• Korean Journal of Poultry Science
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• v.50 no.1
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• pp.15-22
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• 2023

This study was to investigate the relationship between chick weight in the growing period and the laying performance of Korean native chicken (KNC) breeders. We measured the body weights of 1,384 KNC breeders at 1-140 days of age at two-week intervals. The age at first egg laying, hen-day and hen-housed egg production, and the egg weights were investigated. Correlation coefficients between the body weight and egg production traits were analyzed. The results showed that the correlation coefficients between body weight and age at first egg laying were significantly positive before 4 weeks, but negative after 8 weeks of age. The correlation coefficients between body weight and egg production rate were estimated to be negative before 8 weeks and positive after 12 weeks of age. Coefficients of hen-day and hen-housed egg production were similar. There was little correlation between body weight and egg weight at 32 weeks of age, whereas a low positive correlation was with egg weight at 50 weeks. In conclusion, there was little correlation between body weight and laying performance before 8 weeks of age, whereas a significant positive correlation was with body weight after 12 weeks. The results suggest that as the chick's weight increases in the late growing stage, sexual maturity is faster, the egg production rate is higher, and the egg weight increases. Therefore, the weight management of KNC female breeders is very important in the late growing stage, and the body weight of chicks must be maintained above the standard weight.

• Biomedical Science Letters
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• v.7 no.1
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• pp.39-45
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• 2001

The findings of serum biochemical tests in the inhabitants residing in some riverside areas of kyongsangnam-do were analized to know the correlation with the Clonorchis sinensis infection. A total of 2,722 fecal samples of inhabitants was examined by Kato's cellophane thick smear and formalin-ether sedimentation methods, and their serums were analized biochemically. Three hundred and thirty-three inhabitants (12.2%) were positive with C. sinensis eggs (egg-positive group), and remaining 2,389 were negative (egg-negative group). In the egg-positive group, the positive .ate of aspartate aminotransferase (AST) was 6.9% (male: 10.3%; female: 3.2%), that of alanine aminotransferase (ALT) was 6.3% (male: 9.1%; female: 3.2%), of $\gamma$-glutamy1 transpeptidase ($\gamma$-GIP) was 9.0% (male: 13.1%; female: 4.4%), and that of $\alpha$-fetoprotein (AEP) was 3.0% (male: 2.9%; female: 3.2%). In the egg-negative group, the positive rate of AST was 5.2% (male: 8.9%; female: 3.2%), that of ALT was 5.1% (male: 8.6%; female: 3.2%), of $\gamma$-GTP was 7.5% (male: 13.0%; female: 4.5%), and that of AFP was 0.3% (male: 0.5%; female: 0.1%). In the egg-positive group, 127 cases (38.1%) were light infection, 108 (32.4%) were moderate infection,64 (19.2%) were heavy infection, and 34 (10.2%) were very heavy infection. The positive rates of all tests were high according to the intensity of infection. From the above results, It was confirmed that prevalence of clonorchiasis is still high in some riverside areas of Kyongsangnam-do, and findings of serum biochemical tests are not different between the egg-positive group and egg-negative group. However, there were some difference in the positive rates of serum AST, ALT, $\gamma$-GTP and AEP by the age, sex and the intensity of infection.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.8
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• pp.1164-1170
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• 2008

In this study, the effects of propolis and vitamin C (L-ascorbic acid) supplementation in diets were investigated on feed intake (FI), body weight (BW), body weight gain (BWG), feed conversion rate (FCR) and digestibility and on egg production and qualities (weight, mortality, shell thickness) in laying hens exposed to heat stress. A total of 150 Hyline White Leghorn, aged 42 weeks, hens was divided into five groups of 30 hens. Chicks were randomly divided into 1 positive control, 1 control and 3 treatment groups. The chicks were kept in cages in temperature-controlled rooms at $22^{\circ}C$ for 24 h/d (positive control, Thermoneutral, TN group) or $34^{\circ}C$ for 9 h/d from 08.00-17.00 h followed by $22^{\circ}C$ for 15 h (control, heat stress, HS group) and fed a basal diet or basal diet supplemented with vitamin C (250 mg/kg of L- ascorbic acid/kg of diet) or two levels of propolis (2 and 5 g of ethanol extracted propolis/kg of diet). Increased FI (p<0.05) and improvement in FCR (p<0.05), hen day egg (p<0.05) and egg weight (p<0.05) were found in Vitamin C and propolis-supplemented laying hens reared under heat stress conditions. Mortality rate was higher in the control group than TN, vitamin C and propolis groups (p<0.05). Digestibility of dry matter, organic matter, crude protein and ether extract improved with increasing of both dietary vitamin C and propolis (p<0.05). Vitamin C or propolis supplementation did not affect either the percentage shape index, yolk index or haugh unit and albumen index (p>0.05). However, the egg shell thickness and egg shell weight appeared to be increased in Vitamin C and propolis groups in comparison to HS group birds (p<0.05). In conclusion, dietary supplementation of laying hens with anti-oxidants (vitamin C and propolis) can attenuate heat stress-induced oxidative damage. These positive effects were evidenced by increased growth performance and digestibility, improvement of egg shell thickness and egg weight in comparison to non-supplemented birds. Moreover, supplementation with propolis (5 g/kg diet) was the most efficient treatment.

