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Production, composition, and quality of duck eggs
Abstract
The duck egg has become increasingly more important in the world because of its nutrition and less capital input is required to produce it. This chapter discusses duck egg production, duck breeds, and productive styles in the world. A comparison of duck eggshell, egg white, and egg yolk composition between different avian species is given. Duck products include the salted egg, pidan (peedan, century egg, thousand-year egg, alkalized egg), balut (embryonic egg), ω-3 fatty acids-enriched egg, and yolk pigment-enhanced egg. Last, we discuss the factors affecting the quality of duck eggs and products.
... Owing to the varieties in laying duck species used in the world, the weight range of duck egg is 60-90 g (Huang and Lin 2011). The percentages of eggshell, egg white and egg yolk relative to egg weight account for 11-13%, 45-58% and 28-35%, respectively (Huang and Lin 2011). ...
... Owing to the varieties in laying duck species used in the world, the weight range of duck egg is 60-90 g (Huang and Lin 2011). The percentages of eggshell, egg white and egg yolk relative to egg weight account for 11-13%, 45-58% and 28-35%, respectively (Huang and Lin 2011). The egg composition is mainly influenced by the age. ...
... As that of hen eggs, it is easy to modify the fatty acid composition of duck egg yolk by using different dietary lipid sources. Huang and Lin (2011) reported various studies concerning the enrichment of egg yolk with long chain n-3 polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) by including fish oil or fish meal in diets. The increase in EPA and DHA of egg yolk was obtained after 1 week of feed distribution when diets contained 5 and 6% refined cod liver oil and 2 weeks when diets contained 2, 3 or 4% refined cod liver oil (Chen and Hsu 2003). ...
Asia contributes significantly to world’s duck population. Asian countries like China, Vietnam, Indonesia, Malaysia, and Bangladesh have a high number of ducks. Cambodia is the duck predominant country with a share of 40.5% ducks in total poultry, while Bangladesh is the most duck dense country in the world with 438.8 ducks per square kilometer area. The world duck population increased by sixfold from 193.4 million heads in 1961 to 1177.4 million heads in 2019. The growth curve has three phases: a slow and steady early growth from 1961 to 1985 with annual growth rate (AGR) of 5.0%, a fast growth phase from 1985 to 2010 (AGR = 7.3%), and a stationary phase from 2010 onwards with AGR of −0.17%. The first human death due to avian influenza (AI) in Hong Kong in 1997, reemergence of highly pathogenic avian influenza (HPAI) in 2003 and spreading to new territories in 2007 caused significant slumps in duck production. France ranks second in duck meat production after China, although it holds seventh position in duck population. Nearly 80% of the down and feathers are produced in China. Out of the total 195.6 million kilos of duck meat exported in 2019, 71% emanated from Europe. The per capita availability of duck meat was high in European countries like Hungary (9570 g) and France (3460 g). Apart, Europe is the major exporter of live birds, with France alone contributing more than half. During the recent 5 years, the reduction of human cases of AI has signaled the revival of duck farming. Location-specific technological interventions are to be carried out to refine the existing practices and to sustain duck farming.
... Agree with Puspitasari (2010) the average egg weight of Tegal duck is 65-70 g / grain, Alabio duck 65-70 g / grain, Bali duck 49 g / grain and Mojosari duck 65 g. Huang and Lin (2011) added that because of the large number of varieties in laying duck species spread throughout the world, the weight range of duck eggs is 60-90 g. Percentage of eggshell, egg white and egg yolk from all eggs, each accounted for 11-13%, 45-58%, and 28-35% respectively. ...
... From each egg produced from the treatment, the eggshell color is bluish green which indicates that almost all eggs produced are of good quality. According to Huang and Lin (2011) eggshell quality is better observed in blue egg duck eggs compared to white shell skin. The cuticle on the blue duck eggshell is good and firm compared to the interstitial structure that is spread on white duck eggshells. ...
... The mean egg white index during the study of each treatment is presented in Table 5 . Huang and Lin (2011) the index of egg white during storage at 2 -44ºC has an albumin index of around 0.061 -0.079. eggs at a temperature of 2ºC -37ºC with a storage time of 7 -37 days having an index ranging from 0.09 -0.10. ...
This study aims to determinate the effect of combination golden snail powder and fermented coconut cake on quality of duck eggs. We were using experimental feeds combination form golden snail powder and fermented coconut cake as raw material for livestock rearing for duck. This research was conducted in July - September 2018 in Mangkoso Village, Barru Regency and continued with sample testing at the Laboratory Animal Husbandry Faculty of Livestock Product Technology University of Hasanuddin. This study used 16 female duck who are 20 weeks old with four types of treatments consists of four replications of each treatment. The egg quality was carried out using a sample of 16 eggs from Ducks which was maintained and treated with different rations. The data obtained were analyzed using variance analysis with a Completely Randomized test for significant different results. The results of the combination of golden snail powder and fermented coconut cake on egg color, egg white index, egg yolk index, haugh unit (HU) value of egg units. All treatments (P1, P2, P3) gave effect to three parameters, namely eggshell quality, egg yolk index and egg yolk color, while the other three parameters namely egg weight, egg white index and Haugh Unit (HU) value did not differ significantly from negative controls. The best treatment was shown by treatment P3 which gave an effect on the heavier egg weight than other treatments, eggshell quality grade A, Egg White Index and Egg Yolk Index showed good quality and bright golden egg yolks.
