof of concept test showed that the use of GPS-GSM transmitters may provide di-rect, quantitative information to document the movement of poultry and reveal their market chains. Our ifndings provide an initial indication of the complexity of source-market network connectivity and highlight the great potential for future telemetry studies in poultry network analyses.展开更多
MicroRNAs （miRNAs）, which post-transcriptionally regulate gene expression by binding to the 3′untranslated region of mRNAs to either inhibit or enhance translation, are involved in diverse biological processes. The...MicroRNAs （miRNAs）, which post-transcriptionally regulate gene expression by binding to the 3′untranslated region of mRNAs to either inhibit or enhance translation, are involved in diverse biological processes. The use of high-throughput Solexa sequencing plays important roles in the discovery of miRNAs. In this study, we used high-throughput Solexa sequencing to identify novel duck miRNAs and compare the miRNA expression profiles in laying and non-laying duck ovaries. Using a bioinformatic analysis, we discovered 86 potential duck miRNAs similar to known chicken miRNAs and 43 unique sequences that matched known miRNAs of other species. We also found that miRNA variations and isoforms were widespread in our two RNA libraries, with most of the variations occurring in the 3′region of the miRNAs. Furthermore, we detected 55 miRNAs that exhibited significant expression differences between laying and non-laying ducks. Gene ontology （GO） and kyoto encyclopedia of genes and genomes （KEGG） enrichment analyses of the potential targets of the differentially expressed miRNAs indicated these miRNAs may play key roles in the egg laying process. Finally, we confirmed the differential expression of 5 miRNAs in the laying and non-laying samples by qRT-PCR. Cumulatively, our work provides the first look at the miRNA expression profile of the duck ovary and provides novel insight into the roles of miRNAs in egg laying and reproduction.展开更多
AIM： To detect the effects of DNA vaccines in combination with duck IFN-γ gene on the protection of ducks against duck hepatitis B virus （DHBV） infection. METHODS： DuIFN-γ cDNA was cloned and expressed in COS-γ...AIM： To detect the effects of DNA vaccines in combination with duck IFN-γ gene on the protection of ducks against duck hepatitis B virus （DHBV） infection. METHODS： DuIFN-γ cDNA was cloned and expressed in COS-γ cells, and the antiviral activity of DuIFN-γ was detected and neutralized by specific antibodies, Ducks were vaccinated with DHBpreS/S DNA alone or coimmunized with plasmid expressing DuIFN-γ. DuIFN-γ mRNA in peripheral blood mononuclear cells （PBMCs） from immunized ducks was detected by semi-quantitative competitive RT-PCR. Anti-DHBpreS was titrated by enzyme-linked immunosorbent assay （EUSA）. DHBV DNA in sera and liver was detected by Southern blot hybridization, after ducks were challenged with high doses of DHBV. RESULTS： DuIFN-γ expressed by COS-γ was able to protect duck fibroblasts against vesicular stomatitis virus （VSV） infection in a dose-dependent fashion, and anti DuIFN-γ antibodies neutralized the antiviral effects. DuIFN-γ in the supernatant also inhibited the release of DHBV DNA from LMH-D2 cells. When ducks were co-immunized with DNA vaccine expressing DHBpreS/S and DuIFN-γ gene as an adjuvant, the level of DuIFN-γ mRNA in PBMCs was higher than that in ducks vaccinated with DHBpreS/S DNA alone. However, the titer of anti-DHBpreS elicited by DHBpreS/S DNA alone was higher than that co-immunized with DuIFN-γ gene and DHBpreS/S DNA. After being challenged with DHBV at high doses, the load of DHBV in sera dropped faster, and the amount of total DNA and cccDNA in the liver decreased more significantly in the group of ducks co-immunized with DuIFN-γ gene and DHBpreS/S DNA than in other groups.展开更多
