• Korean Journal of Poultry Science
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• v.8 no.1
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• pp.1-5
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• 1981

In trying to predict the effect of genetics on the broiler in the year 2000, this is a relatively short period of time as far as broiler genetics in concerned. Modern broiler genetics started around 1945 and tremendous gains when made in past 35 years. Futher improvements on broiler will depend on the evolution and revolution: 1. Evolution: (1) Growth rate has been made 4-5% per year. (2) Feed conversion has improved approximately 1% per year. (3) Abdominal fat is becoming a major complaint in broiler. (4) Because of the changing life-style, broiler meat sales in the future will be more and more in cut-up form. (5) Breeding for stress resistance and selection for docile temperament can be important in order to funker improve fled efficiency. (6) In female parent stock, reproduction characteristics are in many can negatively correlated with the desired broiler traits. (7) Egg production and hatchability in moot commercial parent nod m at a fairly high level. (8) In male parent stock, the heavier and mon super-meat-type male lines are desired to Product better broilers. 2. Revolution: Trying to forecast revolutionary change in broiler genetics is highly speculative, as sudden change are aften unpredictable. (1) Species hybridization, such as a turkey-chicken cross (2) Biochemical tools, such as blood typing. (3) Mutation breeding by radiation or chemical mutagentia. (4) Broiler breeding would be to change the phenotypic appearance by single gene, such as naked, wingless. (5) Changes in production techniques. such as growing in cage or growing in filtered air positive pressure houses.

• Korean Journal of Environment and Ecology
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• v.23 no.6
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• pp.528-534
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• 2009

Styan's Grasshopper Warblers (Locustella pleskei) are vulnerable species distributed in East-Asia only. Its known breeding sites in Korea are remote islets including Hongdo Islet, Chilbal Islet, Mara Islet, and Chuja Islets, and, therefore, the breeding biology of this species is still poorly known. This study was conducted on Mara Islet (N $33^{\circ}$ 06', E $126^{\circ}$ 16') from May to September 2008 to investigate the breeding status and breeding site characteristics of the grasshopper warblers. A total of 11 breeding pairs and their nests were found on trees and shrubs at artificially planted forests and hedges of Pinus thunbergii. The grasshopper warblers preferentially utilized the shrub trees for nesting places, and major nesting trees were Camellia japonica, Pittosporum tobira and Pinus thunbergii as nesting trees. Average heights of nesting trees and nests were $2.77{\pm}1.10m$ and $1.75{\pm}0.56m$, respectively. The grasshopper warblers selected lower shrubs and trees for nesting than randomly selected ones around them, probably to avoid strong and prevailed winds in flat and un vegetated environments on Mara Islet. The shape of nests was a round bowl-type, and measurements of nests were $11.9{\pm}0.5cm$ in exterior nest diameter, $11.1{\pm}1.1cm$ in height of exterior nest, $5.8{\pm}0.4cm$ in interior nest depth, and 6.0cm in interior nest diameter. It incubated eggs until the early August on Mara islet, and incubation periods of Mara Islet was possibly later than that of other areas. Furthermore, the clutch size in the study area was three, and they laid smaller number of eggs than normal clutch size (4~5 eggs) reported in other areas. Although we could not observe any nest predator on this species in the study area, selective cutting and pruning of trees will diminish dense shrub layer of forests. Therefore, it may affect the breeding of this threatened species which prefers dense shrubs of artificially planted forest of Pinus thunbergii. This study suggests that detailed and consistent further research on breeding biology and habitats of the grasshopper warblers are needed to conserve and manage of Pinus thunbergii forests on Mara Islet as an important breeding site of Styan's Grasshopper Warblers.

