Mature Ducks Research Articles

Isolation and characterization of a duck reovirus strain from mature ducks in China

In 2018, a disease characterized by splenic hemorrhage and necrosis killed ducks in a duck farm in Guangxi province, China. A duck reovirus strain was isolated from the tissues of the dead ducks by inoculating duck embryos and BHK-21 cells. Electron microscopy of the cultured the isolate showed that the viral particles were nearly round in shape and approximately 70 nm in diameter, and they were designated DRV-GL18. Sequence analysis showed that the GL18 strain viral genome was 23,419 nt in length and had 10 dsRNA segments. Phylogenetic analysis of cDNA amplicons of segments encoding the protein σC which are outer capsid proteins showed that the isolate belongs to the branch of the epidemic strains of duck reovirus. The Recombination Detection Program (RDP) and SimPlot program analyses suggested potential genetic recombination events in the M2 segments. Pathogenicity experiments revealed that GL18 produced severe hemorrhaging in livers and necrosis in the spleen of infected SPF ducklings. A death rate of 50% in the experimental ducklings was calculated during the first 7 d, and the rest of the ducklings were observed to undergo spleen necrosis. These data suggested that GL18 is a duck reovirus isolate with severer pathogenicity, and it could be a candidate for development of vaccine. This is the first reported isolation of duck reovirus from mature ducks.

Cover Image

The cover image is based on the Original Article Duck hepatitis A virus 1 has lymphoid tissue tropism altering the organic immune responses of mature ducks by Anchun Cheng et al., https://doi.org/10.1111/tbed.13966

Crop Morpho-Histological Peculiarities in Domesticated Pigeons (Columba livia domestica), Cattle Egret (Bubulcus ibis) and Domesticated Ducks (Anas platyrhynchos domestica)

The crop architecture varies among different avian species consistent with their feeding habits. Therefore, twenty-one of mature healthy male pigeons (granivorous), cattle egrets (carnivorous), and ducks (omnivorous), seven per species, were utilized for the histological, immunohistochemical, and ultrastructural analyses. Histologically, the mucosal folds were covered by non-keratinized stratified squamous epithelium in the three investigated species. The mucosal glands are only peculiar to the crops of the cattle egrets as well as the ducks, while the pigeons' crops were devoid of any secretory units. Morphometrically, the optical densities of the Alcian blue (AB) and periodic acid Schiff (PAS) reactions in the secretory glands, the area % of collagen fibers, the thickness of the tunica musculosa were measured and declared significant differences among the three studied avian species. Immunohistochemical reaction revealed ki-67 immuno-positive reactivity in the nuclei of basal cell layers of the crop epithelium in pigeons only. Regarding ultrastructure investigation, the covering epithelium of all studied species had been shown to be the basal layer of cuboidal to tall columnar cells with desmosomal junctions at the level of their cellular interdigitation, intermediate layers of large irregular polygonal cells with obviously increased cytokeratin filaments especially in the ducks and cellular interdigitation in between. The superficial layer of flat-shaped cells in the three investigated species manifested by desmosomal junctions in between but at the level of the surface squamous cells of the superficial layer, a fine lateral process is only inspected in the pigeons. In conclusion, the crop glands characterized by supranuclear electron dense secretory granules in the cattle egrets and electron-lucent in ducks.

Duck hepatitis A virus 1 has lymphoid tissue tropism altering the organic immune responses of mature ducks.

Duck hepatitis A virus 1 (DHAV-1) is a highly prevalent pathogen within adult ducks causing acute as well as chronic hepatitis which closely emulates the progression of human hepatitis. However, the underlying mechanisms of DHAV-1 persistence and the pathogenesis of chronic liver disease are not well defined. The association between hematopoietic reservoirs of virus and persistent infection is increasingly concerning. Here, we explored the ability of lymphoid replication of DHAV-1 and the effect on immunity. We found that DHAV-1 was able to infect and replicate productively in the lymphoid organs of model ducks, persisting over 6months. Moreover, a significant correlation of viral loads between these organs and blood was found, documenting a major contribution of lymphoid replication to DHAV-1 viraemia. Along with viral replication, the mRNA of PRRs and immune-related cytokines was up-regulated in these organs during the early phase of infection, showing tissue-dependent expression patterns but all inclining towards Th2 responses due to the consistently higher level of IL-4 than IL-2 and IFN-γ. Additionally, the expression of CCL19, CCL21, MHC-I and MHC-II, which are involved in T cell homing to the periphery and priming, was dysmodulated. Our data indicate that DHAV-1 possesses lymphoid tissue tropism, contributing to persistent infection and chronic hepatitis via altering the early endogenous transcription of immune-related genes and thereby perturbing organic immunity. These results may be useful to develop novel strategies to treat chronic viral hepatitis based on stimulation of the early innate system and regulation of T-cell trafficking.

