• Journal of Environmental Science International
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• v.27 no.9
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• pp.803-807
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• 2018

This study evaluated the duck growth performance and the economic benefits on using illite as a feed additive for ducks. Illite powder at three levels (0%, 1%, and 1.5%) was added to commercial duck diets, and fed to 180 one-day-old ducks (Pekin, 3 replicates, 20 ducks per pen) using a randomized block design for 39 days. During the experimental period, there were no significant growth performance differences between treatments (p>0.05), except with the feed conversion ratio (p<0.05), for all periods (8-39 days). In addition, the dietary supplementation of 1% and 1.5% illite did not significantly improve (p>0.05) Feed Intake Cost (FIC), Weight Gain Value (WGV), Meat Production Cost (MPC), Economic Efficiency (EE), Profitability (P), or cost benefit ratio for 8 to 21 d, 22 to 39 d, and 8 to 39 d. However, the differences in meat production cost and profitability between treatments were statistically significant (p<0.05) for all periods (8-39 d). In conclusion, adding 1% and 1.5% illite to duck diets is not beneficial for improving either the duck growth performance or the economic indicators.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.10
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• pp.1441-1446
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• 2009

Composition of intramuscular lipids, phospholipid classes and phospholipid molecular species in traditional Chinese duck meat products was investigated. Free fatty acids and phospholipids were identified and quantified by gas and high performance liquid chromatography, and phospholipid molecular species were determined by mass spectrometry. The results showed that raw duck meat had high quantities of phosphatidylethanolamine and phosphatidylcholine. The percentages of phospholipid classes decreased during three kinds of processing of duck meat products. A selective degradation of phospholipid molecular species with polyunsaturated fatty acids was found in dry-cured duck, but was not found in roasted and water-boiled duck products.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.3
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• pp.331-337
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• 1993

In order to understand the effect of duck hepatitis B virus (DHBV) on the economic performance of ducks, Three groups (DHBV congenitally infected, experimentally infected and DHBV negative) Brown Tsaiya ducks (Anas platyrhyncha) were used for experimental animals. Artificial insemination and pedigree hatching were applied in the propagation of ducklings, and the efficiency of vertical transmission and experimental infection was analyzed through the detection of DHBV DNA in the sera of 8-week-old offspring. The observation of the records of the first year indicated that the persistent infection had no significant effects on the performance of ducks, except the egg number of survival ducks up to 40 week of age. Thus DHBV infection did not appear to give ill effects to the economic performance of ducks in first laying year. A higher infection rate (85.3%) was obtained in congenital transmission than that (75.5%) of experimental infection. Both modes of infection did not reach 100% infectious rate, although some ducks developed transient viraemia in a tracing of DHBV DNA for 24 weeks to 11 challenged ducklings.

• Journal of Environmental Science International
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• v.27 no.10
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• pp.933-936
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• 2018

An experiment was conducted to evaluate the efficacy of a mixture of bentonite and illite as feed additives on the growth performance and litter quality of 90 Pekin ducks. The ducks were individually weighed and randomly divided into two treatments (control and 1% combination of silicate minerals), with three replicate pens per treatment, and 15 ducks per pen. Growth performance was not significantly affected (p>0.05) by the combination of bentonite and illite, but a trend of increased growth performance was observed in the control groups. Total nitrogen content and pH in the litter decreased following supplementation with the combination of bentonite and illite (p<0.05) when compared with the control group. This data indicates that the dietary supplementation with the combination of bentonite and illite (1% level) has no positive effect on the growth performance and litter quality of Pekin ducks.

• Journal of Environmental Science International
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• v.24 no.10
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• pp.1309-1313
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• 2015

The effects of Houttuynia cordata powder on the growth performance of ducks were investigated. Ninety ducks were assigned into one of three dietary treatments as a completely randomized design for 6 weeks: feeds supplemented with 1% or 2% H. cordata and a control group. No significant difference was observed in feed conversion among the three groups (p > 0.05), but addition of H. cordata had a significantly positive effect (p < 0.05) on initial and final body weight, weight gain, and feed intake of the ducks. Furthermore, the effects of chemical treatment (comprising 50 g and 100 g aluminum chloride [$AlCl_3$] per kilogram litter) on the ammonia ($NH_3$) flux in duck litters were also investigated. Duck litter was treated with $AlCl_3$ at a depth of 8 cm by top-dressing; this resulted in a significant difference on $NH_3$ flux (p < 0.05) during the experimental period (but not at 2 weeks). $NH_3$ flux at 6 weeks were reduced by 25.4% and 37.5% by treatment with 1% and 2% H. cordata, respectively, compared with the control groups. In conclusion, enriching the diets of the ducks with 2% H. cordata and adding 100 g $AlCl_3$ to their litter has beneficial effects on increasing their growth performance and reducing $NH_3$ flux in their environment.