• Parasites, Hosts and Diseases
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• v.35 no.4
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• pp.265-270
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• 1997

To assess several chemotherapeutic schemes for control of enterobiasis, 738 children in five primary schools in Chunchon, Korea, were studied from May 1994 to June 1995. They were divided into 6 groups by the schemes: treatment of once or hice a year; treatment of positive cases or of whole class students; treatment with or without family members. The overall egg Positive rate before intervention was 17.5% out of 789 children. Treating all individuals in a class together with family members of positive cases brought better control efficacy than other schemes (P=0.000). However, when egg Positive rate is less than 30%, treating only egg Positive cases also can reduce egg Positive rate. The con- founding factors for the enterobiasis control in primary schoolchildren were new-comer to a class and familial infection.

• Parasites, Hosts and Diseases
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• v.58 no.5
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• pp.527-535
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• 2020

To clarify the reinfection profile associated with risk factors of opisthorchiasis, we conducted an epidemiological study on the chemotherapeutic effects on reinfection with O. viverrini in the endemic areas of Northeastern Thailand for 3 years. A total of 3,674 fecal samples were collected from participants in villages of 5 provinces. They were examined microscopically using a modified technique of formalin ethyl-acetate concentration. Egg-positive residents were reexamined year (2018) by year (2019) after treatment with a single dose (40 mg/kg) of praziquantel. Health education was provided to the participants yearly. The egg-positive rate of O. viverrini was 14.3%, and was highest (22.2%) in the 20-30 year-old group in 2017. The egg positive rate was 15.3% in dogs and 11.4% cats. Human reinfection rate was 15.5% and 6.3% in next 2 years, and was highest (23.2%) among the fishermen. Relative risk factors of reinfection were significantly higher for males, over 40-year-old age, or working as fishermen or farmers, and eating uncooked fish within the preceding year. A significant difference resulting from a health education program was observed in the third year. Therefore, health education and sustainable surveillance for opisthorchiasis should be maintained to decrease the risk of reinfection.

• Parasites, Hosts and Diseases
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• v.25 no.2
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• pp.181-184
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• 1987

The cello·tape anal swab specimens from 936 primary school children in Seoul, 308 primary school children in a rural area and 92 children in Nanjido, were examined for Enterobius vermicularis eggs. Out of 936 specimens from a primary school in Seoul, E. vermicularis eggs were detected in 114 specimens, the egg detection rate being 12.2%. In 308 specimens from a primary school in a rural area,77 (25.0%) were positive for 5. vermicularis eggs. Among 92 specimens from Nanjido children in Seoul, egg Positive rate of E. vermicularis was 28.3%. The egg detection rate of primary school children in Seoul was significantly lower than that of primary school children in a rural area and of Nanjido children. The egg detection rate in boys was lower than that of girls. As the age of children increased, the egg detection rate decreased.

• Korean Journal of Health Education and Promotion
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• v.27 no.3
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• pp.49-57
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• 2010

Objectives: This study was conducted to investigate the occurrence and possible risk factors of enterobiasis among children in kindergartens. Methods: A total of 3,921 children were examined from 36 kindergartens in Ulsan, Korea. The parents were asked to complete questionnaires and to detect Enterobius vermicularis infection using the anal swab technique. Results: The overall rate of being positive for E. vermicularis egg was 7.8% ranged from 0 to 29.0%. The infection rate was related to age, gender, thumb sucking, pre-medication of anthelmintics, employment status of mother and number of siblings. The risk factors significantly associated with E. vermicularis infection were gender(OR 1.628), thumb sucking(OR 1.643), pre-medication of anthelmintics(OR 0.614), employment status of mother(OR 0.574) and number of siblings(OR 0.388). Conclusion: We propose that E. vermicularis infection screening among children in kindergartens should be continued on a regular basis. In addition, more intensive control program should be developed and applied to children.