The duck circovirus （DuCV） infection in sick ducks from Fujian Province was investigated. The liver samples of 43 sick Muscovy ducks with infectious serositis were collected from 12 duck farms in Fujian Province Bas...The duck circovirus （DuCV） infection in sick ducks from Fujian Province was investigated. The liver samples of 43 sick Muscovy ducks with infectious serositis were collected from 12 duck farms in Fujian Province Based on the published sequences of DuCV, two primers were designed for the detection of DuCV and four pairs of primers were designed to amplify four overlapping fragments that cover the complete genome of DuCV. The specific PCR products were amplified from positive samples. The fragments were then cloned into pMD18-T vector and sequenced, and the full length genomic sequence of the FJ0601 isolate of DuCV was obtained. PCR analysis showed that the proportion of ducks which were positive for circovirus was 79% and 10 out of the 12 farms were positive. Sequence analysis showed that the complete genome of DuCV-FJ0601 was 1988 bp and possessed features common to the family Circoviridae which included a stem-loop structure and the Rep protein motifs. Homology analysis showed that FJ0601 isolate of DuCV had 97.3%-97.5% nucleotide sequence identity to all the four Taiwan isolates （TC1/2002, TC2/2002, TC3/2002, TC4/2002）, 82.9% identity to the America （33753-52） isolate and 82.3% identity to the Germany isolate. Phylogenetic analysis with Clustal W, however, showed that FJ0601 isolate of DuCV was on a common branch with Taiwan isolates, and Germany and America isolates belonged to the other branch.展开更多
China has the world’s largest sheep flock and the largest producer of sheep meat by far. However, the nutrient requirements have not been systemically studied and there is a lack of knowledge of nutrient requirement ...China has the world’s largest sheep flock and the largest producer of sheep meat by far. However, the nutrient requirements have not been systemically studied and there is a lack of knowledge of nutrient requirement for meat-type sheep in China.Since 2008, the nutrient requirements of meat-type sheep in China has been systematically investigated. In this review, we introduced the history of studies of nutrient requirements of meat-type sheep in China, summarized the recent advances in nutrient requirements of meat-type sheep, and highlighted the future directions of researches on nutrient requirements of meat-type sheep in China.展开更多
[Objective] To explore artificial insemination technique for production of mule ducks. [Method] Female Cherry Valley ducks were artificially inseminated with semen collected from male Muscovy ducks by massage method a...[Objective] To explore artificial insemination technique for production of mule ducks. [Method] Female Cherry Valley ducks were artificially inseminated with semen collected from male Muscovy ducks by massage method and vagina-insemination method to investigate the effects of insemination dose, insemination interval, insemination time and diluents on fertilization rate. [ Result ] The average fertilization rate was only 39.58%, when the female Cherry Valley ducks naturally mated with the male Muscovy ducks. However, it was increased to 74.79% by artificial insemination. The fertilization rate was 75.24% after semen was diluted by PBS buffer, while it was 75.16% after semen was diluted by Lake＇s buffer; however, there was not significant difference between the fertilization rate of the diluted semen and that of fresh semen （74.10%）. After semen was respectively diluted by PBS buffer and Lake＇s buffer and then stored at 5 ℃ for 24 h, the fertilization rate was low, respectively 23.76% and 34133%. [ Conclusion] Artificial insemination technology can reduce insemination dose and increase fertilization rate in production of mule ducks.展开更多
The effects of different fatty acid(FA) contents in diet on serum parameters,FA compositions of eggs and meat,and liver morphological changes were studied in Shaoxing laying ducks.A total of 264 ducks at 17 weeks were...The effects of different fatty acid(FA) contents in diet on serum parameters,FA compositions of eggs and meat,and liver morphological changes were studied in Shaoxing laying ducks.A total of 264 ducks at 17 weeks were fed a control diet or a diet containing 30 g/kg fish oil(FO),25 g/kg sunflower oil(SO),or 30 g/kg palm oil with 20 g/kg beef tallow(PBO).Malondialdehyde(MDA) content in the liver and the serum of ducks fed the PBO diet was significantly(P<0.05) higher than that of ducks fed the other diets.Triglyceride(TG) and total cholesterol(TC) levels were significantly lower(P<0.05) in ducks fed the FO diet.Serum TC also was lower in ducks fed the SO diet.Superoxide dismutase(SOD) activity was also affected by diets.The contents of polyunsaturated FAs(PUFAs) in eggs and meat were significantly higher(P<0.001) in ducks fed the FO and SO diets than in ducks fed the control diet.The level of C22:6(n-3) FA in ducks fed the FO diet was significantly higher than that in ducks fed the other diets.However,the conversion efficiency of the longer-chain C20:5(n-3) FA was higher than that of C22:6(n-3).Ducks fed the PBO diet exhibited lipid droplet accumulation in the liver.These results demonstrate that a diet enriched with different FAs has strong effects on serum lipid levels and the deposition of PUFAs into tissue lipids.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