... In order to get visible coagulation, the duck egg albumen needs to be heated to 55°C (131°F) for 10 min compared with 30 min for the chicken egg white. Duck egg yolk has a relatively higher fat and cholesterol content than chicken yolk (Huang and Lin, 2011). Considering these compositional aspects, the use of duck eggs in pasta or noodles production is worthy of investigation. ...
... Quail, pheasant, turkey, and goose eggs, having albumen to yolk ratios similar to chicken eggs (Huang and Lin, 2011), all seem to be suitable for pasta production. Pigeon eggs have a higher proportion of albumen (74%) with respect to chicken eggs which range from 57% to 63% (Huang and Lin, 2011), thus the albumen to yolk ratio is in favor of good pasta structuring. ...
... Quail, pheasant, turkey, and goose eggs, having albumen to yolk ratios similar to chicken eggs (Huang and Lin, 2011), all seem to be suitable for pasta production. Pigeon eggs have a higher proportion of albumen (74%) with respect to chicken eggs which range from 57% to 63% (Huang and Lin, 2011), thus the albumen to yolk ratio is in favor of good pasta structuring. However, the use of eggs of these species is hindered by their very limited and seasonal production (Tseverni-Goussi and Fortomaris, 2011). ...
Eggs are multifunctional ingredients, used in a number of food products due to their diverse technological properties. In pasta, they are added to improve nutrition, color, texture, and cooking behavior. After a brief introduction on egg pasta nomenclature and government regulation of its egg content, the production processes of fresh and dry egg pasta are illustrated with emphasis on the structuring role of eggs. Changing the natural albumen to yolk ratio is suggested as a useful tool for modulating egg pasta quality. The exploitation of egg structuring capacities for gluten-free pasta production is discussed as well as the potential use of nonchicken eggs in pasta formulation. Finally, analytical methods for egg content and quality determination in pasta are reviewed.
... This increased percentage of albumen was probably caused by high protein and essential amino acids content in golden snail (Subhan et al., 2010;Ghosh et al., 2017) as a protein constituent in albumen with an average amount of 8.8% to 12.15% (Quan & Benjakul, 2018;Chaiyasit et al., 2019). According to Huang & Lin (2011), the main proteins in duck albumen are ovalbumin (40%), ovotransferrin (2%), ovomucoid (10%), lysozyme (1.2%), and ovomucin(3%). The average of eggshell weight ranged from 11.99% to 12.92% and eggshell thickness ranged from 0.37 mm to 0.44 mm. ...
... The average of eggshell weight ranged from 11.99% to 12.92% and eggshell thickness ranged from 0.37 mm to 0.44 mm. The standard of eggshell weight was 11% to 13% (Huang & Lin, 2011). According to Śiątkiewicz et al. (2015), Ca is the most important nutritional factor to determine the eggshell quality, and 95% of the shell is made up of calcium carbonate. ...
The objective of this study was to evaluate the effect of feeding cassava leaf meal and golden snail on performances, chemical, and physical qualities of local duck egg. The experiment used 180 Pajajaran laying ducks of 20 weeks of age and was offered dietary treatments up to 26 weeks of age. The experiment was conducted in a completely randomized design with a 3 x 2 factorial arrangement. The first factor was the treatment of cassava leaf meal consisted of 3 levels, i.e., 0%, 5%, and 10%. The second factor was the treatment of golden snail consisted of 2 levels, i.e., 0% and 10%. Each experimental unit used three replicates and each replicate consisted of ten ducks. The results showed that there was no interaction effect of cassava leaf meal and golden snail treatments on laying duck performances and egg qualities. There were significant effects of cassava leaf meal and golden snail treatments (p0.05) by treatments of cassava leave meal and golden snail. The utilization of 10% cassava leaf meal in the diet significantly improved egg production, feed intake, egg mass, and yolk color (p
... Although egg compositions from traditional domestic species share common characteristics [189,190], they possess some significant differences in terms of energy that are mostly explained by the change in relative proportion of yolk to egg white ( Figure 4). The energy (kcal/100g) for chicken, quail, duck, goose, and turkey eggs is 143, 158, 185, 185, 171, respectively. ...
... While the relative amount of proteins remains stable between species (about 13%), the lipid proportion varies from 9.5% (chicken) to more than 13% (duck, goose) ( Figure 4, which explains most of the variation in their respective energy value. Yolks from duck and goose species have relatively higher fat content and higher percentage of yolk compared to chicken egg [189]. In parallel, the lipid profile of egg yolk exhibits some specificities depending on species [191][192][193]. ...
Egg is an encapsulated source of macro and micronutrients that meet all requirements to support embryonic development until hatching. The perfect balance and diversity in its nutrients along with its high digestibility and its affordable price has put the egg in the spotlight as a basic food for humans. However, egg still has to face many years of nutritionist recommendations aiming at restricting egg consumption to limit cardiovascular diseases incidence. Most experimental, clinical, and epidemiologic studies concluded that there was no evidence of a correlation between dietary cholesterol brought by eggs and an increase in plasma total-cholesterol. Egg remains a food product of high nutritional quality for adults including elderly people and children and is extensively consumed worldwide. In parallel, there is compelling evidence that egg also contains many and still-unexplored bioactive compounds, which may be of high interest in preventing/curing diseases. This review will give an overview of 1) the main nutritional characteristics of chicken egg, 2) emerging data related to egg bioactive compounds, and 3) some factors affecting egg composition including a comparison of nutritional value between eggs from various domestic species.
