• Asian-Australasian Journal of Animal Sciences
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• 제32권11호
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• pp.1753-1762
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• 2019

Objective: The study was aimed to compare carcass traits, physicochemical and textural properties of meat in two different genotypes of Pekin ducks with regard to sex effect. Methods: The study involved 120 Pekin ducks: 30 males and 30 females of strain P33 (Polish native Pekin ducks) and 30 males and 30 females of Star 53 HY (commercial hybrid Pekin ducks). At 49 d of age, 48 birds (12 males and 12 females of each genotype) were selected for dissection. After the dissection, meat samples were collected to determine meat quality traits. Results: The studied Pekin ducks of different genotype showed significant differences in body weight, carcass weight, dressing percentage, as well as percentages of breast muscles, skin with subcutaneous fat, abdominal fat, neck, and remainders of eviscerated carcass with neck. Duck genotype influenced the content of crude protein, crude fat, Na, K, P, Zn, $pH_{24}$, electric conductivity ($EC_{24}$), cooking loss, $L^{\star}$, $a^{\star}$, most textural traits of breast muscle, and also Na, Mg and Fe content, $EC_{24}$, drip loss, cooking loss and $L^{\star}$, $a^{\star}$, and $b^{\star}$ colour coordinates of leg muscles. Regardless of genetic origin, males exhibited higher BW, carcass weight and carcass neck percentage, as well as lower redness, hardness, chewiness and gumminess of breast muscle compared to females. The genotype${\times}$sex interaction was significant for the crude fat content and cooking loss of breast muscle, and for the yellowness of leg muscle. Conclusion: Star 53 HY ducks are more suited for broiler production due to their higher body weight and dressing percentage. Their breast and leg meat are characterized by more beneficial chemical composition but has poorer sensory and textural properties compared to the meat of P33 ducks.

• Asian-Australasian Journal of Animal Sciences
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• 제31권10호
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• pp.1575-1580
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• 2018

Objective: This study was conducted to estimate the genetic parameters and breeding values of breast meat related traits of Pekin ducks. Selection response was also determined by using ultrasound breast muscle thickness (BMT) measurements in combination with bosom breadth (BB) and keel length (KL) values. Methods: The traits analyzed were breast meat weight (BMW), body weight (BW), breast meat percentage (BMP) and the three parameters of breast meat (BB, KL, and BMT). These measurements were derived from studying 15,781 Pekin ducks selected from 10 generations based on breast meat weight. Genetic parameters and breeding value were estimated for the analysis of the breeding process. Results: Estimated heritability of BMW and BMP were moderate (0.23 and 0.16, respectively), and heritability of BW was high (0.48). Other traits such as BB, KL, and BMT indicated moderate heritability ranging between 0.11 and 0.28. Significant phenotypic correlations of BMW with BW and BMP were discovered (p<0.05), and genetic correlations of BMW with BW and BMP were positive and high (0.83 and 0.66, respectively). It was noted that BMW had positive correlations with all the other traits. Generational average estimated breeding values of all traits increased substantially over the course of selection, which demonstrated that the ducks responded efficiently to increased breast meat yield after 10 generations of breeding. Conclusion: The results indicated that duck BMW had the potential to be increased through genetic selection with positive effects on BW and BMP. The ultrasound BMT, in combination with the measurement of BB and KL, is shown to be essential and effective in the process of high breast meat yield duck breeding.

• 한국동물학회지
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• 제25권2호
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• pp.71-80
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• 1982

中國産 집오리, Anas platyrhynchos의 肝 alkaline phosphatase의 特性에 대해 觀察하여, 다음과 같은 結果를 얻었다. 1. 이 酵素는 分子의 크기가 다른 2가지 酵素種을 가짐을 보였다. 各 酵素分子는 各各 電氣泳動 速度가 다른 2가지 分子로 이루어 짐을 알았다. 2. 이 효소의 最適 pH는 9.0임이 판명되었고, 다른 포유류 酵素에 比해 熱에 대한 安定度가 낮았다. 3. $Mg^2+$은 이 酵素의 活性을 약 2배 증가 시켰으나, $Ca^2+$은 活性에 거의 影響을 주지 않았다. 4. Phosphate 이온은 이 효소에 대해 competitive, L-phenylalanine은 uncompetitive 阻害劑로 作用함을 알았다.