Effect of hybrid rice varieties on growth and development of broilers and ducks

Three experiments (Exp. 1, n = 144 broilers [Ross × Ross]; Exp. 2, n = 118 mallard ducklings [Anas platyrhynchos]; and Exp. 3, n = 75 mature mallard ducks) were conducted to determine the effects of 3 levels of unmilled hybrid rice on growth performance and organ and gastrointestinal tract development. The dietary treatments were 1) corn-soybean meal (basal), 2) basal + 5% hybrid rice, and 3) basal + 10% hybrid rice for Exp. 1 to 3, respectively. One bird from each pen in Exp. 1 (n = 24) and all the birds in Exp. 2 (n = 118) and Exp. 3 (n = 75) were randomly selected and euthanized to determine linear measurements and organ and gastrointestinal tract weight. In Exp. 1 and 2, birds fed 10% rice experienced slower growth (P < 0.05) than birds fed the basal diet. In Exp. 3, the addition of rice did not affect growth performance. Rice addition did not affect organ length or weight (P > 0.05) in Exp. 1. However, birds fed 5% rice had significantly increased (P < 0.05) pancreas, ileum, and jejunum weights in Exp. 2, and 10% rice significantly increased (P < 0.05) liver weight in Exp. 3. The addition of 10% unmilled rice to broiler and duck diets may reduce growth performance.

Macroanatomical Structure of the Lumbosacral Plexus and its Branches in the Indigenous Duck

The present study was carried out to determine the morphological structure and the branches of the lumbosacral plexus in the indigenous duck (Anas platyrhynchos domesticus). Six mature indigenous ducks were used in this study. After administering an anesthetic to the birds, the body cavities were opened. The nerves of the lumbosacral plexus were dissected separately and photographed. The lumbosacral plexus consisted of lumbar and sacral plexus innervated to the hind limb. The lumbar plexus was formed by the union of three roots of spinal nerves that included last two and first sacral spinal nerve. Among three roots, second (middle) root was the highest in diameter and the last root was least in diameter. We noticed five branches of the lumbar plexus which included obturator, cutaneous femoral, saphenus, cranial coxal, and the femoral nerve. The six roots of spinal nerves, which contributed to form three trunks, formed the sacral plexus of duck. The three trunks united medial to the acetabular foramen and formed a compact, cylindrical bundle, the ischiatic nerve. The principal branches of the sacral plexus were the tibial and fibular nerves that together made up the ischiatic nerve. Other branches were the caudal coxal nerve, the caudal femoral cutaneous nerve and the muscular branches. This study was the first work on the lumbosacral plexus of duck and its results may serve as a basis for further investigation on this subject.

Virologic and Immunologic Characteristics in Mature Ducks with Acute Duck Hepatitis A Virus 1 Infection.

Duck hepatitis A virus 1 (DHAV-1) infection in mature ducks has previously been proposed as a small-animal model for human hepatitis A. However, basic research on the outcome of DHAV-1 infection in mature ducks is limited. Here, we examined the course of viremia, the characteristics of antibody responses, and the profiles of plasma cytokines in mature ducks infected with DHAV-1. During the course of infection, the viremia was detectable soon after infection and persisted for 196 days, however, the ducks presented as clinically asymptomatic. Specific and timely immunoglobulin G (IgG), IgM, and IgA1 responses were elicited. At the same time, extensive inhibition of viral replication was observed with increasing IgG concentration. With respect to pattern-recognition receptors, TLR-7 was mainly involved in triggering the innate defense against the DHAV-1 infection. In addition, plasma immune analytes were measured and were determined to have bidirectional roles in virus clearance. It was concluded that DHAV-1 spreads quickly in blood. The spontaneous clearance of DHAV-1 during asymptomatic infection in mature ducks depends on the cooperation of timely antibody responses and alert innate immune responses. Moreover, the delayed clearance may be associated with a weak interferon-γ-producing CD8+ T cell response. This study allows us to reveal the mechanism of clearance and persistence of DHAV-1 infection in mature ducks. We anticipate that it will provide a basis for future studies focused on defining the nature mechanisms involved in the clearance and persistence of human hepatitis virus.

