The blood-brain barrier (BBB) is an important internal barrier. Herein, the electron microscope examination of duck BBB was performed during the brain development. Meanwhile, the genes/proteins of tight junctions (TJs) including zonula occludens-1, occludin, and claudin-5 in the duck brain were detected by Q-PCR and immunohistochemistry. The results showed the density of capillaries in the brain gradually increased during the embryonic period. The generation of the BBB and the specialization of its components occurred mainly in the embryonic stage. During this period, the endothelial cells (ECs) became thinner and pinocytic vesicles decreased; the TJs between EC membranes became longer and more electron-dense; the basement membrane surrounding ECs and pericytes gradually thickened; and the astrocyte foot processes appeared to wrap around the vessels. By the day of hatching (P1), the whole set of duck BBB structures was completely assembled and gradually improved in the subsequent growth process. Interestingly, compared with the cerebrum and cerebellum, the maturity level of the midbrain BBB was earlier seen during the embryonic stage. The expression of TJs increased during the embryonic period and remained stable by post-hatching. The study systematically investigated the histochemical and ultrastructural features of duck BBB during development and explored the corresponding relationship between structure and function.

Severe disease outbreaks of erysipelas in poultry flocks are caused by infection with the bacterium Erysipelothrix rhusiopathiae. This disease occurs in a wide range of poultry, including turkey, broiler chicken, hen, goose, and pheasant flocks. Erysipelas usually follows an acute course in birds, in the form of sepsis. Infections with E. rhusiopathiae occur through damaged skin or mucous membranes. The symptoms that occur just before death include unsteady locomotion and a lack of coordinated movement. A chronic form of bacterial infection primarily occurs in turkeys that have been vaccinated against erysipelas, and, in addition to affecting the joints, endocarditis can occur. Usually, carcasses are in good condition and correctly muscled, although ecchymosis might be visible in subcutaneous fat and thigh muscles, while internal organs become enlarged, such as the liver, spleen and kidneys. Histopathological tests indicate major vascular changes in the parenchymatous organs. Points of necrosis related to the infarctions of the large vessels are rarely observed, whereas spilled degenerative changes of parenchymatous organs are more likely to be observed. Turkeys are the only species of poultry for which vaccines against erysipelas have been registered; however, this vaccination is also effective for other poultry. E. rhusiopathiae is mainly sensitive to penicillin, but also responds to cephalosporins, tetracyclines, quinolines, clindamycin, erythromycin, and piperacillin.

The study pertains to phenotypic characterization of some breeds of duck (common white duck and Indian runner duck), Muscovy ducks (black and white feathered and sepia feathered) besides two breeds of geese (white and brown feathered and white feathered) reared in the state of West Bengal (India). The study was conducted at five locations of the state and comprised 1395 ducks and 600 geese. The data were analysed statistically using mainly descriptive statistics, the differences in mean were analysed using Duncan's multiple range test. Both qualitative and quantitative traits were considered in the study. The qualitative traits were shank colour, bill colour, colour of the feathers, skin colour, egg shell colour, the presence or absence of beans, body carriage, bill type and colour of the eyes, while the quantitative traits included in the study were weight of the ducks and weight of the eggs. Some production traits such as numbers of eggs laid per year and dressing percentage of the drakes and ganders of each breed too have been studied. The ducks and geese are raised under semi-intensive management system and mostly depend on scavenging for their nutritional needs. This results in poor egg production and at times loss of stock because of diseases. The study regarding average egg production indicated that the Muscovy ducks and the geese have poor egg production, whereas the Indian runner followed by the common white duck are potentially the best. The ducks are important source of earnings for the small holder farmers and are raised both for meat and eggs, while the geese are reared mostly for ornamental purpose. However, the populations of the ducks are fast dwindling because of avian influenza in the region and because restocking is mostly being carried out with less adapted Khaki Campbell ducks. This happens mainly because the government farms that were responsible for providing the ducklings for restocking maintain Khaki Campbell ducks and do not have the parental stock of the native duck breeds, while restocking of the Muscovy ducks and geese are carried out by the rearers themselves. There are also no prevailing breeding programmes to conserve, select, maintain and distribute the native breeds of duck and geese. Hence, it is of earnest importance to conserve the avian genetic resources before the population dwindles further.