• Korean Journal of Poultry Science
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• v.30 no.4
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• pp.245-251
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• 2003

Three experiments were conducted to investigate the effect of feeding yeast accumulated transgenic ferritin(FRT, Saccharomyces cerevisiae) as a probiotic on the performance, iron contents in the liver, spleen, bone and yolk of laying hens and broiler chicks. Effects of feeding FRT were compared with that of feeding wild-type yeast(W0) and yeast grown on 20 mM ferric citrate-added medium (W20). In Expt 1, to investigate the effect of feeding yeast (control, W0 FRT) on performance and iron content of organs of broiler chicks which were fed basal diet supplemented with 75mg/kg iron(Fe75) or not (Fe0), three hundred sixty one-day-old male broiler chicks were fed a corn-sov based diet for five weeks. Weight gain, feed intake and feed conversion were measured weekly. In Expt 2, fifteen 33-week-old ISA Brown laying hens were placed in individual cages and were fed control, W0 and FRT diets for Four weeks. In Expt 3, twenty four 45-week-old ISA Brown laying hens were placed in individual cages and were fed a basal diet for a week. Then, experimental diets (control, W0, W20, FRT) were fed for three weeks. Iron contents in the liver, heart, spleen and tibia were determined at the end of all experiments. Iron content in yolk was measured weekly (expt 2, 3). The level of yeast added and iron concentration of FRT were $1{\times}10^8$cfu/kg diet and 500 mg/kg cell (DM) respectively in Expt 3, yeast was supplemented at $2{\times}10^{10}$cfu/kg diet and the iron content of FRT was 1000mg/kg cell (DM). In Expt 1. birds fed Fe75 showed significantly higher weight gain compared with Fe0 (P<0.05). However, weight gain and feed intake of birds fed FRT was significantly lower than control (P<0.05). In Expt 2, the iron content of the liver was decreased in the FRT treatment (P<0.05). In Expt 3, iron concentration of the liver and spleen tended to be increased by feeding FRt. However, the iron content of the tibia tended to be decreased in the FRT treatment. These results suggest that feeding FRT as a probiotic cannot improve performance and iron content in organs of broiler chicks and laying hens.

• The Korean Journal of Mycology
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• v.27 no.4 s.91
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• pp.256-273
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• 1999

Seventy two isolates of Cordyceps militaris collected from 11 sites in Korea, including two isolates from ATCC, were used to assess genetic variation within Cordyceps militaris. The anamorph stage and cultural characteristics of C. militaris were observed through microscope and investigated on PDA respectively. The anamorphs of C. militaris were identified to be Verticillium. Isolates of C. militaris showed different growth rates, morphology and color. Fifty six isolates of single ascospore and seventy two isolates of mass ascospore from C. militaris were analysed using by Random Amplified Polymorphic DNA (RAPD) for genetic relationship analysis. Fifty six single ascospore isolates fell into two groups by phenogram constructed from distance values using the UPGMA method in NTSYS-pc software: group A from artificial fruit body of C18 except for isolate 51; group B from artificial fruit body of C738. The average genetic distance value within group A is 0.150 and group B is 0.163. The average genetic distance value between the two groups is 0.221. The average genetic distance value within 56 single ascospores is 0.207 and 72 mass ascospores is 0.330. Genetic relationships were not found among 72 mass ascospore isolates obtained from eleven geographically distant populations.

• Korean Journal of Food Science and Technology
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• v.11 no.1
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• pp.1-7
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• 1979