• Journal of the Korean Geographical Society
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• v.50 no.2
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• pp.217-237
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• 2015

Seokchon Lake, and the area surrounding it, have become symbolic with an environment of 'peace', 'delight', 'happiness', and 'healing' due to the large floating yellow rubber duck which sits within the lake. There exists, however, a hidden intention of a large corporation who wishes to make benefit of this installation and its healing properties. Nevertheless, the lake has become a hot destination for people to come and see the rubber duck and take romantic photos with it. The photographs taken and shared further expand the popularity and romantic environment of the duck and lake. This process is a perfectly hermeneutic circle. Self or group mediation through photographic performances with the rubber duck has allowed the lake to take on new meaning to visitors. For families taking photos together it has become a place of family bonding and love while for couples of any age it has been transformed into a place to express their love through pictures together with the duck. Even for selfie generation it has become a destination and muse. Tourists are not merely written upon, but are also enacting and inscribing places with their own stories. Therefore, photographic performances produce rather than consume and reflect geography of Seokchon lake.

• Korean Journal of Agricultural Science
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• v.45 no.4
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• pp.879-888
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• 2018

This research was done to develop a standard management checklist for duck farmers. To this end, experts in commercial duck farming participated in making a blueprint for a standard management checklist. This expert group consisted of ten members which included the researcher, a professor, an extension advisor and leading farmers in commercial duck farming. By collecting knowledge on commercial duck farming from these experts, a management performance index was made, and checking factors were designated. As a result of this expert survey, management outcome indicators and subdivision evaluation indicators were established. To confirm these results, a first stage Delphi expert survey was carried out. As a result, the experts were not in agreement with the farming scale of 1 - 4 levels and 2 levels in the management outcome indicators. Additionally, the experts were not in agreement on the choice of feed in the feeding management and the cooperative management system as well as the utilization of agricultural information in managing the business. The factors that did not have the same opinion among experts were surveyed by a second Delphi survey asking whether experts approve the requested value. As a result of the second Delphi survey, all factors have an approval rate that have a value of more than 90%. Finally, a standard management checklist was established based on the research result.

• Animal Bioscience
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• v.37 no.4
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• pp.678-688
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• 2024

Objective: Reduced crude protein (CP) diets offer potential benefits such as optimized feed efficiency, reduced expenses, and lower environmental impact. The objective of this study was to evaluate black soldier fly larvae (BSFL) meal on a low-protein diet for duck performance, blood biochemical, intestinal morphology, gastrointestinal development, and litter. Methods: The experiment was conducted for 42 days. A total of 210-day-old male hybrid ducklings (5 replicate pens, 7 ducks per pen) were randomly assigned to 6 dietary treatments (3×2 factorial arrangements) in randomized design. The factors were CP level (18%, 16%, 14%) and protein source feed soybean meals (SBM), black soldier fly larvae meals (BSFLM). Results: Reduced dietary CP levels significantly decreased growth performance, feed intake, the percentage of nitrogen, pH (p<0.05), and tended to suppress ammonia in litter (p = 0.088); increased lipid concentration; and enhanced relative weight of gastrointestinal tracts (p<0.05). In addition, dietary BSFL as a source of protein feed significantly increased lipid concentration and impacted lowering villus height and crypt depth on jejunum (p<0.05). Conclusion: In conclusion, the use of BSFLM in a low-protein diet was found to have a detrimental effect on growth performance. However, the reduction of 2% CP levels in SBM did not have a significant impact on growth performance but decreased nitrogen and ammonia concentrations.

• Journal of Ocean Engineering and Technology
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• v.33 no.2
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• pp.116-122
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• 2019

Among the various wave power systems, Salter's duck (rotor) is one of the most effective wave absorbers for extracting wave energy. The rotor shape is designed such that the front part faces the direction of the incident wave, which forces it to bob up and down due to wave-induced water particle motion, whereas the rear part, which is mostly circular in shape, reflects no waves. The asymmetric geometric shape of the duck makes it absorb energy efficiently. In the present study, the rotor was investigated using WAMIT (a program based on the linear potential flow theory in three-dimensional diffraction/radiation analyses) in the frequency domain and verified using OrcaFlex (design and analysis program of marine system) in the time domain. Then, an experimental investigation was conducted to assess the performance of the rotor motion based on the model scale in a two-dimensional (2D) wave tank. Initially, a free decay test (FDT) was carried out to obtain the viscous damping coefficient. The pitch response was extracted from the experimental time series in a periodic regular wave for two different wave heights (1 cm and 3 cm). In addition, the viscous damping coefficient was calculated from the FDT result and fluid forces, obtained from WAMIT, are incorporated into the final response of the rotor. Finally, a comparative study based on experimental and numerical results (WAMIT & OrcaFlex) was performed to confirm the performance reliability of the designed rotor.

• Journal of Environmental Science International
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• v.27 no.5
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• pp.345-348
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• 2018

The influence of various forms of Houttuynia cordata with fermented red koji as feed additives on the performance of duck livestock was evaluated through a field study. Two hundred and forty ducks (Pekins) aged 0-38 d were used. They were randomly assigned to four treatment groups (0%, 1% H. cordata powder with fermented red koji, 1% H. cordata pelleted with fermented red koji, and 1% H. cordata coated with fermented red koji) with four replicates (15 ducks per replication). Foreconomic evaluation, the data (a total of 240 duck) obtained from each treatment were applied to 10,000 ducks per treatment 38-d after the feeding trial. Overall, the results of economic evaluation were the highest in the treatment with 1% H. cordata coated with fermented red koji, followed by 1% H. cordatapelleted with fermented red koji, 1% H. cordatapowder with fermented red koji, and control. In conclusion, using 1% H. cordatawith fermented red koji as coating and pellet type duck diets might be of economic advantage for sustainable environmental management.