MACROANATOMICAL ASPECTS OF BRACHIAL PLEXUS AND ITS BRANCHES IN THE INDIGENOUS DUCK

The injury to the peripheral nervous system is common clinical problem especially injury to the wing is the most common in birds. The present study aimed to document the detailed features of the morphological structure and the innervations areas of the brachial plexus in indigenous duck (Anas platyrhynchos domesticus). A total of six mature indigenous ducks (three of them were male and three were female) were used in this study. After administering an anesthetic to the birds, the body cavities were opened. The birds were fixed with formaldehyde after draining of the blood. The nerves of the brachial plexus were dissected separately and photographed. The brachial plexus was formed by the union of the ventral branches of 14thand 15th cervical spinal nerve and 1st, 2nd and 3rd thoracic spinal nerves, which were confirmed by palpation and counting the cervical vertebrae. Present study revealed that few small and large branches originated from brachial plexus and innervated into the specific muscles and their adjacent structure. Five nerve roots formed three nerve trunks in the duck, which constitute the dorsal and ventral cords. The pectoral trunk and median-ulnar nerve originated from ventral cord, while dorsal cord gives axillary nerve continued as a radial nerve into the wing of duck. The axillary nerve innervated into to skin of the dorsal side of the wing and shoulder deltoideous muscles, coracobrachialis muscles and propatagiasis cervical muscles. The radial nerve innervated to the humuro-brachial and triceps muscles, extensor carpi radial and supinator muscles. The ulnar nerve innervated extensor aspect of joint, flexor carpi ulnar muscles and superficial flexor muscle. The median nerve innervated into the median surface of the brachial and metacarpal region, flexor carpi radial muscle, pronator teres muscles, superficial and profound digital flexor muscles. The general macroanatomical shape of the brachial plexus and the distribution of the nerves originating from this plexus displayed some differences from other birds.

The post hatching development of the female genital system in Indigenous Mallard Duck (Anas platyrhynchos)

The current research aimed at obtaining principal data on the morphological developmental changes that could occur during the post hatching periods in the female genital system of the Indigenous Mallard ducks and to conduct that twenty (immature and mature) ducks were used. Gross findings have revealed that the left ovary in 4 weeks sold ducklings appeared small triangular in shape, located at the dorsal part of coelom in contact caudally with the cranial division of the left kidney and cranially with left lung. In 8 and 12 weeks the left ovary has enlarged showed prominent granular surface. The left oviduct appeared as thin, translucent straighten tube with unapparent regions fixed by a thin doubled folds of oviductal ligament and ureter. In mature and laying ducks, the left ovary was large and irregular in shape, and showed numerous follicles of different developmental stages. The mature and laying left oviduct was fully developed into six well distinguished regions (infundibulum, magnum, isthmus, uterus, junction region and vagina). The present study has concluded that the first twelve weeks of post hatching periods had similar morphological features and showed inert genital organs which were not completely differentiated, while the age of twenty four weeks revealed completely differentiated female genital organs with sexual activity.

Proteomic analysis of liver development of lean Pekin duck (Anas platyrhynchos domestica)

The liver plays vital roles in digestion, metabolism and immune defense. To elucidate the molecular mechanism of nutrient metabolism and antioxidation of lean Pekin duck liver from hatching to slaughter, the proteome changes were investigated using 2-DE, MS, quantitative real-time PCR and bioinformatics. A total of 59 differentially expressed proteins were identified. Proteins involved in transportation were highly up-regulated in newborn ducks whereas 37 proteins associated with metabolism, defense and antioxidation were up-regulated in adult ducks. The over-expression of proteins at the last developmental stage presumably occurs to fulfill the needs of multiple functions of the liver. However, the over-expressed proteins related to transportation during the first developmental stage are involved in maintaining the high basal metabolism of newborn ducks. The functional enrichment analysis also confirmed these results. Furthermore, the protein interaction network predicted 28 proteins acting as key nodes for liver development. The validated expression between proteins and genes provides us target genes for future genetic analyses to improve the health and performance of these ducks. These significant advanced proteome data expand our knowledge on the physiology of the duck liver, thereby providing a potentially valuable foundation for molecular breeding to enhance feed efficiency and immunity and for optimizing the feeding strategy.