... Additionally, less capital input is required for its production. [1] Egg albumen has been considered as an excellent source of protein and contains several bioactive compounds. Lysozyme possesses bacteriostatic, bacteriolytic, and bacteriocidal activity. ...
... Ovalbumin (40%) and ovotransferrin (2%) are considered as the main proteins found in duck albumen. [1] Under reducing condition, ovalbumin was also found as predominant. Proteins with MW of 77 and 14 kDa considered as ovotransferrin and lysozyme, respectively, were also observed. ...
Desugarization of duck albumen using glucose oxidase/catalase was optimized before drying. Optimum condition for desugarization using response surface methodology was as follows: glucose oxidase 31.24 units and catalase 781 units/mL albumen and incubation time of 6.55 h at 30 °C. Foaming capacity (FC) and foam stability (FS) were enhanced, while the solubility decreased after desugarization. This coincided with the increase in surface hydrophobicity (p < 0.05). Higher trypsin inhibitory activity was found in freeze-dried albumen powder than spray-dried counterpart. Trypsin inhibitory activity was continuously decreased as the inlet temperature for spray-drying increased (p < 0.05). Desugarization could increase FC and FS, but slightly decreased solubility of powders. No marked differences in protein patterns were observed in all the powders, regardless of desugarization and drying methods. L* of albumen powder decreased but ΔE, a*-, b*-values and browning index increased as spray-drying temperatures increased (p < 0.05). Therefore, prior desugarization could lower browning and increased foaming property of duck albumen, particularly when spray-dried with inlet temperature of 160 °C.
... Although the protein content of egg white and egg yolk was lowered in ducks fed DSGLE, the figures were still higher than those of egg white (8.60%-10.50%) and egg yolk (14.10%-16.0%) of various kinds of ducks [55,56]. In another study in chickens, DSGLE feeding did not change egg protein contents [24]. ...
Objectives
The use of dried star gooseberry leaf extract (DSGLE) in rations and its effects on the egg internal quality of local ducks were examined.
Materials and Methods
A total of 100 9-month-old local ducks weighing 1,406.25 ± 211.32 gm were randomly allocated into 5 treatments and 5 replicates in a completely randomized design. The birds were reared in 25 battery cages (4 birds each) and fed rations containing 0, 0.5%, 1.0%, 1.5%, and 2.0% DSGLE.
Results
Eggs of ducks fed DSGLE had significantly lower saturated fatty acid (SFA) (30.66%–32.53%) than those of control ducks (36.23%). Egg polyunsaturated fatty acids (PUFA) increased from 2.29% (control) to 2.61% (2.0% DSGLE) and 2.76% (1.5% DSGLE), while egg monounsaturated fatty acid (MUFA) contents were not significantly different. The fatty acids of the whole edible part of eggs (albumen + yolk) were composed mainly of MUFA (40.19%–44.34%), followed by SFA (30.66%–36.22%), and PUFA (2.29%–2.76%). Malondialdehyde contents were reduced from 6.07 to 4.92 µg/gm (19%) in egg yolk and from 1.50 to 0.62 µg/gm (59%) in egg white, and thiobarbituric acid reactive substances values of the eggs were reduced from 0.93 to 1.65 (77%). The egg cholesterol level of ducks fed 2% DSGLE (21.94 mg/gm) was about 28.5% lower than that of eggs from control ducks (30.67 mg/gm) of eggs of control ducks. The egg white and egg yolk protein contents (12.31% and 16.35%) of treated ducks were lower than those in the control group (13.58% and 17.47%).
Conclusion
The inclusion of SGLE in rations could be used to produce healthy duck eggs with no oxidative damage.
... On the other hand, the TL district is considered a highland where the altitude above sea level is higher than the BJ district. Huang and Lin [30] contended that environmental factors highly influence the production performance of ducks. Further studies are required to investigate the traits' variability, repeatability, and heritability under similar environmental conditions. ...
Objective:
This study aimed to examine the diversity of phenotypic characteristics of female Alabio ducks (Anas platyrhynchos Borneo) and their eggs in South Kalimantan, Indonesia.
Materials and methods:
A total of 200 18-month-old ducks and 300 eggs were selected using a survey method with multistage random sampling. These samples were obtained from two districts in the province of South Kalimantan [Banjar (BJ) districts and Tanah Laut (TL)]. The observed data were analyzed descriptively with variations using the independent t-test for each location. Principal component analysis (PCA) was deployed to assess the overall variance and define variables with greater discriminatory power between individuals.
Results:
The observations on the body's physical characteristics and the eggs of Alabio ducks showed significant differences between ducks from BJ and TL areas (p < 0.05) except for yolk diameter, albumen height, albumen index, and Haugh unit (HU) (p > 0.05). Most egg quality traits from BJ were greater than those from TL, which include egg weight, egg length, egg width, yolk weight, albumen weight, shell weight, shell thickness, and egg shape index. The PCA revealed medium-to-high communalities in the phenotypic body characteristics of Alabio ducks and their eggs.
Conclusion:
Significant physical characteristics and egg quality differences were found between the two locations, except for the albumen index and HU, with substantial variability within each trait. These traits could explain the total variation in the phenotypic characteristics of female Alabio ducks.
... The Pekin ducks and Muscovy ducks are bred to produce meat whereas Khaki Campbell and Indian Runner are bred for egg production (Ismail et al., 2010;Aronal et al., 2012;Arthur, 2017). In Malaysia, the common breeds for egg production are the local Java ducks and Khaki Campbell (Nurkhoeriyati et al., 2011;Huang & Lin, 2011). Khaki Campbell are well known for their laying ability. ...