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
Background： Feeding behavior study is important for animal husbandry and production. However, few studies were conducted on the feeding behavior and their relationship with feeding efficiency in Pekin ducks. In order...Background： Feeding behavior study is important for animal husbandry and production. However, few studies were conducted on the feeding behavior and their relationship with feeding efficiency in Pekin ducks. In order to investigate the feeding behavior and their relationship with feed efficiency and other economic traits in Pekin ducks, we selected 358 male Pekin ducks and recorded feeding information between 3 to 6 wk of age using automatic electronic feeders, and compared the feeding behavior under different residual feed intake（RFI） levels.Results： We observed that total feed time, daily feed intake and feed intake per meal had strong positive correlations with feed efficiency traits; moreover, strong correlation between feed intake per meal and body weight was found（R=0.32, 0.36）. Daily feeding rate meal and meal duration had weak correlations with feed efficiency（R=0.14~0.15）. The phenotypic correlation of between-meal pauses, with feed efficiency was not observed. When daily changes were analyzed, high RFI ducks had the highest feed consumption over all times, and obvious differences in daily visits were found among different RFI level animals during the middle period; these differences were magnified with age, but there was no difference in daily meal number. Moreover, our data indicate that high RFI birds mainly take their meals at the edge of the population enclosure, where they are more susceptible to environmental interference.Conclusions： Overal, this study suggests that the general feeding behaviors can be accurately measured using automatic electronic feeders and certain feeding behaviors in Pekin ducks are associated with improved feed efficiency.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
A new method for detecting the sequence differences of duck Chromo-helicase-DNA-Binding 1 （ CHD1 ） genes on sex chromosomes Z and W was established by amplifying DNA fragment length poly morphism, which aimed to sol...A new method for detecting the sequence differences of duck Chromo-helicase-DNA-Binding 1 （ CHD1 ） genes on sex chromosomes Z and W was established by amplifying DNA fragment length poly morphism, which aimed to solve some technical problems, such as the sex identification with nondamage, the misclassifc rate of artificial sex identification during embryonic period, and the injury caused by anal reversal identification method during neonatal period. The im- proved sex identification method was developed by DNA amplified fragment length polymorphism by using CHD1 gene sequence in bird. The sex identification PCR primers YPF/YPR were used, and the PCR product was cloned, sequenced and blasted; and the effectiveness and accuracy of this method were verified through liv- ing examples. 2% agarose gel electrophoresis was used to distinguish 495 bp CHD1-Z and 351 bp CHD1-W obtained by primer YPF/YPR. The female （ZW） dis- played two visible bands; while male （ZZ） had only one single band. It was proved that this method for detecting the sequence differences of duck CHD1 gene was visual and reliable, and the molecular marker provided was effective and precise in the sex molecular biological identification of domesticated duck in China.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
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
基金supported by the National Key R&D Program of China(2022YFD1301800)grants from the National Natural Science Foundation of China(grant number 32502899)+1 种基金China Agriculture Research System of MOF and MARA(CARS-42-10)the Agricultural Science and Technology Innovation Program of CAAS(CAAS-ASTIP-2023-IFR-13)。
