• Parasites, Hosts and Diseases
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• v.26 no.1
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• pp.9-14
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• 1988

In an attempt to determine the susceptibility of inbred golden hamsters(Mesocricetus auratus) to the experimental infection with Clonorchis sinensis, twenty-five hamsters were divided into 5 groups and administered orally 5, 10, 20, 30 or 50 metacercariae each. The hamsters were killed on the 45th day after infection. The adult flukes were recovered from all hamsters. The overall recovery rate for the fluke was 57.9% with the range of 48.4% to 92.0%. As the number of the metacercariae given increased, a porportionate decrease in the recovery rate was found, the prepatent period of the fluke in the hamster varied from 15 to 17 days, with the average of 16 days. No significant differences in the development of the flukes were observed. Egg production expressed by EPG, increased step by step as the time elapsed. However, a tendency of decreasing egg laying capacity was observed with the increase of worm burden. It is suggested that the hamster is a suitable final host of C. sinensis.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.243-248
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• 2003

This paper is contents on that construct ultra high speed wireless communication cell backbone net of city using of wireless communication transceiver for millimeter wave band. A new type of 60GHz wave band wireless transceiver using NRD waveguide. This 60GHz transceiver has excellent signal's absorption characteristics of oxygen molecule than the other millimeter wave bands. We constructed service networks to cell interval within about 500m to 3Km laying stress on wireless backbone node using 60GHz transceivers, and did it so that city type wireless communication cell backbone networks of 155.52Mbps ATM(OC-3) may be possible. The possible use of wireless backbone networks technology in a rainy day and a clear day was evaluated at 1Km data link distance. We can measured bit error rate(BER). BER is $10^{-11}$ at 155.52Mbps ATM(OC-3) in a clear day and $10^{-6}$ in a heavy rain more than 35mm per time. Also, we constructed wireless cell backbone networks distance to use several 60GHz transceivers and investigated data transmission rate between main center and local center of long distance. In proposed wireless cell backbone networks, the data throughput was approximately 80Mbit/sec. Therefore, if use transceiver, it is possible that city type ultra high speed wireless communication cell backbone networks construction of 100Mbps, 155.52Mbps, 622Mbps, 1Gbps and 1.2Gbps degrees.

• Korean Journal of Poultry Science
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• v.16 no.3
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• pp.175-192
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• 1989

A total of 9, 012 cases was submitted for diagnosis of chicken diseases to Veterinary Research Institute, Rural Development Administration from domestic chicken farms during 18 years from 1971 to 1988. Of them, 6, 181 cases diagnosed as the infectious disease were investigated for the detection rate of infections on basis of you, season , and chicken age. The results obtained were summarized as followings：1. Detection rate or the infections was lowest as 49.3% in the year 1973, and highest as 78.6% in 1985 (average 68.6%). 2. Of infections detected, bacterial diseases were most frequent (32.6%), and followed in order by viral (26.3%), parasitic (7.7%), and fungal diseases (2.1%) in geneal. 3. The most frequently detected bacterial diseases in order of prevalence were mycoplasmosis (8.8%), colibacillosis (8.5%), and staphylococcosis (5.8%), and followed by salmonellosis pullorum disease , yolk sac disease, and salpingitis (0.8-1.5%). 4. In viral diseases, 7.5% of infections detected was lymphoid leukosis and 7.2%-Marek's disease, 4.4%-Newcastle disease, 2.0%-infectious laryngotracheitis, 1.7%-infectious bursal disease, and 1.0%-avian encephalomyelitis, while detection rate of infectious bronchitis, egg drop syndrome '76, and inclusion body hepatitis was less than 1.0%, respectively. 5. The most prevalent parasitic disease was coccidiosis (4.5%), followed by ascariasis (1.4%). The detection rate of other parasitic diseases including leucocytozoonosis, black head , heterakiasis, and ectoparasitosis was very as 0.2-0.7%, respectively： In fungal diseases, 2.0% of infections was detected as aspergillosis, and followed by candidiasis (0.1%). 6. Detection rate of the infections on basis of season was somewhat higher in summer. (27.7%), and autumn (27.7%) than in winter (23.5%), and spring (21.5%) in general. In bacterial, viral, and fungal diseases, there were the similar tendencies of detection rate as in infections, while parasitic diseases were much highly detected in summer (34.3%), and autumn (39.5%) than in any other season. 7. Among bacterial diseases colibacillosis was most frequently detected in summer, and staphylococcosis in autumn. In detection rate of viral diseases, Marek's disease, infectious laryngotracheitis, and infectious bursal disease was highest in summer, lymphold leukosis, fowl pox and egg drop syndrome '76 in autumn, and infectious trachitis in winter, repectively. The majority of important parasitic diseases including coccidiosis were highly detected in summer and autumn. 8. On basis of chicken age, detection rate of infections were highest in chicken of growing period between 30 and 150 days of age (41.4%), and followed by 35.3% in laying chicken over 150 days of age, and 17.3% in chicken of brooding age under 30 days of age. Bacterial, and parasitic diseases were most frequently detected in chicken of growing period, viral diseases in chicken of growing, and laying period as nearly equal rate of detection, and fungal diseases in chicken of brooding age.