In 2008, avian bornaviruses (ABV) were identified as the cause of proventricular dilatation disease (PDD). PDD is a significant condition of captive parrots first identified in the late 1970s. ABV infection has subsequently been shown to be widespread in wild waterfowl across the United States and Canada where the virus infects 10–20% of some populations of ducks, geese and swans. In most cases birds appear to be healthy and unaffected by the presence of the virus; however, infection can also result in severe non-suppurative encephalitis and lesions similar to those seen in parrots with PDD. ABVs are genetically diverse with seven identified genotypes in parrots and one in canaries. A unique goose genotype (ABV-CG) predominates in waterfowl in Canada and the northern United States. ABV appears to be endemic in North American waterfowl, in comparison to what appears to be an emerging disease in parrots. It is not known whether ABV can spread between waterfowl and parrots. The discovery of ABV infection in North American waterfowl suggests that European waterfowl should be evaluated for the presence of ABV, and also as a possible reservoir species for Borna disease virus (BDV), a related neurotropic virus affecting horses and sheep in central Europe. Although investigations have suggested that BDV is likely derived from a wildlife reservoir, for which the shrew and water vole are currently prime candidates, we suggest that the existence of other mammalian and avian reservoirs should not be discounted.

The aim of this study was to analyse the effects of species (Muscovy and Pekin ducks) and age at the beginning of the overfeeding period on fatty liver production, carcass composition and lipid and moisture content of the liver and breast muscle. We reared four groups of 40 ducks per species for the study, starting at 2-week intervals in order to have four different ages together at the beginning of the overfeeding period (10, 12, 14 and 16 weeks). At the end of the overfeeding period, all ducks were slaughtered. Our results confirmed the high levels of difference in carcass composition and lipid content in the plasma, liver and breast muscle between Muscovy and Pekin ducks at all ages. Pekin ducks were not able to develop a high degree of hepatic steatosis, but had increased lipid storage in peripheral adipose and muscle tissues than Muscovy ducks. However, the fatty liver weight of Pekin ducks increased with age, with lipid deposition in the liver and peripheral tissues. The ability of Muscovy ducks to produce fatty livers remained unchanged with age in line, with lipid deposition in the liver and peripheral tissues. The sites of lipid deposition thus depend on species and not on the physiological maturity of ducks.

The potential for direct transmission of type A influenza viruses from wild waterfowl to humans is undefined. This study estimated exposure of hunters to avian influenza virus (AIV) resulting from direct contact with potentially infected waterfowl in Georgia (GA), Louisiana (LA) and Minnesota (MN), and demonstrated variation in the risk of exposure to AIV by hunting location and time. Hunting begins earlier in MN, starting in October, and later in GA and LA, usually starting in November. In addition, the numbers of hunters and birds harvested varies considerably in each state, with LA hosting the largest harvest in the USA Temporal effects resulted in variation of the exposure risk per hunter-day, with a higher risk associated with the earlier months of the hunting season. Exposure risk in locations varied due to AIV prevalence during each hunting season, average bird harvest per hunter-day, and ratio of juveniles/adult birds harvested (higher risk associated with higher ratios). Population risk is discussed based on the exposure risk and number of active hunters in each state per month. The risk of human exposure to AIV was also shown to be temporally distinct from the time of greatest risk of human influenza A infection during circulation of seasonal human influenza viruses, making recombination events due to co-infection unlikely.

Waterfowl production has been on an upward trend and has become increasingly important around the world over time. The production of ducks worldwide in 2010 was 6-fold greater that of 1961, and that of geese was 9.8-fold over the same period. The progress in waterfowl production represents not only an increase in the quantity of the product, but also in quality. Waterfowl performance progress, genetics and breeding, reproduction, nutrition, management and housing, and product quality and utilisation are discussed in this article, alongside a review of the history of the Waterfowl Working Group (WWG) which was established in 1969 as Working Group 8 under the European Federation (EF). After moving to the Asian Pacific Federation (APF) in 2011, it became Working Group 2.