文摘Background Selective breeding for disease resistance is an effective strategy to control duck hepatitis A virus type 3(DHAV-3)in waterfowl.However,the mechanism underlying resistance remains poorly understood,particularly those associated with antioxidant defense,intestinal development and host-microbiota interactions.Method A total of 1001-day-old Pekin ducklings were used in this study with 50 DHAV-3 susceptible and resistant ducks,respectively.Samples were collected at 7 days post-hatching(D7),D21 and D42,10 birds per group.We compared DHAV-3 resistant and susceptible ducks during early development with respect to immune organ indices,antioxidant capacity,intestinal morphology,barrier-related gene expression and cecal microbiota.Result Resistant ducks exhibited higher spleen indices and stronger antioxidant capacity,characterized by increased superoxide dismutase,reduced glutathione,and total antioxidant capacity,along with lower malondialdehyde levels at D7 and D21.In contrast,susceptible ducks showed compensatory thymus hypertrophy and delayed development of antioxidant defense and intestinal maturation.Ileal morphology revealed greater villus height and width with more regular arrangement in resistant ducks at D7,whereas these differences diminished at D21 and D42.Gene expression analysis demonstrated higher early expression of the tight junction proteins CLDN1 and CLDN3 in resistant ducks,while susceptible ducks displayed elevated MUC2 and OCLN,suggesting stress induced compensatory responses.Cecal microbiota analysis revealed distinct colonization patterns in early development.Resistant ducks were enriched with Firmicutes and beneficial genera such as Enterococcus and Lactobacillus,whereas susceptible ducks harbored higher abundances of Bacteroidota and potentially opportunistic taxa.Microbial diversity increased with age in both groups,but resistant ducks displayed more orderly succession and enrichment of SCFA producing genera,including Subdoligranulum and Phascolarctobacterium,which positively correlated with plasma antioxidant indices.Conclusion DHAV-3 resistant ducks exhibit early advantages in antioxidant defense,intestinal barrier development and colonization by beneficial microbiota,which collectively contribute to enhanced disease resistance.These findings highlight the synergistic roles of host physiology and gut microbiota in shaping resistance.In the future,integrating genomic selection with microbiota modulation and antioxidant interventions may accelerate the breeding of highly resistant duck lines and provide scientific evidence and practical strategies for controlling duck viral hepatitis.
基金Work in our laboratory was supported by the Fund for China Agricultural Research System(CARS-42-13)the Science and Technology Program of Guangdong Province(2011A020102009 and 2016A020210043)Operating Funds for Guangdong Provincial Key Laboratory of Animal Breeding and Nutrition(2014B030301054)
文摘The demand for duck meat, duck eggs, and associated products is increasing each year. Classic and modern selection programs have been applied to enhance the economic traits of ducks to satisfy the requirements of consumers and enhance the incomes of producers. The nutritional requirements of unselected ducks may not be adequate, however, to fulfill the potential productivity performance of modern birds, including both meat-type and egg-type ducks. In particular, an imbalanced diet is associated with low productive performance and signs of nutritional deficiency（if insufficient nutrients are supplied）, as well as with high feed costs and manure problems that reflect flock health and welfare（if excessive nutrients are supplied）. Thus, the main aim of this review is to summarize the results of previous studies that estimated the nutrient requirements of meat-type and egg-type ducks in order to evaluate current knowledge and to identify further issues that need to be addressed. In addition,the results obtained in previous studies are compared in order to understand how to lower commercial feed costs,fulfill the genetic potential of selected ducks, protect the environment from pollution, and satisfy the welfare and health needs of ducks.
基金National Key Research and Development Program of China(2021YFC2103003)National Natural Science Foundation of China(31972604)+1 种基金Jinan Introductory Innovation Team Project(No.202228037)China Postdoctoral Science Foundation(2023M730998).