This experiment was carried out to investigate the nutritive value of brewery's activated sludge on the performance and nutrients utilization of egg type chicken of babcock fed the different levels of sludge. The chemical composition, content of amino acids and mineral in brewery's activated sludge were also analyzed. 3,6,9 and 12% of brewery's activated sludge were supplemented with basal ration as a substituted ingredient to soybean oil meal in experimental ration. The results obtained were as follow: 1. Chemical composition analysis 1) Brewery's activated sludge had 42.50% of crude protein on the air dried basis, and had 15,69% of crude ash, and had 2,060 kcal of metabolizable energy per kg of sludge. 2) Total amino acid content of brewery's activated sludge was 42.50% and 99% crude protein of brewery's activated sludge was a true amino acid, and brewery's activated sludge contained especially more methionine and threonine that those of soybean oil meal. 3) In case of mineral content of brewery's activated sludge, phosphorus, magnesium, copper and iron were plentifully included. However, calcium content in brewery's activated sludge was very low. 2. Feeding trial 1) Body gain of chicken fed the different levels of sludge was decreased in proportion to increasing level of sludge was decreased in proportion to increasing level of sludge. However, no statistical differences were found out between treatments. 2) Diet intake of chicken fed the different levels of sludge was significantly (p<0.05) increased as the supplementation level of sludge in ration increased. 3) Feed conversion of chicken fed the different levels of sludge was high in proportion to increasing level of sludge in ration. However, there were no significant differences between treatments. 3. Digestion trial 1) Utilization of dry matter of chicken fed the different levels of sludge was decreased as the level of sludge in ration increased. However, no statistical differences were found out between treatments. 2) Utilization of crude protein of chicken fed the different levels of sludge was significantly (p<0.01) increased as the level of sludge was higher. Utilization of crude protein of control treatment and of sludge 3% treatment was higher than that of other treatments. 3) Utilization of crude ash of chicken fed the different levels of sludge was significantly (p<0.05) decreased in proportion to increasing level of sludge in ration. 4) Utilization of NFE of chicken fed the different levels of sludge was slightly decreased in proportion to increasing level of sludge in ration. However, no statistical differences were found out between treatments. Therefore according to this experiment, it may be concluded that brewery's activated sludge can be supplemented with chicken ration by $6{\sim}9%$.

• Applied Biological Chemistry
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• v.5
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• pp.7-21
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• 1964

가잠(家蠶)(Bombyx mori)의 잠체(蠶體), 용체 및 견사선(絹絲腺)(후부(後部))에서 phenol법(法)으로 RNA를 추출(抽出)하여 RNA의 nucleotide 조성(組成)(mole ratio)을 살피는 한편, 견사선(絹絲腺)(후부(後部))에서 초원심법(超遠沈法)으로 r-RNA, s-RNA를 분리(分離)하여 이에 대(對)한 nucleotide조성(組成)을 조사(調査)하고 또 가잠견사선(家蠶絹絲腺)과 비교(比較)할 목적(目的)으로 거미 방적선(紡績腺)의 t-RNA를 분리(分離)하여 nucleotide성분(成分)을 측정(測定)하여 다음과 같은 결과(結果)를 얻었다. 1) 잠란(蠶卵)에 있어서 이것을 마수(磨粹), 탈지(脫脂) 후(後) lysozyme을 작용(作用)시키고 10% NaCl용액(溶液)으로 가열(加熱) 추출(抽出)하는 새방법(方法)을 고찰(考察)하여 RNA의 추출(抽出)이 극난(極難)한 잠란(蠶卵)에서 RNA를 분리(分離)하는데 성공(成功)하였다. 2) 가잠란(家蠶卵), 잠체(蠶體), 용체 및 견사선(絹絲腺)(후부(後部))의 t-RNA nucleotide 조성(組成)은 다음과 같다. 시료(試料) $\frac{G+C}{A+U}$ $\frac{G+U}{A+C}$ $\frac{Pu}{Py}$ 가잠란(家蠶卵)의 RNA 1.14 1.24 0.99 가잠체(家蠶體)의 RNA 1.40 1.36 0.80 용체의 RNA 1.40 1.33 1.35 후부견사선(後部絹絲腺)의 RNA 1.05 1.32 1.15 이로서 잠체(蠶體). 용체 및 견사선(絹絲腺)의 Pu/Py는 각각(各各) 차이(差異)가 있으나 G+U/A+C는 3자간(者間)에 1.3의 거이 동일(同一)한 수치(數値)를 보여주고 있다. G+C/A+U는 잠체(蠶體)와 용체에 있어서 동일(同一)하나 견사선(絹絲腺)의 그것과는 차이(差異)가 있다. 한편 잠란(蠶卵)에 있어서는 Pu/Py, G+C/A+U, G+U/A+C가 각각(各各) 잠체(蠶體), 용체 및 견사선(絹絲腺)에 있어서와 현저(顯著)한 차이(差異)를 보여주고 있다. G+C/A+U가 1.3이나 되는 RNA의 base ratio를 가진 생물(生物)에 관(關)해서는 아직 보고(報告)된 바 없고 다만 본논문(本論文)의 가잠(家蠶)에 관(關)한 RNA와 속편(續編)인 각종(各種) 패류(貝類) RNA의 nucleotide 조성(組成)에서 모두 1.3에 가까운 수치(數値)를 보여주고 있다. 3) 견사선(絹絲腺)(후부(後部)) t-RNA와 거미 방적선(紡績腺)의 t-RNA의 nucleotide molar ratio 및 견사선(絹絲腺)의 r-RNA, s-RNA nucleotide 조성(組成)은 다음과 같다. 재료(材料) $\frac{G+C}{A+U}$ $\frac{G+U}{A+C}$ $\frac{Pu}{Py}$ 가잠견사선(家蠶絹絲腺)(후부(後部)의 t-RNA 1.05 1.32 1.15의 r-RNA 1.12 1.30 1.20의 s-RNA 1.55 1.33 0.65 지주방적선(蜘蛛紡績腺)의 t-RNA 1.35 1.24 1.16 즉(卽) 가잠견사선(家蠶絹絲腺)(후부(後部))과 거미방적선(紡績腺)의 t-RNA nucleotide 조성(組成)은 Pu/Py가 1.15와 1.16으로서 거이 동일(同一)하지만 G+C/A+U, G+U/A+C에 차이(差異)가 있음을 보았다. 한편 가잠견사선(家蠶絹絲腺)(후부(後部)) r-RNA와 s-RNA의 Pu/Py와 G+C/A+U는 현저(顯著)한 차이(差異)가 있고, G+U/A+C에 있어서는 1.3으로서 거이 동일(同一)한 수치(數値)를 보여주고 있다. 4. 이상(以上)과 같이 잠체(蠶體)에 관(關)한 RNA의 nucleotide 조성(組成)은 소위(所謂) GC-type로서, 현재(現在)까지 문헌(文獻)에 보고(報告)된 각종(各種) 생물(生物)의 RNA의 base ratio에 관(關)하여 비교(比較) 검토(檢討)하였으며, RNA의 nucleotide ratio의 차이(差異)의 의의(意義)에 대(對)하여 고찰(考察)하였다.