The development of Trichobilharzia australis Blair & Islam, 1983 in the intermediate host, Lymnaea lessoni Deshayes and in experimental definitive hosts, Muscovy ducks is described, 24 hours after entry into the snail, miracidia had lost their cilia, epidermal plates and lateral processes and became young mother sporocysts. They were located in the tissues of the head-foot organ of the snail and were oval in cross section but still retained the shape of a miracidium, and measured 0·058–0·66 × 0·041–0·049 mm. From the seventh day onward young mother sporocyts were tubular, thin-walled, irregular in shape and were in the tissues of the lung and kidney of the snail. On the 24th day mature mother sporocysts and young daughter sporocysts were found in the digestive gland. Between the 24 th and 29th day mature daughter sporocysts with fully developed cercariae ready to emerge, or already emerged, could be seen in the digestive gland of the snail. Cercariae emerged from the snail from the 29th to 46th day after exposure at 25°±1°:C. The prepatent period of T. australis in the Muscovy ducks was 22 to 42 days after the beginning of exposure to cercariae.

Mule duck, a cross between a Muscovy drake and a Pekin female, is reported by the farmers to frequently express fear behaviours, such as man avoidance. The genetic basis of fear responses in mule ducks was therefore investigated in this study. According to a previous experiment, the dominant effect of Pekin genotype was hypothesised; however, due to the absence of birds from the reciprocal cross, a superiority of the Pekin in additive effect could not be distinguished from a direct maternal additive effect. In order to clarify this, ducks from the mule genotype, the two parental genotypes (Pekin and Muscovy) and the reciprocal intercross (hinny) underwent a set of physiological and individual behavioural tests of fear. Both parental genotypes were highly fearful but exhibited responses of different patterns: Pekin ducks manifested a higher locomotor activity, whereas the Muscovy ducks showed a higher avoidance to man. Hybrids expressed higher panic responses and specific fear of man than the two parent breeds. Both hybrids expressed similar patterns and the maternal effects were not significant. Significant heterosis effects were found for most of the behavioural responses, in agreement with the fact that higher fear responses were expressed by the hybrids compared to the parental genotypes. A significant heterosis effect was also found for basal adrenal activity; hybrids having higher basal level than parental genotypes. Maximum capacity of adrenal response appeared to be determined by direct additive effects with a superiority of the Pekin genotype.

As a major natural reservoir of influenza virus and an important food source, the duck is of great biological interest, e.g. in the area of host-pathogen interactions. Recently, preliminary genetic and cytogenetic maps of the duck have become available, providing for the first time a glimpse at a comparative map between the duck and chicken. These genetic tools have been used to detect QTLs related to duck growth, carcass and meat quality traits. However, molecular genetic research in the duck is only in its infancy. In the future we can expect the development of new duck resources, including a high-density genetic map, detailed comparative maps with the chicken and other vertebrates - and given the pace of genomics, possibly a genome sequence. These new resources will be used to evaluate the genetic diversity of global duck breeds, to define genetic markers to increase the quantity and quality of egg and meat products, and to aid in the battle against infectious diseases, such as avian influenza.