... Such a constancy has only been noted in the case of parameters corresponding to chicken eggs, and possibly eggs of other poultry species. In this context, we can rely on the data based on measurements of duck eggs [50][51][52] and goose eggs. [53][54][55][56] In other words, only those eggs of bird species intensively domesticated by humans appear to conform, notwithstanding the 21 species found in this study (Table 3) Given that the neutral axis golden ratio applies predominantly to species domesticated by humans over many generations, it seems reasonable to suggest that it was directed artificial selection that contributed to the production of ovoids with these "golden" geometric parameters. ...
Avian eggs represent a striking evolutionary adaptation for which shell thickness is crucial. An understudied eggshell property includes the neutral axis, a line that is drawn through any bent structure and whose precise location is characterized by the k‐factor. Previous studies have established that, for chicken eggs, mean k corresponds to the golden ratio (Φ = 1.618, or 0.618 in its reciprocal form). We hypothesized whether such an arrangement of the neutral axis conforms to the eggshell of any bird or only to eggshells with a certain set of geometric parameters. Implementing a suite of innovative methodological approaches, we investigated variations in k of 435 avian species, exploring which correspond to Φ. We found that mean k is highly variable among birds and does not always conform to Φ, being much lower in spherical and ellipsoid eggs and higher in pyriform eggs. While 21 species had k values within 0.618 ± 0.02 (including four falcon species) and the Falconinae subfamily (six species) revealed a mean of 0.618, it is predominantly domesticated species (chicken, ducks, and geese) that lay eggs whose neutral axis corresponds to the golden ratio. Thus, the study of the mathematical secrets of the eggshell related to the golden ratio of its neutral axis suggests its species‐specific signatures in birds. An understudied eggshell property is the neutral axis, a line that is drawn through any bent structure and whose precise location is characterized by the k‐factor. Chicken eggs have a mean k corresponding to the golden ratio (Φ = 1.618). We hypothesized whether such an arrangement of the neutral axis conforms to the eggshell of any bird or only to eggshells with a certain set of geometric parameters. We investigated variations in k of 435 avian species, exploring which correspond to Φ.
... Duck egg production is typically less structured than the chicken egg industry (Huang and Lin, 2011), often with home breeding of birds, lower biosecurity standards and multiple age production, which limit the opportunities for all-in-all-out management. Moulting of birds is done frequently, or old birds from large producers may be sold on to smaller producers after a year of lay. ...
Salmonella Enteritidis is considered the only pathogen currently posing a major risk of egg-borne diseases in the European Union (EU). The possible impact of extending the shelf-life of eggs on the risk to consumers posed by S. Enteritidis was estimated by applying a quantitative model and comparing the actual situation regarding the storage of eggs in the EU with different possible scenarios combined, considering the prolongation of the best-before and the sell-by date from 7 to a maximum of 70 days. Extending the sell-by date by one week (from 21 to 28 days), but leaving the best-before date unchanged, is estimated to result in a relative risk of illness of 1.4 and 1.5 for uncooked and lightly cooked egg meals respectively, compared to the current situation. If the best-before date is also extended by one week (from 28 to 35 days), the relative risk would be 1.6 and 1.7. In the worst case scenario considered (sell-by date of 42 days, best before date of 70 days), such figures would be 2.9 and 3.5. It should be noted that the absolute risk is greater for uncooked meals compared to lightly cooked meals. An effective way to minimise any increase in risk during extended storage is to keep the eggs refrigerated both at retail and the household. Regarding egg spoilage, such events strongly depend on the hygienic conditions of egg production and practices of egg handling, including storage times and temperatures. Finally, the impact of the prolongation of storage time on the quality criteria for eggs (3-hydroxybutyric acid and lactic acid) destined for manufacturing of egg products is considered negligible.
... In addition, different salting period could influence the protein content in salted duck egg white (Kaewmanee et al. 2009a). Genetics, nutrition, age, and raising environment could also influence the quality of duck eggs, which will affect the composition of salted duck eggs (Huang and Lin, 2011). ...
The objective of this study was to utilize salted duck egg white as an alternative source of salt for yellow alkaline noodles (YAN). YAN with salted duck egg white (YAN‐EW) was formulated by incorporating 15.21 g of salted duck egg white to replace the 1 g of salt. The effects of this substitution on the proximate compositions, physicochemical properties, cooking properties, textural properties and organoleptic properties of YAN were determined. YAN‐EW showed to have significantly higher ( P < 0.05) protein content, lighter and more yellowish compared to control YAN‐C. No significant difference between YAN‐EW and YAN‐C in terms of pH and cooking properties. YAN‐EW exhibited similar hardness and springiness as YAN‐C, but have significantly higher ( P < 0.05) cohesiveness and chewiness. YAN‐EW received scores on a par with YAN‐C in all sensory attributes. All the sensory attributes scored higher than 5, indicating good acceptance of YAN‐EW by the sensory panelists.
Practical Applications
High demand on traditional Chinese foods, such as mooncakes and glutinous rice dumplings, generated a large amount of waste, i.e., salted duck egg white. Potential use of salted duck egg white as a food ingredient is of great interest to the industry. The present work describes the use of salted duck egg white in yellow alkaline noodle. The main finding is that salted duck egg white showed potential to be utilized as an alternative source to table salt in noodle formulation. This information can be useful to noodle producers in utilizing “waste” as a natural source of salt.
