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The aim of the study was to compare the bodyweight and body measurements, carcass composition, and characteristics of major visceral organs in male and female Pekin ducks. A total of 80 hybrid SM3 Heavy ducks were kept in a conventional building and fed complete commercial diets ad libitum. The male and female were weighed individually at one day old and their bodyweight and body measurements were determined at 21, 35 and 49 days of rearing. On day 49, 20 males and 20 females were chosen for slaughter. After slaughter, the carcasses and visceral organs were collected. No significant differences were observed between males and females in bodyweight (1 d, 58.6 vs 56.3 g to 49 d, 3518 vs 3433 g) and feed conversion ratio (FCR) (0–49 d, 2.44 vs 2.49 kg/kg gain). At 35 days old males demonstrated a significantly longer body and shanks and, at 49 days old a significantly longer body than females. The sex of ducks had no significant effect on the percentage of wings, muscles from breast and legs, skin with subcutaneous fat, abdominal fat and carcass remainder. The neck content was significantly greater in male carcasses than female ones. The contents of proventriculus, liver, and spleen in the bodies of males and females were similar. Gizzard percentage was significantly greater in males, and heart percentage was significantly greater in females. Due to their high bodyweight, good FCR, and favourable carcass composition, SM3 Heavy male ducks are more useful as broiler duck than females.Keywords: carcasses, digestive system, growth, Pekin duck, sex

Lean-type Pekin duck is a breed gained through long-term selection and great effort has been exerted to understand the mechanisms underlying increased muscle yields. However, the genes involved in Pekin duck embryonic breast muscle development have not been explored to date. In this study, we investigated gene expression profiles in Pekin Duck embryonic breast muscle at hatched day 13 (E13), E19, and E27 using RNA-seq. In total, we produced 519,312,178 raw reads resulting in 497,348,158 high-quality reads after filtering. The mapping, distribution of reads along annotated genes, and consistency across replicates demonstrates the high quality of the RNA-seq data used in this study, allowing us to continue with the downstream analysis. Significantly fewer differentially expressed genes (DEGs) were identified between E13 and E19 (203 DEGs) compared to E27 and E19 (2,797 DEGs). Many DEGs highly expressed in E19 are involved in metabolic processes and cell division. KEGG analysis showed many pathways associated with fat development were significantly enriched for DEGs highly expressed in E27. These results provide a basis for the further investigation of the mechanisms involved in Pekin duck embryonic breast muscle development.

Bu araştırmada, Uludağ Üniversitesi Ziraat Fakültesi Tarımsal Uygulama ve Araştırma Çiftliğinde yetiştirilen, 161 adet Pekin ördeğinden 5-10 ml kan örneği alınmıştır. Bu örneklerde PRL geni polimorfizmi, PCR-RFLP yöntemi kullanılarak incelenmiştir. PRL geni 1. intron ve 5. ekzon alanlarındaki tek nükleotid polimorfizmini (SNP, single nukleotid polymorphism) bulmak için sırasıyla Xba1 ve Pst1 restriksiyon enzimleri ve iki adet primer çifti kullanılmıştır. Sadece 1. intron bölgesinde polimorfizm gözlenmiştir. 1. intronda üç genotip (TT, TG ve GG) gözlenirken, 5. ekzonda tek genotip gözlenmiştir. 1. introndaki T ve G alleli gen frekansları sırasıyla 0,5062 ve 0,4938 olarak bulunmuştur. TT, TG ve GG genotiplerinin frekansları ise sırasıyla 0,28, 0,45 ve 0,27 olarak hesaplanmıştır. Bu araştırmada üzerinde çalışılan populasyon HW (Hardy Weinberg) dengesinde olduğu gözlenmiştir. In this study, 5-10 ml blood samples were obtained from 161 Pekin ducks raised in Uludağ University Agricultural Practice and Research Farm. In these cases, PRL gene polymorphism was investigated using the PCR-RFLP method. Xba1 and Pst1 restriction enzymes and two primer pairs were used to find the single nucleotide polymorphism (SNP) in the PRL gene intron 1 and exon 5 sites, respectively. Only intron 1 site polymorphism was observed. Three genotypes (TT, TG and GG) were observed in intron 1 site while only one genotype was observed in exon 5 site. T and G allele gene frequencies in intron 1 were found as 0,5062 and 0,4938 respectively. The frequencies of TT, TG and GG genotypes were calculated as 0.28, 0.45 and 0.27, respectively. The population studied in this study was observed to be in the HW (Hardy Weinberg) equilibrium. Tebliğ İnşaat Emlak San. Ve Tic. Ltd. Şti

