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
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
Some H5 viruses isolated in poultry or wild birds between 2020 and 2021 were found to be antigenically different from the vaccine strains(H5-Re11 and H5-Re12) used in China. In this study, we generated three new recom...Some H5 viruses isolated in poultry or wild birds between 2020 and 2021 were found to be antigenically different from the vaccine strains(H5-Re11 and H5-Re12) used in China. In this study, we generated three new recombinant vaccine seed viruses by using reverse genetics and used them for vaccine production. The vaccine strain H5-Re13 contains the hemagglutinin(HA) and neuraminidase(NA) genes of an H5 N6 virus that bears the clade 2.3.4.4 h HA gene, H5-Re14 contains the HA and NA genes of an H5 N8 virus that bears the clade 2.3.4.4 b HA gene, and H7-Re4 contains the HA and NA genes of H7 N9 virus detected in 2021. We evaluated the protective efficacy of the novel H5/H7 trivalent inactivated vaccine in chickens, ducks, and geese. The inactivated vaccine was immunogenic and induced substantial antibody responses in the birds tested. Three weeks after vaccination, chickens were challenged with five different viruses detected in 2020 and 2021: three viruses(an H5 N1 virus, an H5 N6 virus, and an H5 N8 virus) bearing the clade 2.3.4.4 b HA gene, an H5 N6 virus bearing the clade 2.3.4.4 h HA gene, and an H7 N9 virus. All of the control birds shed high titers of virus and died within 4 days post-challenge, whereas the vaccinated chickens were completely protected from these viruses. Similar protective efficacy against H5 viruses bearing the clade 2.3.4.4 h or 2.3.4.4 b HA gene was observed in ducks and geese. Our study indicates that the newly updated H5/H7 vaccine can provide solid protection against the H5 and H7 N9 viruses that are currently circulating in nature.展开更多
The 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
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
O6-methylguanine DNA methyltransferase (O6-AT) is an enzyme for the repair of the promutagenic structure, O6-aIkylguanine, from alkylated DNA, therefore low activity of O6-AT is involved in the predisposition of tissu...O6-methylguanine DNA methyltransferase (O6-AT) is an enzyme for the repair of the promutagenic structure, O6-aIkylguanine, from alkylated DNA, therefore low activity of O6-AT is involved in the predisposition of tissues to some nitrosamines and the development of cancer. The levels of O6-AT in livers of ducks from Qidong (Qd), a high incidence area of liver cancer, and from Qingpu(Qp), a relatively low incidence area were determined in this study. The results showed that the activity of O6-AT was higher in Qp than in Qd. It suggested that some nitrosamine in Qd might be one of factors responsible for the higher incidence of ducks liver cancer, because these ducks were more sensitive to nitrosa-mine.展开更多
[ Objective] To clone and analyze the intedeukin-2 (IL.2) gene in Gaoyou ducks. [ Method] With total RNA isolated from peripheral lym- phocytes of Gaoyou ducks as templates, one pair of primers was designed accordin...[ Objective] To clone and analyze the intedeukin-2 (IL.2) gene in Gaoyou ducks. [ Method] With total RNA isolated from peripheral lym- phocytes of Gaoyou ducks as templates, one pair of primers was designed according to the known IL-2 gene sequence in ducks. The IL-2 DNA was amplified by the RT-PCR and inserted into pGEM-T-easy vector. Then the positive recombinant plasmid was sequenced. [ Result] The amplified target fragment was 433 bp with the correct size as theoretically expected. The open reading frame (ORF) was 423 bp encoding a precursor protein with 140 amino acids which consisted of a signal peptide composed of 21 amino acids and a mature peptide composed of 119 amino acids. The pro- tein was approximately 13.66 kDa and contained one N-glycosylation site. The sequence of IL-2 gene of Gaoyou duck had 99.8% nucleotide homol- ogy to that of Anas platyrhynchos duck, Gushi duck and Shaoxing duck, respectively. It also had 99.3% nucleotide homology to that of Guangzhou duck. [ Conclusion] The coding region of IL-2 gene of ducks is highly conserved.展开更多