... Its consumption was accounted for 10-30 % of total egg consumption worldwide (Pingel et al. 2009). Besides, Thailand is the second highest ranking country in the world after China for duck egg production (Huang and Lin 2011). It is, thus, important to investigate contamination of endosulfan in duck eggs. ...
Eight duck farms and a local market in Suphanburi province, Thailand adjacent to paddy fields were selected for this study. The concentrations of endosulfan isomers (α- and β-endosulfan) and endosulfan sulfate in environmental matrices (water, soil, feed) and duck eggs were determined. Human health risk via the contaminated egg consumption was also evaluated. Analysis of environmental matrices found both endosulfan isomers (α- and β-endosulfan) and endosulfan sulfate in most samples. Endosulfan sulfate was predominantly found in all matrices followed by β- and α-endosulfan, respectively. The total endosulfan concentrations were in the following order: feed > soil > water. However, the levels of endosulfan detected were lower than the regulatory maximum residue limit of endosulfan, except in water (>0.200 ng mL−1). Endosulfan sulfate in duck egg samples was also predominantly detected in both yolk and albumin. The average total endosulfan residues (∑endosulfan) in yolk (6.73 ng g−1) were higher than in albumin (4.78 ng g−1). According to principle component analysis, we found that paddy soil surrounding the duck farms is the suspected source of endosulfan contamination in husbandry water which subsequently contaminates duck eggs. The estimated daily intakes (EDIs) of these endosulfan-contaminated eggs were well below the acceptable daily intake (ADI) for endosulfan (6 μg kg−1 day−1). However, the consumption of this contaminated duck eggs should be of concerns in regard to chronic exposure. Therefore, the better environmental managements to reduce endosulfan residues can play a crucial role for decreasing human health risk.
Meloxicam is a non-steroidal anti-inflammatory drug (NSAID) commonly prescribed in an extralabel manner for treating chickens in urbanized settings. The objectives of this study were to determine meloxicam depletion profiles in eggs and ovarian follicles and to estimate associated withdrawal intervals (WDI) in laying hens following a single intravenous or repeated oral administration. The observed peak concentration of meloxicam in ovarian follicles were consistently higher than in egg yolk and egg white samples. Terminal half-lives were 31-h, 113-h and 12-h in ovarian follicles, egg yolk and egg white samples, respectively, for repeated oral administrations at 1 mg/kg for 20 doses at 12-h intervals. The terminal half-life following a single intravenous administration at 1 mg/kg was 50-h for ovarian follicles. Meloxicam WDI estimations using ovarian follicle and egg yolk concentration data following 20 doses at 12-h intervals were 36 and 12 days, respectively. Meloxicam WDI estimation using egg yolk concentration data following 8 doses at 24-h intervals was 12 days. These results improve our understanding on the residue depletion of meloxicam from chickens’ reproductive tracts and egg products and provide WDIs to help ensure food safety for humans consuming eggs from treated laying hens.
Duck egg and meat production and consumption are mainly concentrated in Asia. Different species or breeds and different production systems are used all over the world. This will affect the growth rate, body weight and slaughter age of ducks and thus, the muscle development and further meat quality. As with other poultry species, ducks can be sold as whole carcasses, cut and processed products. Owing to genetic selection and to improvements in bird management, particularly in nutrition, the meat yield of ducks has increased and carcass fattiness has decreased. Duck meat is red, and duck muscles have a higher oxidative energy metabolism than those of chickens or turkeys. Lipids are, therefore, an important component of duck meat quality. Finally, duck meat displays the characteristics of poultry meat (high level in unsaturated fatty acids representing around 60% of total fatty acids) and red meat (high level of haeminic pigment and higher level of phospholipid and total lipid contents than chicken and turkey breast meat). Owing to the varieties in laying duck species used in the world, the weight range of duck egg is 60–90 g. The egg composition is mainly influenced by the age. It is quite difficult to modify the chemical composition of eggs except the fatty acid composition and micronutrient content that can be manipulated by the way of feeding laying ducks.KeywordsProteinsLipidsFatty acidsMinerals
The consequences of chimerization and its possible influence on the productivity of chimera offspring remain poorly understood. The objects of research were ducks (Anas platyrhynchos) of the Shanma (Shan partridge duck) and Shaoxing breeds kept at the Zhuji Guowei Poultry Development Co, Ltd, P.R.China. The study was conducted in the poultry genetics laboratory of the Zhejiang Academy of Agricultural Sciences on a duck farm of Zhejiang Generation Biological Science and Technology Co., Ltd. (Zhejiang Province, PRC). To create chimeras of ducks, the method described by Aige-Gil, Simkiss, 1991; M.T. Tagirov, 2010 was used. Blastodiscs have been isolated from freshly hatched fertilized eggs using a filter paper ring. Shanma duck embryos have been used as recipients, and Shaoxing duck embryos, homozygous for plumage color gene allele (wild type), have been used as donors. Busulfan (SigmaAldrich, United States) have been used as a chemical agent that suppresses a division of primary germ cells (PGC) of recipient embryos. A hole in an eggshell (window) of recipients (Shanma breed) have been made between a blunt and sharp ends of eggs. (This reduced a distance between an injector and an embryo needle). The recipients havebeen incubated for 8–10 hours at a temperature of 38 °C. After recipient eggs incubation for 8 hours, the windows were opened in them. Busulfan was injected into the subgerminal cavity of the embryo with a micropipette (1.5–3 μl of liquid). After busulfan