Interferons (IFNs) are the first line of defense against viral infections in vertebrates. Type III interferon (IFN-λ) is recognized for its key role in innate immunity of tissues of epithelial origin. Here we describe the identification of the Pekin duck IFN-λ ortholog (duIFN-λ). The predicted duIFN-λ protein has an amino acid identity of 63%, 38%, 37% and 33% with chicken IFN-λ and human IFN-λ3, IFN-λ2 and IFN-λ1, respectively. The duck genome contains a single IFN-λ gene that is comprised of five exons and four introns. Recombinant duIFN-λ up-regulated OASL and Mx-1 mRNA in primary duck hepatocytes. Our observations suggest evolutionary conservation of genomic organization and structural features implicated in receptor binding and antiviral activity. The identification and expression of duIFN-λ will facilitate further study of the role of type III IFN in antiviral defense and inflammatory responses of the Pekin duck, a non-mammalian vertebrate and pathogen host with relevance for human and animal health.

An experiment was designed to contain eight feed consumption levels (ad libitum, 300, 330, 360, 390, 420, 450, 480 g/day/bird) to evaluate the effects of feed consumption levels on growth performance and apparent digestibility of nutrients for White Pekin ducks from 35 days to 42 days of age. Ninety-six 35-day-old male Pekin ducks were randomly assigned into eight treatments, each containing six replicate pens with two birds per pen. All birds of the treatment group 1 as the control group was fed ad libitum and the birds of the treatment groups from 2 to 8 were quantitatively fed by force-feeding. The feed intake was 300, 330, 360, 390, 420, 450, 480 g/day/bird for treatment groups 2 through 8, respectively. Results of growth performance showed that feed consumption levels affected final body weight and average daily gain significantly (P 0.05). Based on the broken-line regression model analysis with body weight gain data, the optimum feed consumption level for Pekin ducks w...

Rising temperatures are severely affecting the mortality, laying performance, and meat quality of duck. Our aim was to investigate the effect of acute heat stress on the expression of heat shock proteins (HSPs: HSP90, 70, 60, 40, and 10) and inflammatory factors (nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2)) and antioxidant enzyme activity (superoxide dismutase (SOD), malondialdehybe (MDA), catalase (CAT), total antioxidant capacity (T-AOC)) in livers of ducks and to compare the thermal tolerance of Pekin and Muscovy ducks exposed to acute heat stress. Ducks were exposed to heat at 39 ± 0.5 °C for 1 h and then returned to 20 °C for 1 h followed by a 3-h recovery period. The liver and other tissues were collected from each individual for analysis. The mRNA levels of HSPs (70, 60, and 40) increased in both species, except for HSP10, which was upregulated in Muscovy ducks and had no difference in Pekin ducks after heat stress. Simultaneously, the mRNA level of HSP90 decreased in the stress group in both species. Morphological analysis indicated that heat stress induced tissue injury in both species, and the liver of Pekin ducks was severely damaged. The activities of several antioxidant enzymes increased in Muscovy duck liver, but decreased in Pekin duck. The mRNA levels of inflammatory factors were increased after heat stress in both duck species. These results suggested that heat stress could influence HSPs, inflammatory factors expression, and the activities of antioxidant enzymes. Moreover, the differential response to heat stress indicated that the Muscovy duck has a better thermal tolerance than does the Pekin duck.

WOS: 000334045600027, PubMed: 24570471, The current study was carried out to investigate the effects of breeder age on egg composition, changes of embryo, yolk sac, and yolk minerals during incubation and hatchability in Pekin ducks. A total of 495 freshly laid eggs were obtained from the same flock of Pekin ducks, aged 28, 34, and 40 wk, and were reared in accordance with the management guide of the duck breeders (Star 53-Grimaud Freres). At each breeder age, egg measurements were made on a random subsample of unincubated eggs. Embryo and yolk sac measurements were made on embryonic day (E) 12, E16, E20, and E25. On d 28 of incubation, the healthy ducklings were removed and sex of chicks was determined. All chicks were weighed and hatching results were determined. Egg weight and yolk percentages increased; however, albumen percentages, shell thickness, and yolk index decreased as the flock aged. Shell percentages, shell breaking strength, albumen index, and haugh units were not affected by breeder age. Also, breeder age affected the Mg, P, K, Ca, Cu, and Zn levels in the yolk, except for Na level on day of setting, and breeder age affected the mineral consumed by embryo during incubation. However, on E25, the levels of examined minerals, except for P level in the yolk sac, were not statistically different in duck breeder age groups. Relative yolk sac and embryo weights of eggs obtained from different breeder ages varied from E16 to E25; however, embryo length was different in breeder age groups from E12 to E20. Hatching weight was affected by breeder age and sex. Hatching results were not different among breeder age groups. This study indicates that breeder age is important for some egg characteristics, relative yolk sac weight, some contents of minerals in the yolk, embryonic growth during incubation, and duckling weight.