• Korean Journal of Poultry Science
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• v.29 no.3
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• pp.151-156
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• 2002

The objective of this study was to compare the two different eggshell lines of commercial layers on egg traits and egg production rate. Hy-line W-98 (white shell line; WSL) and Hy-line Brown (brown shell line; BSL) were used as experimental stocks. The birds in each line were allocated to three floor pens each containing 25-birds. They were fed a ration containing 15.5% CP and 2,700 ㎉/kg ME, and were supplied 16 h of light per day throughout the experimental Periods. The egg traits and egg Production rate were measured from 53 to 56-wk-old and 20 to 56-wk-old, respectively. The mean egg weight and the mean percentage albumen were significantly heavier and higher (P<0.05) in the BSL than in the WSL, respectively. The mean eggshell thickness and the mean percentage shell were also significantly thicker and higher (P<0.05) in the BSL than those in the WSL, respectively. However, the mean percentage yolk and the yolk to albumen ratio showed a reverse trend as shown in the mean percentage albumen or percentage eggshell. Although the WSL birds started laying 4 d earlier than the BSL ones, the overall mean egg Production rate for BSL during 20 to 56 wk of age was significantly higher (P<0.05) by 6.6% than the WSL. It was concluded that the eggs of brown eggshell line had heavier egg weight and thicker shell, and they had more percentage of albumen, but less percentage of yolk than those of the white eggshell line. These results suggest that the brown eggshell line raised on the floor might be more beneficial than the white eggshell line not only for the preference of the table egg consumers, but also for the efficient production of the eggs.

• Korean journal of applied entomology
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• v.56 no.2
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• pp.97-105
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• 2017

An investigation was conducted to determine the characteristics of seasonal occurrences and effective insecticides for minimizing the occurrence of Pseudaulacaspis cockerelli in sweet persimmon orchards. Most of the nymphs or female scales that mated in mid-September overwintered on twigs, matured to lay eggs in the next spring in accordance with temperature increase, and survived till mid to late May to lay all of their eggs. Males mostly died after mating by the end of September, while the males on the fallen leaves died during the hibernating period. Egg laying in P. cockerelli showed differences in accordance with the weather conditions in each year. They laid eggs from mid-April to mid- or late May, with a peak in early or mid-May. A female was estimated to lay 160 eggs; eggs hatched a week later from the peak period of egg laying. In summer, egg laying started in early or mid-July and ended in mid- or late August, with a peak in late July or early August; a female laid approximately 130 eggs in summer. The estimated egg period was 4 days. The first generation nymph that hatched from the eggs laid by the overwintered female on twigs showed 10% occurrence on twigs and 90% on leaves. The first generation nymphs on twigs mostly developed into female scales. The occurrence of the second generation nymphs reached a peak on July 27, 2009; they lived on the twigs as their overwintering site from mid- or late August. The female and male scales on leaves developed at the similar rate as the first generation nymphs up to August. The occurrence of male scales indicated that the peak occurrence of nymphs was on August 12, 2009, male scales on August 27, and adults approximately on September 14, which showed steady relationship in the sequence of development from nymphs to adult males. Among the nymphs that occurred on the leaves on August 12, 75% of them emerged into male adults, mated, and died. Buprofezine+dinotefurn (20+15) WP treatment on June 9 and 16 resulted in 90.6% control of P. cockerelli, when mortality was checked 7 weeks after treatment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.614-620
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• 2004

