• Journal of Environmental Science International
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• v.30 no.3
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• pp.289-293
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• 2021

This study was conducted to investigate the distribution of duck production in duck housing as a function of the breeding period. The items in duck production distribution included body weight, feed intake, feed conversion ratio, and average duck production. All data were based on eight cycles (June and December, 2017; February, June, August, September, and November, 2018; February, 2019) at Farm Site 1 through 7. The most optimal results in the duck production distribution were observed at Site 1 for weight gain, feed intake, and feed efficiency. This could be explained by the fact that Site 1 was well managed in environmental improvement and sustainability. Based on these data, selective alternatives to improve duck production in duck farms are recommended as follows: first, proper management and recording of litter used as a flooring material are required, and second, continuous management such as temperature, relative humidity and ventilation is needed. Lastly, it is necessary to change duck facilities by introducing environmental management techniques. Furthermore, efforts to improve the overall facilities and management of duck breeding farms through additional field studies are needed in the future.

• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.277-281
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• 2013

The experiment was undertaken to see the effects of Bacillus sp. on the growth performance and disease resistance to Salmonella sp. infections. The use of probiotic microbes in poultry is commonly practiced. In this study, Bacillus subtilis was tested using a total of 120 chicks of age of 1 day after hatching. The growth traits examined were body weight gain and feed conversion rate. And also, the Salmonella resistance of Bacillus subtilis was tested after the chicks were orally administered with Salmonella pullorum by gavage force injections. The result showed that Bacillus subtilis yielded a high feed efficiency, consequently increased growth rate. For the effect of Bacillus subtilis on Salmonella infection, Bacillus subtilis significantly improved the resistance to Salmonella pullorum infection. Various clinical symptoms of Salmonella infection were highly decreased by addition of Bacillus sp.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.5
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• pp.503-512
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• 2012

There is a new power generation system such as direct coal fuel cell (DCFC) with a solid oxide electrolyte operated at relatively high temperature. In the system, it is of great importance to feed coal continuously into anodic electrode surface for its better contact, otherwise it would reduce electrochemical conversion of coal. For that purpose, it is required to improve the electrochemical conversion efficiency by using either rigorous mixing condition such as fluidized bed condition or just by recirculating coal particle itself successively into the reaction zone of the system. In this preliminary study, we followed the second approach to investigate how significantly particle recycle would affect the coal conversion efficiency. As a first phase, coal conversion was analyzed and evaluated from the thermochemical reaction of carbon with air under particle recirculating condition. The coal conversion efficiency was obtained from raw data measured by two different techniques. Effects of temperature and fuel properties on the coal conversion are specifically examined from the thermochemical reaction.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.7
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• pp.961-966
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• 2008

Direct and maternal genetic parameters for production traits in 1,642 pigs and maternal genetic correlations among production (1,642 pigs) and feed efficiency (380 boars) traits were estimated in 7 generations of a Duroc population. Traits studied were daily gain (DG), intramuscular fat (IMF), loineye area (LEA), backfat thickness (BF), daily feed intake (FI), feed conversion ratio (FCR) and residual feed intake (RFI). The RFI was calculated as the difference between actual and predicted feed intake. The predicted feed intake was estimated by adjusting the initial test weight, DG and BF. Data for production traits were analyzed using four alternative animal models (including direct, direct+maternal permanent environmental, or direct+maternal genetic+maternal permanent environmental effects). Direct heritability estimates from the model including direct and all maternal effects were $0.41{\pm}0.04$ for DG, $0.27{\pm}0.04$ for IMF, $0.52{\pm}0.06$ for LEA and $0.64{\pm}0.04$ for BF. Estimated maternal heritabilities ranged from $0.04{\pm}0.04$ to $0.15{\pm}0.05$ for production traits. Antagonistic relationships were observed between direct and maternal genetic effects ($r_{am}$) for LEA (-0.21). Maternal genetic correlations of feed efficiency traits with FI ($r_g$ of FI with FCR and RFI were $0.73{\pm}0.06$ and $0.90{\pm}0.05$, respectively) and LEA (rg of LEA with FCR and RFI were $-0.48{\pm}0.05$ to $-0.61{\pm}0.05$, respectively) were favorable. The estimated moderate genetic correlations between direct and maternal genetic effects for IMF and LEA indicated that maternal effects has an important role in these traits, and should be accounted for in the genetic evaluation system.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.2
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• pp.167-170
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• 2017