Fatigued walking condition (FWC) in ducks is an important welfare and processing issue during the loading/unloading to the processing plant that can be related to heart and bone development. An experiment was conducted to evaluate the effects of incubation conditions on duck embryo bone and heart development and their subsequent effects on ducks showing FWC at market age. Four groups of 2500 Pekin duck eggs were subjected to combinations of two incubation temperature profiles (elevated [E] and normal [N]) and two eggshell conductance profiles (G) (reduced [GR] and normal [GN]). At hatch 10 ducklings from each treatment combination were sampled for heart, liver, residual yolk, and total body weight as well as relative weights (organ percentage of whole body weight). Femur, tibia, and tarsus length and weight were also obtained, and relative asymmetry (RA) was calculated for each leg section. At 35 days of age during unloading of the truck at the slaughter plant, five hens and five drakes demonstrating normal walking and FWC were sampled. Body, heart, and ventricular weights were obtained along with femur, tibia and tarsus length, weight, and RA. Bone strength was evaluated using a three-point bending test, and tibia ash content was assessed. At hatch duckling bone characteristics and organ weights were found to be primarily affected by GR conditions, while heart development in older ducks was mainly impacted by E incubation temperatures. Tibia and relative weight at 35 days were also increased by GR and E. Fatigued ducks presented heavier tibias with more RA and cortical thickness but lower ash percentage. In conclusion, the changes in bone development during incubation and posthatch life were related to duck FWC presence during transportation to the processing plant.

Aflatoxin contamination in feed and feed ingredients is of high worldwide prevalence, posing serious risks to the livestock industry. A series of studies were conducted to better understand the comprehensive impact of aflatoxicosis and its interrelationships with dietary modifications in broiler chicks and ducks. Results of these studies emphasize the many factors that the severity of aflatoxicosis depends on, including animal species, age, presence of mycotoxin adsorbent, and concentration of major dietary nutrients. Exposure to 2 mg/kg cultured AFB1 led to reduced feed intake, BW gain, depressed feed efficiency, increased relative liver weight, negatively affected serum measures and complement activity, as well as affected hepatic gene expression in 21 d broiler chicks. Additionally, impaired gut barrier, increased endogenous N loss, and reduced energy, N, and amino acid digestibility, and altered mRNA expression of intestinal tight junction proteins and transporters are also consequences of AFB1 exposure at 1.5 mg/kg in broilers. Disparately, as low as 0.1 mg/kg AFB1 led to significantly impaired growth, liver functions, and innate immune dynamics in 14 d Pekin ducklings, while effects of AFB1 on the gastrointestinal tract are less noticeable in ducks, with partial changes in jejunum morphology, digestive enzyme activity, and apparent energy digestibility. This suggests that while broilers may be more resistant, ducks are extremely sensitive to AFB1, and that the negative effects from AFB1 primarily result from reduced feed intake for ducks. Although total protection was not observed, supplementing HSCAS at 0.05% was effective to partially prevent aflatoxicosis in both broilers and ducks, as shown by improved performance (weekly but not cumulative in both species), restoring the negatively affected serum measures, and increased relative liver weight. Whether this is a direct effect on the liver and/or indirect result from reduced AFB1 absorption awaits further verification. Notably, the tested HSCAS was able to increase the mRNA expression and protein activity of major hepatic anti-oxidant activity, suggesting stimulated anti-oxidant function of the animal and likely a better ability to relieve the oxidative stress during aflatoxicosis. Thus, this may be a direct cause for the relieved liver damage by HSCAS. In addition to non-nutritive adsorbents, dietary nutrients can also influence the response and extent of the animal’s response to AFB1 exposure. A significant interaction of dietary crude protein and AFB1 was found in broilers, where the growth performance and health impairment (including serum measures, gut permeability, and N and amino acid digestibility) from aflatoxicosis were augmented when birds were fed a lower CP diet, and were completely eliminated by a higher CP diet. Higher dietary protein also improved BW gain and G:F ratio in ducks during aflatoxicosis, but no interaction was observed. Nevertheless, in both species, feeding low protein diets exacerbated the negative effects of AFB1, thus extra caution is needed when low CP diets are being fed. In addition, higher dietary branched chain amino acids (BCAA), key regulators in protein synthesis, improved all performance measures in broilers during aflatoxicosis, but no interaction was observed and higher BCAA negatively affected nutrient digestibility and serum measures. These observations reveal the complexity of the dynamic relationship between aflatoxicosis and dietary nutrients. On the other hand, the question remains whether in vitro response can be used to predict in vivo toxicity with sufficient accuracy. Good in vitro estimation of the toxicity potential of sample may be useful in initial screening of feed and feed ingredients. By exploring the response of fresh primary duck embryonic fibroblasts to various cytotoxins and mycotoxins, we showed that primary DEF had a higher sensitivity to toxins compared to HepG2 cells, and thus great potential in serving as a cytotoxicity screening model in vitro. Further attention should be given to the understanding of additive, synergistic, and antagonistic effects of multiple mycotoxins in in vitro systems and implications for animal responses in vivo.