injection, the empty cavity was filled with culture medium (RPMI-1640) supplemented with antibiotics (ampicillin, streptomycin), the hole was closed by plastic wrap and adhesive tape. The eggs have been incubated at a reduced temperature (+32 °C) for 24 hours with the aim of prolong the duration of busulfan action on the PGC (primary germ cells). More than 50% of embryos have been died in the first 2–3 days (after an incubation start). Head and neck disorders have been observed in the 1.2% of embryos. Busulfan injection at a concentration of 300 ng per egg have been leads to 95.0–96.3% mortality of duck embryos, concentration of 150 ng per egg, a mortality rate of 33.3–75.3% have been observed, concentration to 75 ng led to 18.75–38.5% of embryonic mortality. Analysis of the age of puberty (laying of the first egg) indicates that the chimeras matured later. If in the control group the average age of puberty was 139 ± 9 days, in the group of chimeras - 148 ± 13 days. Thus, we can attest that in our experiment, the chimeras matured later than the control animals, which may be due to the effect of busulfan in the sterilization of recipient embryos. The average weight of ducks in the control group was lower, and the group itself was more consolidated. Thus, in the control ducks weighed 1422.40 ± 57.00 g, the chimeras 1608.80 ± 94.76 g. The advantage of live weight chimeras over the control group may be due to the fact that the control group consisted of recipients served by Shanma animals. Egg production of ducks for the entire study period was 87.5 ± 0.05 % (control) 79.5±0.12 % (busulfan). The weight of eggs of ducks of two groups for the entire period was 70.62±0.199 g (control) and 71.15±0.157 g (p˂0.001). The eggs morphometric parameters of the studied ducks groups were: the average values of egg length were 6.056±0.0564 cm (control) and 6.269±0.1341cm (busulfan); egg breadth were 4.520±0.0053 cm (control) and 4.529±0.004 cm (busulfan). There were no statistical intergroup differences in the morphometric parameters of the eggs of the studied groups. In fact, we obtained results similar to the previous ones, which concerned the egg production of daughters of drake chimeras.
Egg internal quality traits are important traits related to egg production in poultry industry. To better understand the genetic architecture of egg internal quality traits in ducks, we performed genetic parameters estimates and a genome-wide association study (GWAS). The phenotypic values of egg weight, yolk color, albumin height (AH), yolk weight, and Haugh unit (HU) were collected individually from 352 F2 laying ducks produced by reciprocal crosses between mallards and Pekin ducks, and their genotypes were assayed by whole genome re-sequencing. The results showed that the AH and HU traits have a clear coefficient of variance, around 15% for both mallards and Pekin ducks. The pedigree-based genetic parameters estimates rane from 0.26 to 0.71 for all eight egg quality traits, while the highest heritability was 0.71 for egg weight. The GWAS showed that a clear signal was associated with AH and HU traits. The locus zoom analysis and conditional GWAS helped to narrow the candidate region to ~5.8-Mb spanning from 14.7 to 20.5 Mb on Chromosome 5, which harbored 111 candidate genes. MUC6 and LDLRAD3 were finally promised as the major candidate genes affecting albumen composition. Our data revealed the egg internal quality traits for the first time in ducks, which provides a theoretical basis and technological support for improving duck egg internal quality.
In order to explore the influence of egg-laying regulatory genes on egg production in ducks at different laying stages, Pekin duck and Black Muscovy duck were used in this study, including early laying stage (20-30 weeks old), peak laying period (31-48 weeks old) and late laying stage (49-66 weeks old). Relative quantitative RT-PCR was used to detect the mRNA transcription level of selected egg-laying regulatory genes in the ovary tissues of ducks at different laying stages. Study shows: during the laying period of Pekin duck, ESR1, LRP1, IGF-1 and LHR were involved in the regulation of egg-laying, and the high expression of LRP1 in the late stage could inhibit egg production. Still, the expression products of the other three genes showed promoting effect. During the laying period of Black Muscovy duck, FSH, VLDLR, IGF-1, PRLR, LHR and LRP1 participated in the regulation of egg-laying, in which the expression products of the first five genes could promote egg production, while LRP1 showed inhibitory effect. Through our experiments, these data will provide strong theoretical support for the breeding of Pekin duck and Black Muscovy duck.
Egg albumen is a potential source of trypsin inhibitor (TI), which has been widely used to improve textural property of surimi or surimi‐based food products. TI from duck albumen was isolated and purified using ammonium sulfate precipitation at 20%–40% saturation and affinity chromatography using trypsin‐CNBr‐activated Sepharose 4B column. TI was purified with purity and yield of 111.8‐fold and 0.6%, respectively. The purity of inhibitor was confirmed using Native‐PAGE as indicated by the presence of single band. Molecular weight of purified TI was 43 kDa based on SDS‐GAGE and gel filtration. The purified TI remained unchanged at temperatures below 60°C and the pH in the range of 7–9. The inhibitory activity of TI was decreased with the addition of salt higher than 5%. Inhibition kinetic study revealed that purified TI from duck albumen was uncompetitive inhibitor and the inhibition constant (Ki) was 508 nM. TI from duck egg albumen could serve as a food grade inhibitor for controlling undesirable proteolysis.
Practical applications
Duck egg albumen has been known to be rich in protease inhibitors, which can be used as a protein additive to enhance gelling properties of surimi or surimi‐based products. Therefore, it is of interest to isolate and purify TI from duck egg albumen. Information regarding characteristics of TI from duck albumen could be beneficial for further applications, in which duck albumen is better exploited.