文摘Background AflatoxinB1(AFB_(1))is a prevalent contaminant in agricultural products,presenting significant risks to animal health.CotA laccase from Bacillus licheniformis has shown significant efficacy in degrading mycotoxins in vitro test.The efficacy of Bacillus CotA laccase in animals,however,remains to be confirmed.A 2×2 factorial design was used to investigate the effects of Bacillus CotA laccase level(0 or 1 U/kg),AFB_(1) challenge(challenged or unchal-lenged)and their interactions on ducks.The purpose of this study was to evaluate the efficacy of Bacillus CotA laccase in alleviatingAFB_(1) toxicosis of ducks.Results Bacillus CotA laccase alleviatedAFB_(1)-induced declines in growth performance of ducks accompanied by improved average daily gain(ADG)and lower feed/gain ratio(F/G).Bacillus CotA laccase amelioratedAFB_(1)-induced gut barrier dysfunctions and inflammation testified by increasing the jejunal villi height/crypt depth ratio(VH/CD)and the mRNA expression of tight junction protein 1(TJP1)and zonula occluden-1(ZO-1)as well as decreasing the expression of inflammation-related genes in the jejunum of ducks.Amino acid metabolome showed that Bacillus CotA laccase amelioratedAFB_(1)-induced amino acid metabolism disorders evidenced by increasing the level of glu-tamic acid in serum and upregulating the expression of amino acid transport related genes in jejunum of ducks.Bacil-lus CotA laccase amelioratedAFB_(1)-induced liver injury testified by suppressing oxidative stress,inhibiting apoptosis,and downregulating the expression of hepatic metabolic enzyme related genes of ducks.Moreover,Bacillus CotA laccase degradedAFB_(1) in digestive tract of ducks,resulting in the reduced absorption level ofAFB_(1) across intestinal epithelium testified by the decreased level ofAFB_(1)-DNA adduct in the liver,and the reduced content ofAFB_(1) residues in liver and feces of ducks.Conclusions Bacillus CotA laccase effectively improved the growth performance,intestinal health,amino acid metabolism and hepatic aflatoxin metabolism of ducks fedAFB_(1) diets,highlighting its potential as an efficient and safe feed enzyme forAFB_(1) degradation in animal production.
基金Supported by Project of Jiangsu Agri-animal Husbandry Vocational College(NSFZN1309)~~
文摘In order to investigate the effects of probiotics on growth performance, blood biochemical indexes and economic benefits of Cherry Valley ducks, different probiotics were added into the feed of Cherry Valley ducks. Total 240 1-d-old Cherry Valley ducks were selected, and they were randomly divided into 4 groups, including 1 control group and 3 treatment groups. There were 3 replicates for each group and there were 20 ducks for each replicate. The ducks in the control group were fed the basal diet, and the ducks in the 3 treatment groups were fed the basal diet added with Lactobacillus, Bacillus natto and florfenicol, respectively. The test lasted for 42 d. The results showed that the addition of Lactobacillus and Bacillus natto could improve the average daily weight gain and final average weight （P〈0.05） of Cherry Valley ducks, and reduce the glutamic-pyruvic transaminase ac- tivity, alkaline phosphatase activity and serum urinary nitrogen content in duck blood （P〈0.05） and reduce the creatinine content and total cholesterol content in Cherry Valley ducks （P〉0.05）; at the same time, adding probiotics to feed could also in- crease the grass economic benefits of Cherry Valley ducks. In overall, the effects of adding probiotics were better than those of adding antibiotic.