Gaseous exchange is very important for embryonic development during the incubation of bird eggs. The present study was carried out to investigate the effect of carbon dioxide (CO2) pumping during the first 10 days of Pekin duck egg incubation on hatching characteristics, embryonic growth, hormonal concentrations and the post-hatch weight of the ducks. Two different ventilation conditions were used in this study. In one condition (V), the incubator was ventilated standard. In the other condition (NV), CO2 was gradually pumped into a non-ventilated incubator to reach and maintain a 1% concentration through the first 10 days of incubation, after which the incubator was ventilated for the rest of the incubation period. The CO2 percentage in the V incubator was constant at approximately 0.18%; by contrast, in the NV incubator, the concentration was increased gradually from 0.17% to 1%, where it was maintained through the 10th day of incubation. Throughout the incubation period, the egg weight loss and the embryonic mortality percentages were significantly lower in NV than in V. The hatchability of fertile eggs and the weights of ducklings at hatch were significantly higher in NV than in V. The embryonic T3, T4 and corticosterone levels in NV were significantly higher than those in V. Additionally, the haematological parameters (haemoglobin, packed cell volume and red blood cells) of the embryos were significantly higher in NV than in V. Furthermore, a total of 1198 ducklings for the V and NV conditions, all one day old, were individually weighed and then transferred into randomly assigned floor pens with 3 replicates for each ventilation condition. The feed conversion ratio of the ducks was significantly lower in NV than in V, while the reverse was true of body weight at different ages. Therefore, we can conclude that the NV condition with circulation of CO2 for the first 10 days of incubation is preferable to the V condition.

Enterococcus cecorum (EC) was thus far only known as a pathogen for broilers and broiler breeders. Recently there was evidence of EC field outbreaks in Pekin duck flocks in Germany. In this study we experimentally reproduced an EC infection in Pekin ducks. At 12 days post hatch, groups of Pekin ducks were infected orally, via the thoracic air sac or intravenously with 1.5 × 10(9) colony-forming units (CFU) of EC per bird or via the air sac with 8.5 × 10(5) or 8.5 × 10(7) CFU per bird. Ducks of the intravenously infected group showed 100% mortality after 2 days post infection. The air sac inoculated high-dose group exhibited a mortality rate of 67%. Birds that were infected with 8.5 × 10(5) and 8.5 × 10(7) CFU showed 6.7% mortality after 7 days post infection. Dead birds displayed pneumonia, airsacculitis, pericarditis and splenitis and EC was re-isolated from these organs. Surviving birds of all groups apart from the orally infected ducks demonstrated clinical signs such as huddling, reduced mobility and diarrhoea. Furthermore, they showed gross pathological lesions including airsacculitis and splenitis and lower bodyweights than the control group at necropsy on days 7, 14 and 21 post infection. The present study clearly confirms that EC is pathogenic for Pekin ducks after experimental infection via the intravenous route or the respiratory tract. EC therefore has to be considered as an emerging avian pathogen not only in broilers but also in Pekin ducks.