This study was to determine the effect of dietary $\beta$-cyclodextrin ($\beta$CD) on egg quality and cholesterol content of egg yolk. One-hundred 28-week-old laying hens were randomly distributed into five groups of twenty hens each and maintained in individual laying cages for 10 weeks of the experiment. They were assigned to the five treatments of experimental layer diets containing 0, 3, 5, 7 or 10% pure $\beta$CD of diets. Food intake, egg production and egg weight varied slightly and insignificantly in the hens fed with 0, 3, 5 or 7% $\beta$CD-added diets. But food intake, egg production, and egg weight were uniformly lower (p＜0.05) in the hens fed with 10% $\beta$CD-added diets. Food conversion rate, when expressed per number egg, was impaired (p＜0.05) without having an obvious relation to the dietary $\beta$CD level. No difference in haugh unit, egg yolk color, and egg shell thickness was found among treatment. The cholesterol content of egg yolks was significantly decreased (p＜0.05) to 3.76, 5.12, 5.49 and 6.48 mg/g yolk in $\beta$CD 3, 5, 7 and 10% treatments respectively when compared to that of the $\beta$CD 0% group. The cholesterol content of eggs, when expressed in mg/60 g egg, was greatly (p＜0.05) decreased to 54, 71, 77 and 86 mg in $\beta$CD 3, 5, 7 and 10% treatments when compared to that of the $\beta$CD 0% group. The most striking effects (p＜0.05) were observed in $\beta$CD 5% and 7% treatments, whose cholesterol content decreased from 28.19% to 30.23%. In conclusion, $\beta$CD added-diets fed to laying hens can reduced the cholesterol content of egg yolk, and this new type of egg yolk with lower cholesterol can be considered a functional livestock food.

• Korean Journal of Poultry Science
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• v.33 no.4
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• pp.283-293
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• 2006

Two experiments were conducted to investigate the effects of dietary activated charcoal mixed with wood vinegar (AC) on broiler performance and antibiotics residue in eggs. In experiment 1, a total of low hundred fifty, 1-day-old male broile. chicks (Ross) were divided into 6 groups, consisting 3 replicates of 25 birds each, and 134 one of the six experimental diets: devoid of AC and antibiotics (negative control), devoid of AC with 0.1% antibiotics (positive control), devoid of antibiotics with 1% AC, with 0.1% antibiotics and 1% AC, devoid of antibiotics with 2% AC, with 0.1% antibiotics and 2% AC, for 5 wks. Feed consumption and body weights were measured weekly. At the end of the experiment, eight birds from each group were selected and sacrificed. The relative weight of organs and characteristics of breast muscle were investigated. There were no significant differences in feed intake, body weight gain and feed conversion rate among the treatments. There were also no significant differences in the relative weight of breast meat, leg and liver. The abdominal fat tended to be decreased by the dietary AC. Significant differences were shown (P<0.05) in meat redness (a) and yellowness (b) among the treatments. However, the sensual characteristics of breast muscle was not affected by the dietary treatments. There were significant differences in total microbes, Coli forms and lactic acid bacteria (P<0.05) among the treatments. In experiment 2, a total of ninety, 40-wk-old Hy-line Brown laying hens were divided into 3 groups, consisting 3 replicates of 10 birds each and fed medicated control diet devoid of AC or diets containing 1% AC and 2% AC for 2 wks. The residue of antibiotics in Plasma and egg Yolk were significantly decreased (P<0.05) in 2% AC group compared to that of control. This study suggest that dietary AC may improve the external quality of edible meat and reduced antibiotics residue in chicken eggs without affecting laying performance.