• Parasites, Hosts and Diseases
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• v.25 no.1
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• pp.69-82
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• 1987

The prevalences of the cuke belonging to genus Metagonimus hove been reported along the upper stream of inhabitants by several workers since 1980, however the taxonomical problems of the fluke was not yet settled. The larval flukes; cercaria and metacercaria as well as their intermediate hosts, and adult were studied in order to identify the Mepagonimus in the areas. The results obtained are summarized as follows: 1. The snails, Semisulcospira globus were collected (rom the three different localities along the upper stream of the River. The cercariae were found from 125(7.2%) out of 1,730 snails by natural emerging method, and were identified into 5 species including Metagenimus sp. (3.7%), Pseudexorchis major(1.4%), Cercaria nipponensis (0.9%), Cercaria incerpa(0.6%), and Cercaria yoshidae(0.6%). Cercariae of Metagonimus species had four to dye oral spines on its anterior of the first line. 2. The cercariae of Metagonimus were experimentally exposed to goldfish. nfection rate was 22.9% out of 105 goldfish, and the encysted metacercariae were found in fins(86.7%) and on scales (13.7%) of the fishes, but not in their muscle, head or visceral organs. 3. Seven species of ask were caught in the Daecheong Reservoir and the upper stream. Infestations with metacercaria of Metagonimus were found 100% in Opsariichtys widens and the parasitized numbers of the metacercariae were observed from 250 to 2,400 per fish. In the upper stream, Zacco termmincki, Z. platypus and Pseudogobio esocinus were infected 100% with the metacercaria, on the other hand, the fishes caught in the reservoir showed the lower infestation rates, and a few metacercariae found in the fishes Carassius carassius and Cyprinus carpio in the reservoir and the stream. The majority of metacercariae was detected only on the scales of fishes. 4. In order to know the infectivity and the distribution patterns in the intestine of hosts, rats and dogs were infected with the metacercariae obtained from O. bidens and Z. platypus. In addition the metacercariae obtained from Z. temmincki, P. esocinus and goldfish were given to the rats. The recovery rates of the worms in the small intestine of dogs were higher (63.3~65.8%) than those of the rats (3.5~31.6%). The flukes were found mostly in the middle and the lower part of small intestine of the rats and the dogs, but no worm was collected in the upper part of the intestine of rats. 5. The sixte of adult flukes varied by the hosts. In the adult cukes, oral sucker was smaller than ventral sucker, and the right and left testes were located diagonally, the uterine tubules circled around the upper left testis. The average egg sixte was $29.1{\times}1.7{\mu\textrm{m}}$. According to the above results, the cukes belonging to genus Metagonimus distributed along the Geum River was concluded to be identical with Miyata type of M. yokogawai as that Saito had proposed.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.532-537
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• 2011