• Journal of Animal Science and Technology
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• 제61권6호
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• pp.305-312
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• 2019

This study was carried out to investigate the effects of dietary energy levels on growth performance, blood parameter, and intestinal morphology of Pekin ducks in low temperature. A total of 500, 21-d-old Pekin ducks (initial BW = 1,089 ± 5.21 g) were evenly assigned to five dietary treatments (2,950, 3,000, 3,050, 3,100, or 3,150 kcal AME/kg, calculated on an as-is basis) with four replicates (pens) for each treatment (25 ducks per pen). During the experiment, hens were provided with feed and water ad libitum. Overall, increasing dietary energy levels corresponded to an increase of final body weight and body weight gain (linear, p < 0.01). Feed intake decreased (linear, p < 0.01) and feed conversion ratio increased (linear, p < 0.01) with increasing levels of energy. There were no significant differences (p < 0.05) in the level of leukocytes between groups. However, heterophils decreased (quadratic, p < 0.05) and lymphocytes increased (linear, p < 0.01) as inclusion of dietary energy levels increased. The H/L ratio increased (linear, p < 0.01) with increasing dietary energy levels while serum corticosterone levels decreased at overall experimental periods. Triglycerides increased (linear and quadratic, p < 0.05) with increasing dietary energy levels. There were no significant changes in villus height or crypt depth of the jejunum at overall experimental. In conclusion, increasing concentrations of dietary energy levels up to 2,950-3,150 kcal/kg in diet. Additionally, 3,150 kcal/kg dietary energy had been revealed more beneficial and could be practiced as protective management for the Pekin ducks reared under low ambient temperature (8℃ to 10℃).

• Asian-Australasian Journal of Animal Sciences
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• 제29권12호
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• pp.1742-1747
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• 2016

A $2{\times}5$ factorial experiment, using 2 dietary methionine levels (0.28% and 0.48%) and 5 dietary choline levels (0, 394, 823, 1,239, and 1,743 mg/kg), was conducted to study the effects of dietary methionine status on choline requirements of starter white Pekin ducks from 7 to 28 days of age. Four hundred eighty 7-d-old male White Pekin ducks were randomly allotted to ten dietary treatments, each containing 6 replicate pens with 8 birds per pen. At 28 d of age, weight gain, feed intake, and feed/gain were measured and the legs of all ducks from each pen were examined for incidence of perosis. Perosis and growth depression were observed in choline-deficient ducks and supplementation of choline reduced perosis and significantly increased weight gain and feed intake regardless of dietary methionine levels (p<0.05). In addition, significant positive effects of dietary methionine supplementation on weight gain, feed intake, and feed/gain were observed at any choline level (p<0.05). Supplementation of 1,743 mg/kg choline in diets alleviated the depression of weight gain and feed intake caused by methionine deficiency at 0.28% methionine level. The interaction between choline and methionine influenced weight gain and feed intake of ducks (p<0.05). At 0.28% methionine level, 1,743 mg/kg choline group caused 4.92% and 3.23% amount of improvement in weight gain and feed intake compared with 1,239 mg/kg choline group, respectively. According to the broken-line regression, the choline requirements of starter Pekin ducks for weight gain and feed intake were 1,472 and 1,424 mg/kg at 0.28% methionine level and 946 and 907 mg/kg at 0.48% methionine level, respectively. It suggested the choline recommendations of starter Pekin ducks on a semi-purified diet were 1448 mg/kg at 0.28% methionine level and 927 mg/kg at 0.48% methionine level, respectively. Compared with the adequate methionine level, menthionine deficiency markedly increased the choline requirements of ducks.