基金supported by the grants from the National Institutes of Health(1R01AI101028-01A1)the Office of Health,Infectious Diseases and Nutrition in the Bureau for Global Health,U.S.Agency for International Development(GHA-G-00-06-00001)
文摘Agro-ecological conditions associated with the spread and persistence of highly pathogenic avian inlfuenza （HPAI） are not well understood, but the trade of live poultry is suspected to be a major pathway. Although market chains of live bird trade have been studied through indirect means including interviews and questionnaires, direct methods have not been used to identify movements of individual poultry. To bridge the knowledge gap on quantitative movement and transportation of poultry, we introduced a novel approach for applying telemetry to document domestic duck movements from source farms at Poyang Lake, China. We deployed recently developed transmitters that record Global Positioning System （GPS） locations and send them through the Groupe Spécial Mobile （GSM） cellular telephone system. For the ifrst time, we were able to track individually marked ducks from 3 to 396 km from their origin to other farms, distribution facilities, or live bird markets. Our proof of concept test showed that the use of GPS-GSM transmitters may provide di-rect, quantitative information to document the movement of poultry and reveal their market chains. Our ifndings provide an initial indication of the complexity of source-market network connectivity and highlight the great potential for future telemetry studies in poultry network analyses.
基金supported by the National Natural Science Foundation of China (31101705)the Natural Science Foundation of Jiangsu Province, China (BK2010454)the Agricultural Science and Technology Independent Innovation Fund of Jiangsu Province, China (cx(09)116 and cx(11)1028)
文摘MicroRNAs （miRNAs）, which post-transcriptionally regulate gene expression by binding to the 3′untranslated region of mRNAs to either inhibit or enhance translation, are involved in diverse biological processes. The use of high-throughput Solexa sequencing plays important roles in the discovery of miRNAs. In this study, we used high-throughput Solexa sequencing to identify novel duck miRNAs and compare the miRNA expression profiles in laying and non-laying duck ovaries. Using a bioinformatic analysis, we discovered 86 potential duck miRNAs similar to known chicken miRNAs and 43 unique sequences that matched known miRNAs of other species. We also found that miRNA variations and isoforms were widespread in our two RNA libraries, with most of the variations occurring in the 3′region of the miRNAs. Furthermore, we detected 55 miRNAs that exhibited significant expression differences between laying and non-laying ducks. Gene ontology （GO） and kyoto encyclopedia of genes and genomes （KEGG） enrichment analyses of the potential targets of the differentially expressed miRNAs indicated these miRNAs may play key roles in the egg laying process. Finally, we confirmed the differential expression of 5 miRNAs in the laying and non-laying samples by qRT-PCR. Cumulatively, our work provides the first look at the miRNA expression profile of the duck ovary and provides novel insight into the roles of miRNAs in egg laying and reproduction.
基金Supported by the Major State Basic Research Development Program of China, 973 Program, No. G2002CB512803the National Natural Science Foundation of China, No. 30070693the Science and Technology Foundation of Shanghai, No. 02DJ14002
文摘AIM： To detect the effects of DNA vaccines in combination with duck IFN-γ gene on the protection of ducks against duck hepatitis B virus （DHBV） infection. METHODS： DuIFN-γ cDNA was cloned and expressed in COS-γ cells, and the antiviral activity of DuIFN-γ was detected and neutralized by specific antibodies, Ducks were vaccinated with DHBpreS/S DNA alone or coimmunized with plasmid expressing DuIFN-γ. DuIFN-γ mRNA in peripheral blood mononuclear cells （PBMCs） from immunized ducks was detected by semi-quantitative competitive RT-PCR. Anti-DHBpreS was titrated by enzyme-linked immunosorbent assay （EUSA）. DHBV DNA in sera and liver was detected by Southern blot hybridization, after ducks were challenged with high doses of DHBV. RESULTS： DuIFN-γ expressed by COS-γ was able to protect duck fibroblasts against vesicular stomatitis virus （VSV） infection in a dose-dependent fashion, and anti DuIFN-γ antibodies neutralized the antiviral effects. DuIFN-γ in the supernatant also inhibited the release of DHBV DNA from LMH-D2 cells. When ducks were co-immunized with DNA vaccine expressing DHBpreS/S and DuIFN-γ gene as an adjuvant, the level of DuIFN-γ mRNA in PBMCs was higher than that in ducks vaccinated with DHBpreS/S DNA alone. However, the titer of anti-DHBpreS elicited by DHBpreS/S DNA alone was higher than that co-immunized with DuIFN-γ gene and DHBpreS/S DNA. After being challenged with DHBV at high doses, the load of DHBV in sera dropped faster, and the amount of total DNA and cccDNA in the liver decreased more significantly in the group of ducks co-immunized with DuIFN-γ gene and DHBpreS/S DNA than in other groups.