The demand for duck meat and eggs in Asian countries increases every year. Duck egg albumen has become an important ingredient in the food industry alongside its hen counterpart, because of its excellent nutritive and functional properties. The major proteins in duck albumen are ovalbumin, ovomucoid, ovomucin, conalbumin, and lysozyme. Comparing with hen albumen, lower contents of ovalbumin, conalbumin, lysozyme and ovoflavoprotein are found in duck albumen. Nevertheless, duck albumen shows better gelling and foaming properties than hen albumen. During storage, duck albumen gel properties are enhanced, while foam volume and foam stability are decreased. Moreover, the changes in quality indices of duck egg including the thinning of the albumen, an increase in albumen pH, loss of water and carbon dioxide occur as storage time is increased. Some processes such as alkaline treatment also cause the loss in nutritive value of egg albumen. In this review, the composition and functional properties of duck albumen and how they are affected by processing conditions are also addressed, in comparison with hen albumen. A better understanding of duck egg albumen would be beneficial so that the food processing industry can exploit the potential of this avian protein.
The effects of desugarization using glucose oxidase/catalase and spray drying conditions on gelling properties of duck albumen powder were studied. Gelling temperatures increased as spray‐drying inlet temperatures (140‐180°C) were increased (P < 0.05). ΔE*, a*‐ and b*‐ values of gel increased but L* and whiteness decreased when higher spray‐drying temperatures were used (P < 0.05). However, whiteness and lightness of albumen gel were drastically increased after desugarization (P < 0.05). Texture profile analysis showed that hardness, springiness, gumminess and chewiness of gel decreased with increasing spray‐drying temperatures. Moreover, gel of freeze‐dried desugarized albumen powder had higher hardness, springiness, gumminess and chewiness than that of spray‐dried non‐desugarized counterpart (P < 0.05). Albumen gel prepared from desugarized albumen powder showed the compact network with more connectivity and smaller voids than that from non‐desugarized one as visualized by scanning electron microscopy, regardless of drying conditions. Prior desugarization could lower browning and increased gelling properties of duck albumen powder. Higher spray drying inlet temperature generally exhibited the adverse effect on properties of resulting albumen powder. Both desugarization and drying conditions had the profound influence on characteristics and textural property of duck egg albumen. This article is protected by copyright. All rights reserved.
Physicochemical properties, trypsin inhibitory activity, and gelling properties of albumen from duck egg during 15 days of storage at 4 °C and room temperature (28–30 °C) were studied. As the storage time increased, Haugh unit and moisture content decreased, while the pH value increased (P < 0.05). The rate of changes was lower at 4 °C. Trypsin inhibitory activity in albumen from egg stored at 4 °C was higher than that kept at room temperature throughout the storage time (P < 0.05). Nevertheless, no differences in protein patterns were observed during the storage. Based on texture profile analysis, the highest hardness, gumminess, and chewiness were found at day 3 for room temperature and at day 6 for 4 °C. Higher values were attained for eggs kept at 4 °C. Conversely, albumen gels made from eggs stored at room temperature exhibited higher cohesiveness, adhesiveness, springiness, resilience than those kept at 4 °C. The gels had the lowered whiteness when eggs were stored for a longer time, particularly at room temperature. Thus, storage condition directly affected the quality of albumen from duck egg.
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.
Duck egg white (DEW) hydrolysates were prepared by five enzymes (papain, trypsin, chymotrypsin, alcalase, and flavourzyme) and their antioxidant activities investigated in this study. DEW hydrolyzed with papain (DEWHP) had the highest peptide content among the five enzymatic treatments. Besides, the peptide content of DEWHP increased when the enzyme to substrate ratio (E/S ratio) increased. It was suggested that higher E/S ratio contributed to elevate the degree of hydrolysis of DEW effectively. Similar results were also obtained by Tricine-SDS-PAGE. In addition, SDS-PAGE patterns indicated papain was the only one amongst all enzymes with the ability to hydrolyze DEW. In antioxidant properties, DEWHP showed more than 70% of inhibitory activity on linoleic acid peroxidation and superoxide anion scavenging. Moreover, the chelating effect of DEWHP was greater than 90%, while no significant difference was observed in DPPH radical scavenging and reducing ability. The results of peptide contents, antioxidant activities and electrophoresis suggested that the higher the peptide content, the stronger the antioxidant activities in DEWHP.
Total plate counts on washed duck eggs from a breeder farm on Long Island were less than 30/shell during the winter (January to February) of 1982. Clean unwashed eggs had counts less than 9 × 10¹/shell, whereas dirty unwashed eggs had counts as high as 9 × 10⁵ /shell. Our results showed that washing with a chlorine sanitizer (under commercial conditions) was highly effective in reducing surface bacterial counts on egg shells. Prolonged storage reduced bacterial counts on clean eggs, but it did not significantly affect loads on dirty eggs. No salmonellae could be detected on shells or in the magma of all eggs examined.
In a second trial (March 1982) bacterial loads on washed and clean duck eggs from six different breeder farms were low, ranging from too few to count to 10²/shell. A higher proportion of dirty eggs were heavily contaminated with counts ranging from 10⁵ to 10⁶ /shell, but no salmonellae were detected either on shells or in magma. In the third trial (May 1982) bacterial determinations on eggs from breeder ducks that were not confined followed the pattern of the second trial. However, in this trial Salmonella enteritidis was detected on dirty egg shells in four of six farms.