• Journal of Animal Science and Technology
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• 제64권3호
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• pp.471-480
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• 2022

This experiment was conducted to determine the maximum dietary energy levels on growth performance and carcass characteristics of White Pekin duck. the Six dietary treatments were formulated based on their apparent metabolizable energy (AME) concentrations from 2,700 to 3,200 kcal/kg with a 100 kcal/kg gap to evaluate the accurate dietary AME requirement to address current knowledge and further issues for fulfilling the genetic potential of meat-type white Pekin ducklings. A total of 432 one-day-old male White Pekin ducklings were randomly allocated into one of six dietary treatments with six replicates (12 birds per pen). The diets were formulated as corn-soybean meal-based diets to meet or exceed the Nutrient Requirement of Poultry specification for meat-type ducks. Growth performance indices (i.e. average daily gain [ADG], average daily feed intake, feed conversion ratio) were measured weekly. Medium body weight (BW) ducklings from each pen were sacrificed to analyze the carcass traits and abdominal fat content on day 21. Obtained data were analyzed to estimate significant effect using the one-way ANOVA of IBM SPSS Statistics (Version, 25). If the p-value of the results were significant, differences in means among treatments were separated by Tukey's post hoc test. Significant differences were then analyzed with a linear and quadratic broken model to estimate the accurate concentration of AME. Ducklings fed higher dietary AME diets increased (p < 0.05) BW, ADG. Ducklings fed higher AME than 2,900 kcal/kg diets increased abdominal fat accumulation and leg meat portion. The estimated requirement by linear plateau method showed from 3,000.00 kcal/kg to 3,173.03 kcal/kg whereas the requirement by quadratic plateau method indicated from 3,100.00 kcal/kg to 3,306.26 kcal/kg. Collectively, estimated dietary requirements exhibit diverse results based on the measured traits and analysis methods. All the estimated requirements in this experiment present higher than previous research, the maximum requirement for the next diet formulation should be selected by the purpose of the diet.

• 한국환경과학회지
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• 제26권2호
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• pp.265-268
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• 2017

The objective of this study was to evaluate the characteristics of duck litter in ducks fed diets containing Houttuynia cordata powder. One-day-old ducklings (Pekin) were randomly divided into two groups and fed a control or 1% H. cordata powder-containing diet for an experimental period of three weeks. The results showed that pH for 1-2 weeks and total nitrogen for 1-3 weeks in duck litter were affected by dietary treatments with 1% H. cordata powder (P < 0.05). For Volatile Fatty Acids (VFAs), there was no significant difference (P > 0.05) between ducks fed 1% H. cordata and control diets, as shown in the results for acetic acid and propionic acid in duck litter over three weeks; but, this was not the case for propionic acid at 3 weeks. The inclusion of 1% H. cordata powder in the diet had a the positive effect on increasing the total nitrogen and decreasing pH and VFAs in duck litter.

• 한국환경과학회지
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• 제28권8호
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• pp.709-712
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• 2019

The effect of insect feed powder on the growth performance and economic evaluation of ducks was investigated. One hundred and twenty-old Pekin ducks were randomly assigned to two dietary treatments (0% and 1% Hermetia illucens powder) with three replicates of 20 birds each for 14-42 d. No significant (p>0.05) difference in growth performance between the control and 1% H. illucens powder was observed, except the feed conversion ratio (p<0.05), for the experimental period. The treatments with 1% H. illucens powder improved the economic indicators in comparison with the controls. Therefore, a diet supplemented with 1% H. illucens powder could significantly improve the feed conversion ratios and increase the economic indicators.

• 한국환경과학회지
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• 제27권9호
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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.

• 한국축산식품학회지
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• 제32권5호
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• pp.578-583
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• 2012

The purpose of this study was to evaluate the ultrastructural and shear force changes of duck breast and leg meat during aging at $0^{\circ}C$. Pekin ducks (45 d old) purchased from Greemud Co. were used for this experiment, and were stored at $0^{\circ}C$ for 7 d in order to determine the changes of the meat structure using transmission electron microscopy (TEM) and shear force. At day 0, A-band, I-band, M-line and Z-line of sarcomeres were seen clearly, but sarcomeres started to lose structure and become extended in length from day 2. With extended aging periods, myofibrils were destroyed and symptoms of aging became more obvious. In the duck breast meat, some myofibrils were also destroyed at the Z-line, but were mainly destroyed at the M-line. The change in structure of duck leg meat over time was similar to that of breast meat. After five days and seven days of aging, mitochondria size and quantity were determined to be increased between the myofibrils. Shear force was decreased over time. From this study, aging at $0^{\circ}C$ was found to negatively influence the ultrastructure and shear force of duck meat.