基金Shandong Provincial Excellent YoungScientist Fund (2004BS06002)Innovation Fund ofShandong Agricultural University
文摘The duck circovirus （DuCV） infection in sick ducks from Fujian Province was investigated. The liver samples of 43 sick Muscovy ducks with infectious serositis were collected from 12 duck farms in Fujian Province Based on the published sequences of DuCV, two primers were designed for the detection of DuCV and four pairs of primers were designed to amplify four overlapping fragments that cover the complete genome of DuCV. The specific PCR products were amplified from positive samples. The fragments were then cloned into pMD18-T vector and sequenced, and the full length genomic sequence of the FJ0601 isolate of DuCV was obtained. PCR analysis showed that the proportion of ducks which were positive for circovirus was 79% and 10 out of the 12 farms were positive. Sequence analysis showed that the complete genome of DuCV-FJ0601 was 1988 bp and possessed features common to the family Circoviridae which included a stem-loop structure and the Rep protein motifs. Homology analysis showed that FJ0601 isolate of DuCV had 97.3%-97.5% nucleotide sequence identity to all the four Taiwan isolates （TC1/2002, TC2/2002, TC3/2002, TC4/2002）, 82.9% identity to the America （33753-52） isolate and 82.3% identity to the Germany isolate. Phylogenetic analysis with Clustal W, however, showed that FJ0601 isolate of DuCV was on a common branch with Taiwan isolates, and Germany and America isolates belonged to the other branch.
基金supported by the China Agriculture Research System of MOF and MARA(CARS-38)the Project of Exploitation and Utilization of High Quality Green and Rough Feed Resources,China(16200157)the Inner Mongolia Science and Technology Agency,China(2020GG0058)。
文摘China has the world’s largest sheep flock and the largest producer of sheep meat by far. However, the nutrient requirements have not been systemically studied and there is a lack of knowledge of nutrient requirement for meat-type sheep in China.Since 2008, the nutrient requirements of meat-type sheep in China has been systematically investigated. In this review, we introduced the history of studies of nutrient requirements of meat-type sheep in China, summarized the recent advances in nutrient requirements of meat-type sheep, and highlighted the future directions of researches on nutrient requirements of meat-type sheep in China.
文摘[Objective] To explore artificial insemination technique for production of mule ducks. [Method] Female Cherry Valley ducks were artificially inseminated with semen collected from male Muscovy ducks by massage method and vagina-insemination method to investigate the effects of insemination dose, insemination interval, insemination time and diluents on fertilization rate. [ Result ] The average fertilization rate was only 39.58%, when the female Cherry Valley ducks naturally mated with the male Muscovy ducks. However, it was increased to 74.79% by artificial insemination. The fertilization rate was 75.24% after semen was diluted by PBS buffer, while it was 75.16% after semen was diluted by Lake＇s buffer; however, there was not significant difference between the fertilization rate of the diluted semen and that of fresh semen （74.10%）. After semen was respectively diluted by PBS buffer and Lake＇s buffer and then stored at 5 ℃ for 24 h, the fertilization rate was low, respectively 23.76% and 34133%. [ Conclusion] Artificial insemination technology can reduce insemination dose and increase fertilization rate in production of mule ducks.