Production of donor-derived offspring after ovarian transplantation between Muscovy (Cairina moschata) and Pekin (Anas platyrhynchos) ducks

Transplantation of ovarian tissue between different breeds of chickens or Japanese quail can result in normal egg production and give rise to donor-derived offspring with a high frequency. The feasibility of interspecific ovarian transplantation was evaluated by transplanting ovarian tissue from Muscovy ducks to Pekin ducks just after hatch, with subsequent treatment of the recipients with an immunosuppressant. Among the 8 mature Pekin ducks that had received ovarian tissue from Muscovy ducklings, 2 produced fertile eggs when mated with Muscovy drakes, and one of these produced only Muscovy ducks, which were derived from the transplanted Muscovy ovary. The other produced mule ducks that were hybrids of the host Pekin duck and the Muscovy drake. Further development of interspecific transplantation of ovaries may provide a simple method for the conservation and propagation of endangered birds.

Factors affecting nest choice by Pekin ducks

To encourage nest use in breeder poultry flocks, it is important that nest boxes are attractive. Few studies have evaluated factors affecting nest attractiveness to ducks. We assessed the effects of nest box experience (Experiments 1 and 2) and features of nests, including degree of enclosure (Experiments 1 and 2) and the presence of an egg (Experiment 3), on nest site selection by sexually mature Pekin ducks. The hens were tested individually in pens containing different nest box choices. Nest preferences were determined based on the locations of 14 successively laid eggs. Ducks in Experiment 1 were provided with nest box access prior to the onset of lay (20 weeks of age, EXP group, N = 12) or at the time of preference testing (35 weeks of age, DELAYED-EXP group, N = 12). Delaying nest box access by 15 weeks did not significantly affect the proportion of eggs laid in nest boxes rather than on the floor ( P = 0.40). Regardless of experience ducks laid more than 66% of their eggs in nest boxes offering a higher degree of enclosure. Ducks in Experiment 2 were reared with either open-top (OP, N = 12) or closed-top (CL, N = 12) boxes. Regardless of rearing condition, ducks preferred boxes with the highest level of enclosure offered. Ducks laid twice the expected proportion (25%) of eggs in CL boxes with curtains ( P = 0.0004). CL boxes without curtains were used as predicted by chance, 25% ( P = 0.746), while OP boxes with ( P = 0.009) and without ( P = 0.015) curtains each contained only half the expected number of eggs. Ducks in Experiment 3 were provided with two nest boxes, one of which contained the egg laid the previous day. Each day, the newly laid egg was marked and either placed back in the nest box where it was found (HANDLED, N = 12) or moved into the adjacent nest box (MOVED, N = 12). Ducks in HANDLED and MOVED laid 97.6% and 79.8%, respectively, of their eggs in boxes containing the previous day's egg. While ducks in HANDLED were consistent in their choice throughout the test, those in MOVED developed the preference over time ( P = 0.039), suggesting that the preference for laying in a nest containing an egg may be influenced by experience. These results indicate that nest box enclosure and the presence of an egg are important in determining the nesting choices of Pekin ducks. Incorporating these features into nest boxes may be useful for increasing consistency of nest use in breeder duck flocks.

Ontogeny of testicular inhibin and activin in ducks: An immunocytochemical analysis

ABSTRACTThe ontogeny of testicular inhibin/activin in ducks was investigated. Testicular localization of three inhibin/activin subunits (α, βA and βB) was determined in embryonic and newly hatched ducks from 12 days of incubation to 1 day of age, in immature ducks and in adult ducks. In the duck embryonic testis, positive α‐subunit immunostaining was first detected in the Leydig cells and Sertoli cells on day 15 of incubation, whereas βA‐subunit and βB‐subunit immunostaining were found in Sertoli cells and primary germ cells on day 18 of incubation. In 1 month old ducks, intense staining of α‐subunit was present in the seminiferous epithelium consistent with localization in Sertoli cells and primary germ cells, and the immunostaining of the βA‐ and βB‐subunit was also present in Sertoli cells and primary germ cells. Specific immunostaining with inhibin/activin α‐, βA‐ and βB‐subunits antisera occurred in Sertoli cells in the adult duck testes. In conclusion, it was shown that, in the duck testis, the majority of α‐, βA‐ and βB‐subunits are colocalized in Sertoli cells with a certain degree of staining in germ cells and the α‐subunit is present in Leydig cells of embryonic testes before day 18 of incubation. These results indicate that Sertoli cells and possibly germ cells in the embryonic testes of late stage of incubation and newly hatched ducks, immature ducks and mature ducks may produce bioactive inhibin dimers, inhibin A and inhibin B, as a possible regulator of follicle‐stimulating hormone secretion. Free inhibin/activin subunits and their dimers may also play an autocrine/paracrine role in the development of the testis and spermatogenesis. Furthermore, early onset of the α‐subunit in duck testes indicates that it may have an autocrine/paracrine effect on steroid hormones, which is important for sex differentiation.