The most recent pandemic clade of highly pathogenic avian influenza (HPAI) H5, clade 2.3.4.4, spread widely, with the involvement of wild birds, most importantly wild waterfowl, carrying the virus (even asymptomatically) from Asia to North America, Europe, and Africa. Domestic waterfowl being in regular contact with wild birds played a significant role in the H5Nx epizootics. Therefore, protection of domestic waterfowl from H5Nx avian influenza infection would likely cut the transmission chain of these viruses and greatly enhance efforts to control and prevent disease outbreak in other poultry and animal species, as well as infection of humans. The expectation for such a vaccine is not only to provide clinical protection, but also to control challenge virus transmission efficiently and ensure that the ability to differentiate infected from vaccinated animals is retained. A water-in-oil emulsion virus-like particle vaccine, containing homologous hemagglutinin antigen to the current European H5N8 field strains, has been developed to meet these requirements. The vaccine was tested in commercial Pekin and mule ducks by vaccinating them either once, at 3 wk of age, or twice (at 1 day and at 3 wk of age). Challenge was performed at 6 wk of age with a Hungarian HPAIV H5N8 isolate (2.3.4.4 Group B). Efficacy of vaccination was evaluated on the basis of clinical signs, amount of virus shedding, and transmission. Vaccination resulted in complete clinical protection and prevention of challenge virus transmission from the directly challenged vaccinated ducks to the vaccinated contact animals.Una vacuna basada en partículas similares a virus proporciona un alto nivel de protección contra el desafío con un virus homólogo de influenza aviar de alta patogenicidad H5N8 en patos mula y Pekin, incluida la prevención de la transmisión. El clado pandémico más reciente de influenza aviar altamente patógena H5, clado 2.3.4.4, se diseminó ampliamente, con la participación de aves silvestres, siendo las aves acuáticas más importantes, portando el virus (incluso asintomáticamente) de Asia a América del Norte, Europa, y África. Las aves acuáticas domésticas en contacto regular con aves silvestres desempeñaron un papel importante en las epizootias H5Nx. Por lo tanto, la protección de las aves acuáticas domésticas contra la infección por influenza aviar H5Nx probablemente cortaría la cadena de transmisión de estos virus y aumentaría en gran medida los esfuerzos para controlar y prevenir brotes de enfermedades en otras aves comerciales y especies animales, así como la infección en humanos. La expectativa de una vacuna de este tipo es no solo brindar protección clínica, sino también controlar la transmisión del virus de desafío de manera eficiente y garantizar que se mantenga la capacidad de diferenciar a los animales vacunados. Se ha desarrollado una vacuna emulsionada en aceite con partículas similares al virus, que contiene el antígeno de hemaglutinina homóloga a las cepas de campo H5N8 europeas actuales, para cumplir con estos requisitos. La vacuna se probó en patos de Pekín y mulas comerciales, vacunándolos una vez, a las tres semanas de edad, o dos veces (al primer día y a las tres semanas de edad). El desafío se realizó a las seis semanas de edad con un aislado de alta patogenicidad H5N8 húngaro (2.3.4.4 Grupo B). La eficacia de la vacunación se evaluó en función de los signos clínicos, la eliminación viral y la transmisión. La vacunación dio como resultado una protección clínica completa y la prevención de la transmisión del virus de desafío de los patos vacunados.

Five hundred ten duck eggs of Pekin and each of Muscovy duck eggs were incubated to determine fertility and hatchability. The eggs were cleaned and stored at 18-21oC for 6 days prior to setting in the incubator. The eggs were incubated in a forced-draft electric incubator and the hatching performances were recorded. Ninety Pekin and ninety Muscovy day-old ducklings were randomly selected from the hatched ducklings for a growth trial. Each breed was divided into three replications and each replication had 30 ducklings. They were reared up to 10 weeks of age. Fertility of Muscovy duck eggs tended to be higher (P>0.05) than that of Pekin duck eggs. Hatchability of Pekin egg on fertile egg was higher (P0.05) in Muscovy ducklings than that of Pekin. At 10 weeks of age, Muscovy ducklings were slightly heavier (P>0.05) than that of Pekin. It was concluded that the fertility of Pekin and Muscovy ducks are more or less similar while hatchability is higher in Pekin ducks. Muscovy ducks are superior in respect of feed conversion and growth rate.DOI: http://dx.doi.org/10.3329/pa.v20i1-2.16859 Progress. Agric. 20(1 & 2): 93 – 98, 2009

Flavin-containing monooxygenase 3 (FMO3) is an important monooxygenase for catalytic oxygenation of many harmful xenobiotics. Mutations in the FMO3 gene have been identified as causing trimethylaminuria in human and fishy off-flavor in cow milk and chicken eggs. In this study, the full-length cDNA sequence of Pekin duck FMO3 gene was cloned, sequenced, and characterized. The full-length cDNA sequence consisted of 1,846 bp and contained a 1,599 bp open-reading frame encoding 532 amino acids. Duck FMO3 gene shared a similar nine exon-eight intron structure with chicken and human. The duck FMO3 putative protein sequence showed high identity with that of chicken (82 %), and relative low identity with those of mammals (61-66 %). We also found that the duck FMO3 gene was dramatically expressed in liver, lung, and kidney compared to that in other tissues in the ducks, indicating the possible roles the FMO3 gene could play in the three tissues. By bidirectional sequencing, we also found one nonsense mutation, 5 nonsynonymous, and 21 synonymous mutations in the coding region of the FMO3 gene in 11 duck breeds and some of them were predicted to be potentially associated with the activities of FMO3 protein.