基金Project supported by the Key Technology Project of Zhejiang Province(No. 2007C14023)the Earmarked Fund for Modern Agro-industry Technology Research System of China (No. nycytx-45-02)
文摘The effects of different fatty acid(FA) contents in diet on serum parameters,FA compositions of eggs and meat,and liver morphological changes were studied in Shaoxing laying ducks.A total of 264 ducks at 17 weeks were fed a control diet or a diet containing 30 g/kg fish oil(FO),25 g/kg sunflower oil(SO),or 30 g/kg palm oil with 20 g/kg beef tallow(PBO).Malondialdehyde(MDA) content in the liver and the serum of ducks fed the PBO diet was significantly(P<0.05) higher than that of ducks fed the other diets.Triglyceride(TG) and total cholesterol(TC) levels were significantly lower(P<0.05) in ducks fed the FO diet.Serum TC also was lower in ducks fed the SO diet.Superoxide dismutase(SOD) activity was also affected by diets.The contents of polyunsaturated FAs(PUFAs) in eggs and meat were significantly higher(P<0.001) in ducks fed the FO and SO diets than in ducks fed the control diet.The level of C22:6(n-3) FA in ducks fed the FO diet was significantly higher than that in ducks fed the other diets.However,the conversion efficiency of the longer-chain C20:5(n-3) FA was higher than that of C22:6(n-3).Ducks fed the PBO diet exhibited lipid droplet accumulation in the liver.These results demonstrate that a diet enriched with different FAs has strong effects on serum lipid levels and the deposition of PUFAs into tissue lipids.
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 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 Scientific Supporting Projects of China(2015BAD03B06)National Waterfowl-industry Technology Research System(CARS-42)the Program for Changjiang Scholars and Innovative Research Team in University(IRT_15R62)
文摘Background： Feeding behavior study is important for animal husbandry and production. However, few studies were conducted on the feeding behavior and their relationship with feeding efficiency in Pekin ducks. In order to investigate the feeding behavior and their relationship with feed efficiency and other economic traits in Pekin ducks, we selected 358 male Pekin ducks and recorded feeding information between 3 to 6 wk of age using automatic electronic feeders, and compared the feeding behavior under different residual feed intake（RFI） levels.Results： We observed that total feed time, daily feed intake and feed intake per meal had strong positive correlations with feed efficiency traits; moreover, strong correlation between feed intake per meal and body weight was found（R=0.32, 0.36）. Daily feeding rate meal and meal duration had weak correlations with feed efficiency（R=0.14~0.15）. The phenotypic correlation of between-meal pauses, with feed efficiency was not observed. When daily changes were analyzed, high RFI ducks had the highest feed consumption over all times, and obvious differences in daily visits were found among different RFI level animals during the middle period; these differences were magnified with age, but there was no difference in daily meal number. Moreover, our data indicate that high RFI birds mainly take their meals at the edge of the population enclosure, where they are more susceptible to environmental interference.Conclusions： Overal, this study suggests that the general feeding behaviors can be accurately measured using automatic electronic feeders and certain feeding behaviors in Pekin ducks are associated with improved feed efficiency.
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 the National Natural Science Foundation of China(31172194)The Science and Technology Support Program of Jiangsu Province(BE2011329)The Variety Innovation Project of Modern Agriculture(CX(11)1030)
文摘A new method for detecting the sequence differences of duck Chromo-helicase-DNA-Binding 1 （ CHD1 ） genes on sex chromosomes Z and W was established by amplifying DNA fragment length poly morphism, which aimed to solve some technical problems, such as the sex identification with nondamage, the misclassifc rate of artificial sex identification during embryonic period, and the injury caused by anal reversal identification method during neonatal period. The im- proved sex identification method was developed by DNA amplified fragment length polymorphism by using CHD1 gene sequence in bird. The sex identification PCR primers YPF/YPR were used, and the PCR product was cloned, sequenced and blasted; and the effectiveness and accuracy of this method were verified through liv- ing examples. 2% agarose gel electrophoresis was used to distinguish 495 bp CHD1-Z and 351 bp CHD1-W obtained by primer YPF/YPR. The female （ZW） dis- played two visible bands; while male （ZZ） had only one single band. It was proved that this method for detecting the sequence differences of duck CHD1 gene was visual and reliable, and the molecular marker provided was effective and precise in the sex molecular biological identification of domesticated duck in China.
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(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.