In a fourth trial (May 1983), bacterial loads on washed and nest-clean eggs from the same breeder farms (not confined) ranged between 10² to 10³/shell and 10² to 10⁴ /shell, respectively. S. enteritidis and S. hadar were recovered from washed, nest clean, and dirty eggs in two of six farms.
We conclude that proper egg washing and confinement of duck breeders should minimize the problem of salmonellosis in ducklings.
At 26, 31, 36, and 42 wk of age, eggs were collected from the same duck breeder flock to study the effects of hen production
age on egg composition and embryo development. At each hen age, yolk and albumen measurements were made on a random subsample
of unincubated eggs. Embryo and yolk sac measurements were made at 20, 22, 24, 26, 27, and 28 d of incubation. Egg weight
was significantly affected by hen production age, but most of the observed age effects occurred between 26 and 31 wk with
minimal age differences thereafter due to a quantitative feed restriction for egg weight. Yolk weight increased significantly
with hen production age, with the largest increase, 6.6 g, also occurring between 26 and 31 wk of age. Yolk-free duckling
weight increased with hen production age at 27 d of incubation. The yolk sacs of embryos from the 31-, 36-, and 42-wk-old
hens were heavier at 20 and 22 d, before the differentiation in embryo weight. Differences in yolk sac weight were not consistently
affected by hen production age between 26 and 28 d of incubation. The eggs from the 42-wk-old hens weighed 3.3 g less than
those from the 31-wk-old hens, but yolk-free duckling weight at 27 d was 2.9 g heavier from the 42-wk-old hens.
The yolks of traditional chicken egg products (Tiedan, Ludan, and Chayedan) and duck egg products (raw and cooked Xiandan,
immersed and coated Pidan) were subjected to moisture, lipid, and thiobarbituric acid (TBA) determinations as well as cholesterol
and cholesterol oxidation products (COP) analysis. The main COP detected for these egg products included 20-hydroxycholesterol
and 7β-hydroxycholesterol, other types of COP were not detected. The contents of COP formed in traditional egg products varied,
depending upon the types of egg products. The cholesterol oxidation ratio for traditional Chinese chicken egg products ranged
from 1.14 to 1.75%, whereas that for traditional Chinese duck egg products ranged from 1.18 to 1.90%. Those traditional egg
products that required pickling in salt or alkaline, cooking, hot air drying, and exposure to oxygen and heat all produced
COP.
1. The dietary methionine requirement of egg-laying ducks was assessed by feeding diets supplemented with graded levels of DL-methionine (0, 4, 8, 12, 16 g/kg dietary protein) for 8 weeks. The basal diet contained 175 g protein and 2.6 g methionine per kg feed (or 14.9 g/kg protein) and an estimated ME of 11.5 MJ/kg. 2. A total of 800 Shaoxin laying ducks (420 d old) were randomly divided into 5 groups of 160 each and fed in 4 separate pens. 3. Dietary supplementation of methionine significantly increased egg production and feed conversion efficiency. 4. Dietary methionine requirement for optimum egg production was estimated to be 25.7 g/kg of dietary protein or 4.5 g/kg of the diet or 380 mg/bird-d. 5. Methionine supplementation increased the methionine level in plasma, and the free glutamic acid and aspartic acid concentrations in plasma were quadratically related to dietary methionine levels. Increasing dietary methionine had little effect on egg quality characteristics.
Salmonella enteritidis CCRC 10744 from the Culture Collection and Research Center (CCRC) and S. enteritidis strain SEP from a patient specimen, were used for the survival test in the salted duck egg and the thousand-year egg during processing and storage. After inoculation of S. enteritidis at levels of 50-100 CFU / egg yolk, the NaCl content of the egg yolk increased from 0.56% to 0.98% during processing of the salted egg. Similar growth curves were obtained for S. enteritidis CCRC 10744 and strain SEP. The viable cells increased to 10 7-10 8 CFU / g in the first 2 days and maintained 10 7 CFU / g by the end of the process. After processing, the salted eggs with S. enteritidis were stored at 25-30 °C. Five eggs were examined every month, and both strains were found in most of the eggs even after 2 months storage. Similar procedure was followed for the thousand-year egg. During processing period, the pH value of the yolk increased from 6.5 to 10.3. The changes of viable cell count in the thousand-year eggs were similar as those in the salted egg. However, due to the final alkaline pH of the egg yolk, the viable counts in the thousand-year egg decreased to about 10 6 CFU / g by the end of the process. After processing, the thousand-year eggs were also stored at 25-30°C. The viable cells of both strains decreased to roughly 10 5 CFU / g in the first month of storage. After 2 and 3 months' storage, S. enteritidis CCRC 10744 could still be found in 2 and 1 egg yolks of the 5 sampled eggs respectively, while strain SEP could be detected in all 5 eggs even after 2 or 3 months' storage.
1.1.As air temperature decreases, bill temperatures (⩾ 34°C) are described by Tbl = (33.8) + (0.12)Ta.2.2.As air temperature increases, bill temperatures (⩽26°C) are described by Tbl = 9.5) + (0.65)Ta.3.3.Vinyl-resin injections of bill vasculature show midline arteries which branch distally and continue along the bill periphery to the head.4.4.Thermography reveals three patterns of bill temperature distribution: concentric circles, horizontal bands and complex. All three patterns interchange dynamically when air temperature is above 15°C.5.5.Heat losses from the duck's bill are 18–117% of resting metabolic production at 0°C and 5–61% at 20°C, depending on bill vasomotion.