Previous research has shown that providing light during incubation can have positive effects on hatchability and chick quality; however, white light alone has been observed to improve these factors only in pigmented broiler eggs and non-pigmented white layer eggs. Monochromatic red light has been shown to improve hatchability in layer eggs. Therefore the objective of this study was to utilize one light fixture that emitted both white and monochromatic red light to determine if this one light source could improve hatchability in both types of chicken eggs and pigmented Pekin duck egg. To determine this, 3 experiments were conducted, the first using White Leghorn eggs (N = 6912), the second using commercial broiler eggs (N = 4608), and the third using commercial Pekin duck eggs (N = 3564) in which eggs were incubated with 12 h of light and 12 h of darkness (LED) or complete darkness (DARK); the light level was 250 lux. Hatchability, embryo mortality, and hatchling quality were measured. In Experiment 1, LED had fewer early dead embryos (P = 0.03), less overall embryo mortality (P = 0.05), fewer chicks with unhealed navels (P0.001), fewer chicks with defects (P0.001), and a higher percentage of fertile eggs that hatched (P = 0.05) than DARK. In Experiment 2, LED had fewer chicks with unhealed navels (P = 0.003), fewer chicks with defects (P = 0.001), and a higher percentage of fertile eggs that hatched (P = 0.04) than DARK. In Experiment 3, LED had fewer early dead embryos (P = 0.05), lower overall embryo mortality (P = 0.04), and a higher percentage of fertile eggs that hatched (P = 0.05), and had ducklings with lower bodyweights at hatch (P = 0.04) than DARK. These results indicate that providing both white and red light during incubation can improve chick quality across poultry varieties. This type of fixture could be used to improve commercial hatchery efficiency and chick quality.

1. Forty-six flocks of commercially-reared Pekin ducks were studied in 23 houses differing in their ventilation and brooding systems, and water and feed resources, in order to identify factors affecting duck welfare in commercial practice. 2. A wide range of environmental variables were measured, together with the physical and plumage condition of the ducks at two ages, whilst companies supplied mortality and growth rate data. 3. At 23 d, more than 98% of ducks had clean eyes, nostrils and feathers and an upright posture, and 86% had no gait abnormalities. By 41 d, body condition had deteriorated slightly with 84% of ducks having clean eyes, 67% clean feathers and 79% no gait abnormalities. 4. Gait worsened with increasing temperature and litter moisture, and atmospheric ammonia concentrations. The incidence of foot pad lesions was 10% (moderate) and 3% (severe) and was positively correlated with increasing humidity and ammonia. 5. Average mortality rates were 52% for ducks reared to 335 kg at 48 d with average growth rates of 603 to 813 g/d. High temperatures correlated with high mortality and reduced growth rate; growth rate was not related to poor gait. 6. Controlling the ducks' environment, particularly temperature, humidity, litter moisture and ammonia is crucial to duck welfare. Effective ventilation systems, high quality straw and access to some form of open water were considered important for duck welfare.

Genetic selection for increased growth rate and muscle mass in broiler chickens has been accompanied by mobility issues and poor gait. There are concerns that the Pekin duck, which is on a similar selection trajectory (for production traits) to the broiler chicken, may encounter gait problems in the future. In order to understand how gait has been altered by selection, the walking ability of divergent lines of high and low growth chickens and ducks was objectively measured using a pressure platform, which recorded various components of their gait. In both species, lines which had been selected for large breast muscle mass moved at a slower velocity and with a greater step width than their lighter conspecifics. These high-growth lines also spent more time supported by two feet in order to improve balance when compared to their lighter, low-growth conspecifics. We demonstrate that chicken and duck lines which have been subjected to intense selection for high growth rates and meat yields have adapted their gait in similar ways. A greater understanding of which components of gait have been altered in selected lines with impaired walking ability may lead to more effective breeding strategies to improve gait in poultry.

Waterfowl play a key role in the epidemiology of the H5N1 subtype of highly pathogenic avian influenza (HPAI) virus; therefore, efficient immunization of domesticated ducks and geese to maximize the impact of other control measures is of great importance. A recombinant (r)HVT-AI, expressing the HA gene of a clade 2.2 H5N1 HPAI strain had been developed and proved to be efficient against different clades of H5N1 HPAI virus in chickens after a single vaccination at 1 day old and could provide long-term immunity. We investigated whether rHVT-AI applied at 1 day old is able to replicate in different species and crossbreeds of ducks and in geese with the aim of collecting data on the possible application of rHVT-AI vaccine in different species of waterfowl for the control of H5N1 HPAI. We tested the possible differences among different waterfowl species, i.e., between geese (Anser anser, domesticated greylag goose), Muscovy ducks (Cairina moschata forma domestica), Pekin ducks (Anas platyrhynchos forma domestica), and mule ducks (Muscovy duck × Pekin duck), in their susceptibility to support the replication of rHVT-AI. Vaccine virus replication was followed by real-time PCR in spleen, bursa, and feather tip samples. Humoral immune response to vaccination was tested using the hemagglutination inhibition (HI) test and H5-specific commercial ELISA. Significant differences among the different waterfowl species regarding the rate of rHVT-AI replication was detected that were not reflected by the same difference in the immune response to vaccination. Replication of the rHVT-AI vaccine was very limited in Pekin ducks, somewhat better in mule ducks, and the vaccine virus was replicating significantly better in Muscovy ducks and geese, reaching 100% detectability at certain time points after administration at 1 day old. Results indicated that the vaccine virus could establish different levels of persistent infection in these species of waterfowl. No humoral immune response could be detected either by HI test or ELISA during the tested postvaccination period (5 wk).