Objective: The feed intake (FI) and feed efficiency are economically important traits in ducks. To obtain insight into this economically important trait, we designed an experiment based on the residual feed intake (RFI) and feed conversion ratio (FCR) of a random population Pekin duck. Methods: Two thousand and twenty pedigreed random population Pekin ducks were established from 90 males mated to 450 females in two hatches. Traits analyzed in the study were body weight at the 42th day (BW42), 15 to 42 days average daily gain (ADG), 15 to 42 days FI, 15 to 42 days FCR, and 15 to 42 days RFI to assess their genetic interrelationships. The genetic parameters for feed efficiency traits were estimated using restricted maximum likelihood (REML) methodology applied to a sire-dam model for all traits using the ASREML software. Results: Estimates heritability of BW42, ADG, FI, FCR, and RFI were 0.39, 0.38, 0.33, 0.38, and 0.41, respectively. The genetic correlation was high between RFI and FI (0.77) and moderate between RFI and FCR (0.54). The genetic correlation was high and moderate between FCR and ADG (-0.80), and between FCR and BW42 (-0.64), and between FCR and FI (0.49), respectively. Conclusion: Thus, selection on RFI was expected to improve feed efficiency, and reduce FI. Selection on RFI thus improves the feed efficiency of animals without impairing their FI and increase growth rate.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.9
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• pp.1319-1325
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• 2002

Two experiments were conducted to evaluate the effect of early feed restriction on growth, feed conversion ratio (FCR) and mortality in unsexed broiler chickens. In Experiment 1, 350 one-day-old broiler chickens were divided into 7 groups. Each treatment group was represented by five replicates of ten broilers each. One group was fed ad libitum as the control group and the other six groups were fed 25% ad libitum (25% multiplied by amount of feed intake of ad libitum chickens at the previous day) for 4 or 6 days, 50% ad libitum for 4 or 6 days, and 75% ad libitum for 4 or 6 days. In experiment 2, 500 broiler chickens were divided into 10 groups. Each treatment group was represented by five replicates of ten broilers each. One group was fed ad libitum as the control group. Three ages of feed restriction initial timing (2, 4 or 6 days of age) and three types of feed restriction (physical restriction, meal feeding and diet dilution) were used ($3{\times}3$) in both experiments. They were feed-restricted for 6 days. Results showed that restricted broilers exhibited compensatory growth in both experiments except for diet dilution groups. In both experiments, FCR of restricted broilers was higher, whereas feed intake of them was lower during restriction period. FCR of restricted broilers was lower upon refeeding. Mortality was inconsistently affected by early feed restriction. Leg abnormality was lower in restricted broilers in both experiments. Level of feed restriction significantly influenced body weight, FCR and feed intake of restricted broilers (p<0.05), but duration of feed restriction had no effect. Type of restriction significantly affected body weight, feed intake and FCR (p<0.05). It appeared that to achieve the best result (complete compensatory growth and better FCR), broilers should be restricted at 25% ad libitum for 6 days (Experiment 1). Meal feeding started at 2 days of age would show the best performance (Experiment 2).

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.2
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• pp.230-234
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• 2005

The purpose of this experiment was to study the effect of varying levels of tryptophan on the performance and carcass character of broiler. Trial 1: Ninety-six, five-week-old male Hubbard chickens, average weight 1.97 kg, were used in the trial. All birds were allocated into 3 treatments of 32 birds each. Each bird was kept in an individual cage. The trial period was 3 weeks. Treatment 1: Tryptophan content 0.198%. Treatment 2: Tryptophan content 0.228%. Treatment 3: Tryptophan content 0.258%. Trial 2: Ninety-six, three-week-old male Hubbard chickens, average weight 1.23 kg, were randomly distributed into the following two treatments. Each treatment had 48 birds. Treatment 1: Tryptophan content 0.167%. Treatment 2: Tryptophan content 0.198%. Trial 3: Ninety-six, twoweek-old Hubbard chickens, average body weight 0.72 kg, were used in this experiment. There were three treatments as follows. Treatment 1. Tryptophan content 0.136%. Treatment 2. Tryptophan content 0.167%. Treatment 3. Tryptophan content 0.198%. The result of Trial 1 showed that the feed intake, performance, and carcass characteristics were not influenced by tryptophan content in the diet which between 0.198% and 0.258% (p>0.05). There was no significant difference (p>0.05) in feed intake in either treatment in Trial 2. However, weight gain, feed conversion efficiency, and most carcass characteristics in the 0.198% treatment were significantly better (p<0.05) than in the 0.167% treatment. There was a trend that feed intake increased with increasing level of tryptophan, but there was no significant difference in Trial 3. The weight gain and feed conversion efficiency were significantly reduced for the broiler in the 0.136% treatment. This series of experiment showed that broilers need about 0.198% of tryptophan.