'Seolgaeng' is a new Japonica rice variety developed from an 'Ilpumbyeo' mutant line, N-methyl-N-nitrosourea (MNU) treatment on fertilized egg cell, by a rice breeding team of National Crop Experiment Station, Rural Development Administration in 2001. This variety has about 134 days of growth duration from transplanting to harvesting in central plain area of Korea, a good semi-elect plant type and resistant to lodging with strong culm. The number of panicles/hill of 'Seolgaeng' is more than that of 'Hwaseongbyeo'. The milled rice appearance of this cultivar is an opaque, but it has amylose content (19.3%) similar to 'Hwaseongbyeo'. It is superior to hypae formation of Aspergillus orzyae in the making of fermented rice and amount of pigmentation in fermented rice by Monascus anka that of 'Ilpumbyeo'. This variety showed slow leaf senescence and considerable resistance to viviparous germination. It is moderately resistant to leaf blast and susceptible to bacterial blight, virus disease and insect pests. The yield performance of this rice cultivar is about 5.27 MT/ha in milled rice in local adaptability test for three years from 1999 to 2001). 'Seolgaeng' is adaptable to central and southern plain areas of Korea.

• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.206-211
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• 1983

This study was carried out to compare the feed utilization between pelleted and all-mash diet of similar composition by growing chickens. Day-old broilers (Hubbard) and egg-type chickens(Hy-line) of commercial strain were employed in this experiment. The results obtained were summarized as follows. 1. The chickens fed pelleted diets were heavier than those of birds fed all-mash diets. The Hubbard broilers and Hy-line chickens fed pelleted diets weighed 2,702g and 812g respectively, at 9 weeks of age. In comparison, the Hubbard broilers and Hy-line chickens fed all-mash diets weighed 2,571g and 777g respectively, at 9 weeks of age. 2. The pellet-fed chickens consumed more feeds than birds fed all-mash diets in both types of strain. Feed efficiencies (gain/feed) of Hubbard and Hy-line chickens were 0.38 and 0.26 in pellet feeding groups, and 0.36 and 0.25 in all-mash feeding groups, respectively. The Hy-line chickens fed pelleted diets drank more water than birds fed all-mash diets. 3. Pellet feeding groups produced more dry matter excreta as compared with all-mash feeding groups, reflecting the pattern of feed consumption by these chickens. Nitrogen retention ratio of the Hubbard and Hy-line chickens were 57-67% and 65-73%, respectively. Chickens fed pelleted diets showed 1-4% higher nitrogen retention than chickens fed all-mash diets. 4. The ME/GE ratio of the Hubbard and the Hy-line at 8 weeks of age were 73.4-74.3% and 82.8-83.8%, respectively. Pellet feeding groups showed 1% higher ME/GE ratio than all-mash feeding groups. 5. The dietary productive energy calculated from respiratory quotient was $94.1-102.6kca/kg^{\frac{3}{4}}$ BW/day in pellet feeding groups. The ratios of PE/GE were 41.3-48.9% in pellet feeding groups and 39.0-45.8% in all-mash feeding groups. 6. It appears that pelleting the all-mash diet increases feed consumption and body weight gain of growing chickens. Feed efficiency and energy utilization were also improved by pelleting process. More research work should be done to establish the relationship clearly between feed pelleting and heat increments.