• Korean Journal of Poultry Science
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• v.32 no.3
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• pp.211-217
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• 2005

This study was carried out to investigate the effects of Saccharomyces cerevisiae (wild yeast mutant), Saccharomyces cerevisiae hFeHLC (ferritin containgig yeast) and chelated Fe diets on the Productivity and egg qualify of laying hens. A total of 245 'Brown Tetra' layers 35 weeks aged was randomly alloted to seven dietary treatments : 1) control diet no iron added, 2) diet supplemented $0.1\%$ wild yeast mutant (YM03), 3) diet supplemented $1.0\%$ wild yeast mutant (YM03), 4) diet supplemented $0.1\%$ ferritin with yeast (YF04), 5) diet supplemented $1.0\%$ ferritin with yeast (YF04), 6) diet supplemented $0.01\%$ chelated Fe and 7) diet supplemented $0.1\%$ chelated Fe. The egg Production rate was significantly increased in layers 134 Fe supplemented diets (p<0.05). Egg weight was significantly reduced in layers fed $0.1\%$ chelated Fe diet (P<0.05). Fe content of egg yolk was significantly increased in $1.0\%$ YF04 and $0.1\%$ chelated Fe treatments (P<0.05). There were no significant differences in shape index, albumin index and yolk index of eggs of layers fed diets Fe supplementation (P>0.05). The haugh unit of eggs was significantly increased in layers fed YM03, YF04 and chelated Fe supplemented diets (p<0.05). TBA value of egg was significantly increased in different iron Fe treatments except of $0.1\%$ YM03 (P<0.05). The yolk cole. of eggs was significantly increased in $1.0\%$ YF04 diet (P<0.05).

• Applied Biological Chemistry
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• v.20 no.2
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• pp.205-209
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• 1977

The pool size of plasma glucose, turnover rate and other concerned items for glucose metabolism in normal laying hen were investigated by a single-injection method using $U-C^{14}-glucose$. The 11.6 nCi of pure dose was injected to a hen normally fed through the wing vein. The glucose concentration in plasma sample taken at 5 minutes after injections was 214mgper 100ml. From the plottings of logarithmic standard specific activities of plasma taken from 5 to 120 minutes against the time after injection and from the regresion analysis, metabolic states were determined. The pool size was 1.07g, turnover rate was 0.024 per minute, turnover time was 41 minutes, utilization rate was 26mg/min. (0.83 g/hr/kg B.W. 3/4) and glucose space(extracellular fluid volume) was 25.3 per cent of body weight. The values obtained from. 10-50 minutes samples were similar to those described above, which we from 5-120 minutes samples.

• Microbiology and Biotechnology Letters
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• v.38 no.4
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• pp.391-398
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• 2010

This study was conducted to investigate the effects of feeding probiotics(gene modified yeast) on the egg quality in laying hens. The laboratory method of this study is as follow: In hens, 300, 36 weeks old ISA brown commercial layer, were employed in 13weeks feeding trial with a 7 days adjustment period. Dietary treatments are 1) control (basal diet) 2) Y0.3 (basal diet+0.3% probiotics), 3) Y0.5% (basal diet+0.5% probiotics), 4) PY0.3% (basal diet+0.3% plasmid modified probiotics), 5) PY0.5% (basal diet+0.5% plasmid modified probiotics). For overall period, hen-day egg production, egg weight (p<0.05) by dietary probiotic supplementation were recorded. Eggs were collected and weighed every day. Egg production number and egg production rate, egg weight, failure egg ratio and trouble egg ratio were recorded for 13weeks days. Diets PY0.3 and PY0.5 improved Egg production rate, egg production number and egg weight, compared to control diet (linear effect. p<0.05). And, diets PY0.3 and PY0.5 improved Egg production rate, egg production number, compared to Y0.3 and Y0.5 (linear effect. p<0.05). But, in Inferior egg and cracked egg, diets PY0.3 and PY0.5 did not tended to increase by dietary probiotic supplementation compared to control diet and Y group (0.3, 0.5) (linear effect. p<0.05). The productivity enhance on the egg quality in laying hens is considered from the effects of feeding probiotics(gene modified yeast).