This study was carried out to investigate the effects of hatching egg weight and length of storage period on egg weight loss, hatchability performance and incubation length of Pekin ducks. Eggs were classified into 3 groups on the basis of egg weight such as small, medium, and large. Then, the eggs in each group were further divided into 3 storage period treatments (5, 10, or 15 days). At the end of the storage period eggs were weighted individually to determine egg weight loss. Hatching time, apparent fertility, hatchability of total and fertile eggs, and embryonic mortality were determined to measured hatching success. Egg weight loss during the storage period significantly affected by egg weight and length of storage period (P < 0.001, P < 0.05). Differences for the hatching time, apparent fertility, hatchability of total and of fertile eggs, embryonic mortality in the storage period groups were found significant (P < 0.001). The results of this study showed that effects of the hatching egg weight and length of storage on hatchability was similar to other kind of poultry. In general, hatchability was more affected by length of egg storage period.

This study was carried out to determine the hatching egg characteristics, embryo development and yolk absorption during incubation, hatch window, and hatchability of Pekin duck eggs of different weights. A total of 960 hatching eggs was obtained from a breeder flock 35 to 36 wk of age. The eggs were classed into 3 weight categories: "light" (L; 83 g). The albumen weight was the highest in the heavy eggs, whereas the yolk weight was higher in the medium and heavy eggs. Egg breaking strength was the highest with a value of 2.5 kg/cm(2) in light eggs, whereas the thinnest eggshell (0.3862 mm) was observed in heavy eggs. pH of albumen and yolk was similar and ranged from 8.8 to 8.9 and 5.9 to 6.0, respectively. On d 14 of incubation, yolk sac weight was found higher in the medium and heavy eggs. Additionally, the dry matter of the embryo and yolk sac differed among the egg weight groups during the incubation period. Interestingly, on d 25 of incubation, the embryo weight was higher in the light and heavy eggs (35.2 and 36.3 g, respectively) than in the medium eggs (29.8 g). These findings showed that embryo growth was affected by yolk absorption and dry matter accumulation. The hatchability of total and fertile eggs was lower for the heavy eggs than the light and medium eggs. The chick weight was 42.8, 48.4, and 54.9 g in light, medium, and heavy eggs, respectively. A percentage of 34.2, 36, and 31.6% of chicks from light, medium, and heavy eggs, hatched between 637 and 648 h, 39.6, 36.2, and 32.9% between 649 and 660 h, 26.2, 27.8, and 35.5% between 661 and 672 h of incubation, respectively. In conclusion, hatching egg quality, embryo development and yolk absorption during incubation, hatch window, and hatchability were affected by egg weight in Pekin ducks.

Highly pathogenic avian influenza (HPAI) A virus H5N8 was detected in far east Asian countries during 2014 and emerged in late 2014 in European countries. Hungary reported a HPAI A(H5N8) outbreak during late winter of 2015 at a Pekin duck fattening facility. Epidemiologic monitoring was extended to holdings in neighboring areas and nearby habitats used by wild birds but failed to identify the source of infection. In addition to respiratory symptoms, the affected birds showed lethargy and neuronal signs, including torticollis. Consistent with this finding, influenza A virus antigen was detected in large quantity in the brain. Molecular analysis of the identified strain showed very close genetic relationship (and >99% nucleotide sequence identity) with co-circulating HPAI A(H5N8) strains. A number of unique or rarely detected amino acid changes was detected in the HA (T220I, R512G), the M2 (I39M), the NA (T211I), the NS1 (P85T), and the PB2 (I261V) proteins of the Hungarian strain. Further studies are needed to demonstrate whether any of these mutations can be linked to neuroinvasiveness and neurovirulence in ducks.