To study the immune effect of recombinant avian influenza virus H5 subtype bivalent inactivated vaccine ( HSN1, Re-6 strain + Re-4 strain) and to provide the basis for formulating reasonable immune procedure of avi...To study the immune effect of recombinant avian influenza virus H5 subtype bivalent inactivated vaccine ( HSN1, Re-6 strain + Re-4 strain) and to provide the basis for formulating reasonable immune procedure of avian influenza vaccine in clinical practice. A total of 12 batches of vaccines from three companies were used for the iannune of SPF chickens and SPF ducks. Each chicken or duck serum was separately collected every 3 weeks until the immunization up to the 24^th week. The serum antibody titers of Re-6 and Re-4 were detected. The results showed that the HI titers of the inoculated SPF chickens and SPF ducks roached the peak when the immune time were the 6^th and 3^rd week after the first immunization respectively; then the titer decreased gradually as time prolonged; the highest titer of SPF chickens was greater than that of SPF ducks; the high titer duration of SPF chickens were longer than that of SPF ducks ; and all the vaccines from the three companies showed a good immune effect.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
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
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
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 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 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O6-methylguanine DNA methyltransferase (O6-AT) is an enzyme for the repair of the promutagenic structure, O6-aIkylguanine, from alkylated DNA, therefore low activity of O6-AT is involved in the predisposition of tissues to some nitrosamines and the development of cancer. The levels of O6-AT in livers of ducks from Qidong (Qd), a high incidence area of liver cancer, and from Qingpu(Qp), a relatively low incidence area were determined in this study. The results showed that the activity of O6-AT was higher in Qp than in Qd. It suggested that some nitrosamine in Qd might be one of factors responsible for the higher incidence of ducks liver cancer, because these ducks were more sensitive to nitrosa-mine.
基金supported by the Natural Science Funds of Jiangsu Province(BK2009701)Education Reform Research Funds of Yangzhou University in 2009
文摘[ Objective] To clone and analyze the intedeukin-2 (IL.2) gene in Gaoyou ducks. [ Method] With total RNA isolated from peripheral lym- phocytes of Gaoyou ducks as templates, one pair of primers was designed according to the known IL-2 gene sequence in ducks. The IL-2 DNA was amplified by the RT-PCR and inserted into pGEM-T-easy vector. Then the positive recombinant plasmid was sequenced. [ Result] The amplified target fragment was 433 bp with the correct size as theoretically expected. The open reading frame (ORF) was 423 bp encoding a precursor protein with 140 amino acids which consisted of a signal peptide composed of 21 amino acids and a mature peptide composed of 119 amino acids. The pro- tein was approximately 13.66 kDa and contained one N-glycosylation site. The sequence of IL-2 gene of Gaoyou duck had 99.8% nucleotide homol- ogy to that of Anas platyrhynchos duck, Gushi duck and Shaoxing duck, respectively. It also had 99.3% nucleotide homology to that of Guangzhou duck. [ Conclusion] The coding region of IL-2 gene of ducks is highly conserved.
基金Supported by Shandong Winning Project of Quality Monitoring of Avian Influenza Vaccine
文摘To study the immune effect of recombinant avian influenza virus H5 subtype bivalent inactivated vaccine ( HSN1, Re-6 strain + Re-4 strain) and to provide the basis for formulating reasonable immune procedure of avian influenza vaccine in clinical practice. A total of 12 batches of vaccines from three companies were used for the iannune of SPF chickens and SPF ducks. Each chicken or duck serum was separately collected every 3 weeks until the immunization up to the 24^th week. The serum antibody titers of Re-6 and Re-4 were detected. The results showed that the HI titers of the inoculated SPF chickens and SPF ducks roached the peak when the immune time were the 6^th and 3^rd week after the first immunization respectively; then the titer decreased gradually as time prolonged; the highest titer of SPF chickens was greater than that of SPF ducks; the high titer duration of SPF chickens were longer than that of SPF ducks ; and all the vaccines from the three companies showed a good immune effect.
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 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.