Food Habits of Lesser Scaup Aythya affinis Occupying Baitfish Aquaculture Facilities in Arkansas

AbstractLesser scaup Aythya affinis, medium‐sized black and white diving ducks, were collected at Arkansas baitfish farms during November‐December 1999 (N= 33), January‐February 2000 (N= 39), and March‐April 2000 (N = 22) to determine seasonal differences in their diet and their relative impact to baitfish production. The mass of gastrointestinal contents was used to determine the proportion of each diet item relative to all items recovered during stomach analyses. Chironomids were the primary food item recovered. Ten of 94 (10.6%) scaup contained identifiable fish biomass. Fish bones and otoliths were found in an additional 14 scaup (14.9%). All fish remains were identified (via otoliths) as those commonly produced at Arkansas baitfish farms (Cyprinidae). Other diet items (ranked by proportional mass) were vegetative seeds, snails, insects, crayfish, and other aquatic worms (class Oligochaeta). Scaup diets were similar among collection periods, between males and females, and between juvenile and mature ducks. We estimated the economic impact of lesser scaup to baitfish production based upon estimated duration of ducks at farms, the proportion of ducks containing fish, and scaup energetic requirements. Provided estimates of scaup abundance and the cost of bird harassment at a particular farm, economic thresholds (i.e., fish replacement cost as a function of scaup predation) will facilitate cost‐effective decisions regarding bird damage management at Arkansas baitfish aquaculture facilities.

Use of goose cells in haemagglutination tests with arthropod-borne viruses.

HAEMAGGLUTINATION studies with arthropod-borne viruses are normally carried out using red blood cells from one-day-old chicks, although cells from mature pigeons have been used in the case of Murray Valley encephalitis virus1. An observation made in the West African Council for Medical Research Laboratories in Lagos that cells from mature ducks were agglutinated by a yellow fever antigen led to a study of readily available domestic birds. Cells from Muscovy ducks (Cairina maschatai), from a local (Badagri) variety of the domestic duck (Anas boscas) and from Chinese geese (Cygnopsis cygnoides) were compared with cells from one-day-old chicks against yellow fever, Uganda S, Zika and West Nile antigens. Goose cells gave titres which were at least as high as those obtained with chick cells, and usually higher, and the settling patterns were consistently sharp and easy to read. Duck cells, although agglutinated, gave lower titres and showed a tendency to spontaneous agglutination in controls. Goose cells were thereafter used as a routine in the Lagos laboratory, and experience over more than a year has shown them to be highly satisfactory in haemagglutination and haemagglutination-inhibition tests with the antigens already mentioned, and in addition with antigens prepared against Semliki forest, Ilheus and the Trinidad 1751 strain of dengue virus. Details of this work will be published elsewhere.

The Value of Pasture in the Production of Goose Broilers

MODERN consumer preference together with the economy of production have been major factors in advancing sales of broiler and frier sized chickens and turkeys. For these reasons also, ducklings have gained in favor as compared with mature ducks. In each instance profitable production of these products is possible only under conditions which allow for rapid growth and early marketing.Synder and Orr (1953) reported that geese may be marketed with good consumer acceptance when from 8 to 14 weeks of age. Such goslings were found to have good fleshing and satisfactory finish. The highest percentage of total drawn weight occurred at 10 weeks of age and the highest percentage of total edible meat of the total drawn weight at 12 weeks of age, being superior in these respects to birds from the same groups slaughtered at 19 to 21 weeks of age.Recent interest in the commerical possibilities of goose …