The transmission routes of duck astrovirus CPH (DAstV/CPH) and its pathogenicity in duck embryos were investigated. Using a reverse transcription-polymerase chain reaction (RT-PCR) developed in this study, DAstV/CPH was detected in 23/50 fresh droppings of breeder ducks, 39/65 breeding eggs, 26/31 dead embryos, and 6/10 newly hatched ducklings, which were taken from a Pekin duck farm where DAstV/CPH had previously been identified. This finding, and the detection of DAstV/CPH in 36/130 dead-in-shell duck embryo samples collected from different hatcheries located in six provinces, suggests that the virus may be horizontally and vertically transmitted and associated with hatchability problems. Inoculation and repeated passages in embryonating duck eggs resulted in isolation of DAstV/CPH. The virus caused severe chorioallantoic membrane lesions as well as growth retardation and embryo mortality, indicating that DAstV/CPH is pathogenic for duck embryos. The effect of DAstV/CPH on hatching was confirmed by an embryo infection experiment in which 8/10 9-day-old duck embryos inoculated with the third passage of DAstV/CPH were unable to hatch, with most embryos succumbing in the final stage of incubation. The use of RT-PCR on the hatched ducklings provided evidence that the embryos could develop into infected ducklings.

Here we describe the cloning and expression of Pekin duck IL-10 (duIL-10) and a six exon-5 intron structure of an IL-10 gene. Two transcripts encoding duIL-10 with an alternatively spliced 3'UTR, and a transcript lacking exon 5 with a novel coding sequence for its C-terminus (duIL-10ΔE5) were isolated from splenocytes. The duIL-10 protein has an amino acid identity of 79% and 47% with chicken and human IL-10, respectively. The duck IL-10 gene shares a similar structure of the respective exons 1-5 with the IL-10 genes of other vertebrates but has an alternative exon. The duIL-10 3D structure by homology modeling was similar to that of the human IL-10 monomer, whereas the predicted duIL-10ΔE5 protein lacks helix F. DuIL-10 and duIL-10ΔE5 transcripts were most abundant in primary and secondary immune organs and lung. Recombinant duIL-10 suppressed duck IL-2 transcripts in mitogen-activated PBMCs. Our observation suggests evolutionary conservation of structure and function of the duIL-10 protein but the roles of the novel IL-10 splice variants in the regulation of duck immune responses and evolution of vertebrate immunity remain to be elucidated.

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.

Mazowiecka 28, 85-084 Bydgoszcz, Poland(Received 4 July 2011; revised version 27 October 2011; accepted 12 March 2012) ABSTRACTThe effect of the level of maize distiller’s dried grains with solubles (DDGS) in diets for ducks and duration of the fattening period on feed efficiency, body weight, carcass and meat quality was studied. One hundred and sixty commercial Pekin ducklings were divided randomly into four groups (four replicates, each). From 1 to 21 days of age all birds received the same commercial feed, then from day 22 to 56 the ducks were fed with a diet containing one of four levels of DDGS (%): 0 (control), 15, 25 or 30. All ducks were weighed individually at 1, 21, 49 and 56 days of age and feed intake and feed efficiency were calculated. At 49 and 56 days of rearing, 10 birds with body weights close to the average weight for the group were chosen from each group, slaughtered and the following parameters were evaluated: weight of eviscerated carcass with neck, neck without skin, wings with skin, breast and leg muscle, edible giblets (heart, liver, gizzard), skin with subcutaneous fat, abdominal fat, remainder of carcass, as well as the physical and chemical characteristics of breast meat. Inclusion of maize DDGS in amounts up to 25% in the diet of ducks from day 22 of rearing had no adverse effect on the variables studied, regardless of age at slaughter. Moreover, it allowed decreasing the soyabean meal and wheat contents from 18.0 and 41.6% in the control feed to 10.0 and 24.1% in the 25% DDGS feed, respectively.KEY WORDS: DDGS, Pekin ducks, body weight, feed efficiency, carcass quality, breast meat

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.

The aim of this study was to determine the effects of a 16L : 8D photoperiod on growth performance, carcass characteristics, relative organ weight, meat composition, and blood parameters in Pekin ducks. A total of 120 (60 male and 60 female) ducklings were used in the research. Each sex group was randomly allocated into 2 photoperiod groups, 24L : 0D and 16L : 8D. Ducks reared under the 24L : 0D photoperiod had higher body weight gain (P < 0.001); feed intake (P < 0.001); percentage of breast, wings, and skin with subcutaneous fat percentage (P < 0.001); and abdominal fat (P < 0.05). Sex of ducks affected body weight gain (P < 0.05; P < 0.001) and feed intake (P < 0.05) at days 1-42, as well as ash of thigh meat (P < 0.001) and creatine kinase level (P < 0.05). The present study concluded that the body weight gain and carcass development of ducks reared under the 24L : 0D photoperiod was superior to those reared under the 16L : 8D photoperiod. A 24L : 0D photoperiod is recommended for growth and carcass development in intensive Pekin duck-rearing systems.