• Journal of agricultural medicine and community health
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• v.13 no.1
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• pp.26-31
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• 1988

An epidemiological study was undertaken to evaluate the prevalence of E. vermicularis infestation among children in primary schools and orphanages. A total of 2,966 children in primary schools and orphanages was examined for F. vermicularis by means of cellotape anal swab technique. The purpose of the present studies is to determine the prevalence of enterobiasis among children and to make a comparison with the rate of infestation by survey areas. The result could be summarized as follows : 1) The egg positive rate of cellotape anal swab method was 16.3% out of 2,966 children. 2) The egg positive rate of urban area was 6.9% out of 1,144 children and the egg positive rate of rural area was significantly higher than that of urban area. 3) The egg positive rate of boys and girls were 15.7% out of 1,528 children and 16.9% out of 1,438 children. 4) The egg positive rate of primary schools, orphanages and mental retardation child group was 11.3% (out of 2,412), 32.7% (out of 416) and 55.1% (out of 138) respectively. There was noted a tendency of decrease in prevalence by increase of the age.

• Journal of agricultural medicine and community health
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• v.25 no.2
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• pp.303-314
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• 2000

In order to evaluate prevalence and perception on the intestinal trematodes of inhabitants at Docho-island, Shinan-gun, Chollanam-do, a questionnaire survey for the epidemiological study and stool examination for the detection of the eggs of the trematodes were done on 224 individuals at the island from January to February, 2000. The results were as follows: 1. Egg positive rate of the intestinal trematodes was 21.0%. 2. The egg positive rate has revealed significantly higher in the elderly over age 70 than other ages, higher in seashore villagers than inland ones, and higher in persons who had a rural and/or marine ph than persons with other jobs, respectively(P<0.05). 3. The egg positive rate of alcoholic drinkers was higher than non-alcoholic persons, and the rate was also higher in smokers than non-smokers. It was statistically significant(P<0.05). 4. The egg positive rate was shown to be significantly higher in inhabitants who ate raw mullet that was well known to be the source of infection with the intestinal trematodes than people who did not eat the raw marine fishes(P<0.01). 5. The egg positive rate was also significantly higher in humans who had the complaints of frequent abdominal pain and diarrhea than healthy people(P<0.05). In conclusion, the prevalence of intestinal trematodes at the island located in the south and west area in Korea was too high to eradicate the parasitic infections. So a special program is necessary for the control of the trematode infections in many adjacent islands at Chollanamdo.

• Parasites, Hosts and Diseases
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• v.29 no.3
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• pp.235-244
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• 1991

An epidemiological study and mass treatments of Enterobius vermicularis infection among children near Wonju area of Kangwon province were carried out. The children were divided into 4 groups according to their residing localities; children in the mountainous area, rural area, urban area and in orphanage. They were examined by adhesive cellotape anal swab technique, and egg positive rates were obtained. The rates of egg reduction and re-infection rates after repeated mass treatments were also observed. The results obtained were as follows: 1. The overall egg Positive rate of E. vermicularis in the first screening was 19.9% (251 out of 1, 262 examinees; 19.7% in males and 20.1% in females). The positive rates were 13.0% in the mountainous area, 11 9% in the rural area, 15.1% in the urban (medium-sized) area and 61.9% in orphanages. 2. The highest positive rates were observed in the kindergarten children, and 1st and 2nd grade children of primary schools (26.2~32.2%), and the lowest rate (13.6%) in 6-year grade children of primary schools. 3. Cumulative detection rates from 3 repeated anal swabs at 4~5 days interval were higher (70.8%) than those from single anal swabs (50.0~59.2%). 4. Out of the examinees who showed the highest cumulative positive rate (70.8%), about 39.2% were consecutively positive in 3 anal swabs. Among different groups of children, the higher the total egg detection rates (87.5%), the higher the consecutive positive rates (71.9%) . 5. A total of 2, 609 (male : female=1 : 12.4) worms were collected from 17 egg-positive cases treated with anthelinintics. The mean number of worms per child was 153 (range: 4-824) . 6. The egg-positive cases in several studied groups (180 children) were treated with anthelmintics 6 times at 3-week intervals. In this case, the overall positive rate was decreased from 54.8% to 2.2% at 15 weeks after the treatments, but no complete negative conversion was experienced. However, in a group of children (154 children) including egg Positive and negative cases who were both treated with anthelmintics at 3-week interval, a complete egg-negative conversion was observed in the 9th week after treatments. 7. The egg-detection rate in the brothers or sisters of egg Positive children was 70.0% (28 out of 40 examined), and the egg-positive rate according to the family unit was 69.7%. In summarizing the above results, it is concluded that Enterobius vermicularis infection is still highly prevalent among children in Korea, and that repeated mass treatments of more than 3 times will be effective for control of this infection.