• Environmental Engineering Research
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• v.17 no.2
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• pp.89-94
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• 2012

Pyrolysis/gasification technology utilizes an energy conversion technique from various waste resources, such as biomass, solid waste, sewage sludge, and etc. to generating a syngas (synthesis gas). However, one of the major problems for the pyrolysis gasification is the presence of tar in the product gas. The tar produced might cause damages and operating problems on the facility. In this study, a gliding arc plasma reformer was developed to solve the previously acknowledged issues. An experiment was conducted using surrogate benzene and naphthalene, which are generated during the pyrolysis and/or gasification, as the representative tar substance. To identify the characteristics of the influential parameters of tar decomposition, tests were performed on the steam feed amount (steam/carbon ratio), input discharge power (specific energy input, SEI), total feed gas amount and the input tar concentration. In benzene, the optimal operating conditions of the gliding arc plasma 2 in steam to carbon (S/C) ratio, 0.98 $kWh/m^3$ in SEI, 14 L/min in total gas feed rate and 3.6% in benzene concentration. In naphthalene, 2.5 in S/C ratio, 1 $kWh/m^3$ in SEI, 18.4 L/min in total gas feed rate and 1% in naphthalene concentration. The benzene decomposition efficiency was 95%, and the energy efficiency was 120 g/kWh. The naphthalene decomposition efficiency was 79%, and the energy yield was 68 g/kWh.

• Korean Journal of Poultry Science
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• v.9 no.1
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• pp.17-33
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• 1982

The purpose of this experiment is to clarify the additional effect of antibiotics for the chicken breeding feed. This experiment was carried out with 6,560 individuals which were collected from four farms, Dugil, Hyubhoi, Sanggog and Kumsan. The duration of this experiment was 6 months from July to December in 1981. 1. Body weight and body gain. (1) The range of the body gain was 1.91-7.60% The most effective sections was T$_3$, and the effect was T$_2$, T$_4$, T$_1$, T$\sub$5/ in order. (2) The environmental sanitation of the Sanggog farm was not so good. In this farm the body gain was severely occurred in T$_3$ and T$_2$ sections. Mere gain obtained from T$\sub$5/ section. (3) The environmental sanitation was good in Dugil, Hyubhoi and Kumsan. A little body gain was occurred in these farms, but differences were shown according to the place or breeds. 2. Amount of feed intake feed conversion ratio. (1) Amount of feed intake was increased 0.13-3.19%, and feed conversion ratio was improved 1.68-4.62% compared with control. T$_3$ section showed high percent and T$_4$ T$_1$, T$\sub$5/, Is, C in order. (2) The keeping method of the chicken breed in Hyubhoi was floor brooding. From Hyubhoi and Sanggog farms, the efficiency was increased 9.4-9.8%. (3) From Dugil and Kumsan, the rate of improvement was low. 3. Mortality : Mortality was merely decreased in Sanggog and Kumsan farms which the sanitary and fowl caring conditions had been had, by additional antibiotics. But there was no worthy effect. 4. The ratio of carcass and the degree of skin coloration. The additional antibiotics in feed had no effect on the ratio of carcass but had the influence on the yellowish skin coloration. Skin coloring was good in T$\sub$7/ section and T$_1$, T$\sub$6/, T$_4$, C, T$_3$, T$\sub$5/, T$_2$ in order. 5. Economical efficiency (1) The addition of the antibiotics in feed increased 3.76-10.95% of gross earning. The highest earning was occurred in T$_4$ section and T$_3$, T$_1$, T$_2$, T$\sub$5/, C sections in order. (2) The earning rate was influenced by the antibiotic products. (3) In Dugil and Kumsan farms, there was no difference in earning, however, in Hyubhoi and Sanggog farms there was wide difference in earning. Conclusionally, the addition of antibiotics in chicken breeding feed is necessary. Especially in bad condition of environmental sanitation and floor brooding, the effect of additional antibiotics is clear. Selection of antibiotics from various kinds, maker's confidence and quality problems are important.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.5
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• pp.470-477
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• 2010

The IGCC (Integrated gasification combined cycle) is known for one of the highest efficiency and the lowest emitting coal fueled power generating technologies. As the core technology of this system is the gasifier to make the efficiency and the continuous operation time increase, the research about different coal's gasification has been conducted. Our research group had set-up the coal gasifier for the pilot test to study the effect of different coals-Shenhua and Adaro coal- on gasification characteristics. Gasification conditions like temperature and pressure were controlled at a fixed condition and coal feed rate was also controlled 30 kg/h to retain the constant experimental condition. Through this study we found effects of coal composition and $O_2$/coal ratio on the cold gas efficiency, carbon conversion rate. The compounds of coal like carbon and ash make the performance of gasifier change. And carbon conversion rate was decreased with reduced $O_2$/coal ratio. The optical $O_2$/coal ratio is 0.8 for the highest cold gas efficiency approximately. At those operating conditions, the higher coal has the C/H ratio, the lower syn-gas has the $H_2$/CO ratio.