The susceptibility to develop hepatic steatosis is known to differ between duck species, especially between Muscovy and Pekin ducks. This difference could be explained by either differential responses of species to overfeeding or genetic differences in hepatic lipid metabolism. The aim of the present study was to compare the intensities of the different hepatic pathways (oxidation, lipogenesis, esterification, secretion, etc.) of the two main nutrients (glucose and linoleic acid (LA)) reaching the liver of ad libitum-fed Muscovy (n 6) and Pekin (n 6) ducks using the ex vivo method of liver slices incubated for 16 h with [U-14C]glucose, [1-14C]LA and [35S]methionine added to the survival medium. In such experimental conditions, the lipogenesis pathway from glucose was 2-fold higher (P < 0·05) in the liver of the Muscovy duck than in that of the Pekin duck. Furthermore, the hepatic uptake of LA was 2-fold higher (P < 0·05) in the Muscovy duck than in the Pekin duck leading to a 2-fold higher (P < 0·05) esterification of this fatty acid in the liver of the Muscovy duck. The hepatic secretion of VLDL was higher (P < 0·01) in the Muscovy duck than in the Pekin duck but insufficient to prevent lipid accumulation in the liver of the Muscovy duck. In conclusion, these results show the influence of the species on the hepatic metabolism of ducks in relation to their susceptibility to develop fatty liver. These results should shed light on the metabolic regulations that might underlie susceptibility to hepatic steatosis in the the human liver.

Duck breeding in France is directed mainly towards ‘foie gras’ (duck fatty liver) production. Nowadays the roasted duck, produced from the pure Muscovy, is economically a less important industry. About 95% of foie gras production comes from force-fed mule duck, the remaining 5% being from the Muscovy duck. After an overview of the French economical and technical context of this production, the paper will focus on the genetic aspects of the mule duck, at the level of theoretical knowledge and considering practical applications for selection. As the mule duck is an infertile hybrid between a female common duck (Anas Platyrhynchos) and a Muscovy drake (Cairina moschata), selection approaches are carried out on both parental strains. But to implement selection, genetic parameters (heritability and genetic correlations) and cross-breeding parameters (direct and maternal additive genetic effects, heterosis effect) need to be known. Our review covers both the reproductive mule parental traits, either in pure strain or in cross-breeding, with main results on the dam side for laying, fertility and hatchability and also considers the mule productive traits, such as growth, feather colour, behaviour, feed efficiency, body composition, force-feeding ability and products quality. Genetic variability of mule duck traits can be established from estimates on either the dam's side, on the sire's side, or on both sides simultaneously. This review represents a comparison of fatty duck selection, which is operated by three major private French companies, with outlines of the breeding scheme specificity.

A conservation scheme for local poultry breeds from the Veneto region (Italy), the Co.Va. (Conservazione e Valorizzazione di Razze Avicole Locali Venete - Conservation and valorisation of local poultry genetic resources of Veneto region) project began in 2000 with finance provided by the Veneto Region. This project involved four organic farms located in different areas (mountain, hill and plain) in the region. The local chicken breeds included in the project were the Robusta Maculata, Robusta Lionata, Ermellinata di Rovigo, Pépoi and Padovana; the local duck breeds were the Germana Veneta and Mignon; the local turkey breeds were the Bronzato Comune and Ermellinato di Rovigo; and the local guinea fowl breed was the Camosciata. All breeds are dual-purpose breeds and are utilized for meat and egg production. The Department of Animal Science of the University of Padova planned a marker-assisted conservation scheme based on the maintenance and multiplication of these breeds within their production system (in situ conservation scheme). The objectives of the farmers involved in this project were to use these genotypes to generate typical regional products for local markets, to support the development of economically marginal areas through the revaluation of local breeds and to allow the preservation of animal biodiversity.

Comparison of the efficiencies of meat production between chickens, turkeys and ducks at 7 weeks of age indicates that although the turkey broiler is most efficient in feed utilization, the high cost of poult production neutralizes this advantage. Thus, chicken broiler edible meat is cheaper to produce by =16 and 25% than meat from turkeys and ducks, respectively. The favourable feed utilization of the turkey broiler is partly due to the concave growth curve (with reduced feed consumption for maintenance) and primarily due to the markedly lower body fat concentration, which in turkeys is about six to ten times lower than in chickens and ducks, respectively. The low body fat level of turkey, together with the lowest cost of edible meat protein, may appeal to consumers who wish to reduce the amount of animal fat in their diets. This advantage of low fat concentration in the turkey broiler is sharply reduced at 16–24 weeks of age. There is therefore justification to examine the possibility of marketing oven-ready turkey broilers, or at least female turkey broilers, at 7–10 weeks of age.