• 농업과학연구
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• 제45권4호
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• pp.687-694
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• 2018

This study was conducted to investigate the laying performance of six strains of Korean domestic chickens (KDC 1A, 2A, 3A, 1B, 2B and 3B). A total of 288 20-week-old KDC hens were allocated in a completely randomized design to give 12 replicates per each strain (4 chickens per pen). The chickens were fed commercial diets (i.e., week 20 - 32, crude protein [CP] 18.0% and metabolizable energy [ME] 2,850 kcal/kg; week 32 - 40, CP 17.0% and ME 2,800 kcal/kg) ad libitum together with fresh water during the 20-week experiment. Body weight, age of sexual maturity, egg weight, hen-day egg production (HDP) and feed conversion ratio (FCR) were measured during the experiment period (week 20 - 40). Our results show that strain 3B had an improved (p < 0.05) HDP and FCR compared with the other strains on week 24 - 28. However, strain 3A had an improved (p < 0.05) HDP and FCR compared to the other strains on week 28 - 40. Similarly, strain 3A had a higher egg weight (p < 0.05) compared to the other strains on week 28, 32 and 40. In conclusion, the higher laying performance of strain 3A indicates its potential in the development of a KDC strain with improved commercial laying performance.

• Asian-Australasian Journal of Animal Sciences
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• 제31권6호
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• pp.864-872
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• 2018

Objective: The objective of this study was to determine the effect of weaning age on intake, performance, nutrition metabolism and serum parameters of beef calves. Methods: Sixty Droughtmaster crossbred calves were assigned to 5 groups with 12 calves in each group. The calves in control group remained with the dams till the 22-week age, while the calves weaned at 28 d (4 wk), 42 d (6 wk), 56 d (8 wk), and 70 d (10 wk) of age were sent to group 4 wk, group 6 wk, group 8 wk, and group 10 wk, respectively, and then were fed on milk replacer till the 22-week age. Feed intake and body weight and size were record and blood metabolites were measured. And 24 calves of them (6 in each group) were picked randomly for digestion and metabolism trail. Feed, feces and urine sample were taken and measured. Results: Dry matter intake of calves in group 4 wk was significantly lower than those in the remaining groups from wk 17 to 22 (p<0.05). Feed efficiency of the calves was higher in groups 4 wk and 6 wk than those in groups 8 wk and 10 wk from 11 to 13 wk (p<0.05), and calves had higher feed efficiency in group 4 wk, group 6 wk, and group 8 wk than those in group 10 wk from wk 14 to wk 22. Calves in group 4 wk and 6 wk had lower body weight than group 8 wk and group 10 wk and control group at 10-week age (p<0.05) and 13-week age (p<0.05), and calves in group 6 wk had no significant difference in body weight with control group, group 8 wk and 10 wk (p>0.05) but was higher than that of group 4 wk (p<0.05). Calves in group 6 wk had higher final body weight and total gain than group 4 wk, but no difference of total gain with that of groups 8 wk, 10 wk, and control group. And weaning calves at 6-week age brought higher feed efficiency and average daily gain from wk 14 to wk 22, and higher dry matter and organic matter digestibility at 21 wk. Conclusion: It is concluded that the weaning of calves at 6 weeks of age gave positive results.

• Asian-Australasian Journal of Animal Sciences
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• 제23권3호
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• pp.302-307
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• 2010

The present study aimed to investigate the effects of maternal factors on body weight at hatching (day-old) and at six weeks of age in a commercial broiler line. A total of 6,765 records on body weight at day-old (BWTDO) and 115,421 records on body weight at six weeks of age (BWT6W), originated from a commercial broiler line during 14 generations, were used to estimate genetic parameters related to the effects of maternal traits on body weight of chicks immediately after hatch or six weeks thereafter. The data were analyzed using restricted maximum likelihood procedure (REML) and an animal model with DFREML software. Direct heritability ($h^{2}{_a}$), maternal heritability ($h^{2}{_m}$), and maternal environmental variance as the proportions of phenotypic variance ($c^{2}$) for body weight at day-old were estimated to be 0.050, 0.351, and 0.173, respectively. The respective estimated values for body weight at six weeks of age were 0.340, 0.022, and 0.030. The correlation coefficient between direct and maternal genetic effects for six-week-old body weight was found to be -0.335. Covariance components and genetic correlations were estimated using a bivariate analysis based on the best model determined by a univariate analysis. Between weights at hatching and at six week-old, the values of -0.07, 0.53 and 0.47 were found for the direct additive genetic variance, maternal additive genetic variance and permanent maternal environmental variance, respectively. The estimated correlation between direct additive genetic effect influencing weight at hatch and direct additive maternal effect affecting weight at six weeks of age was -0.21, whereas the correlation value of 0.15 was estimated between direct additive maternal effect influencing weight at hatch and direct additive genetic effect affecting weight at six-week-old. From the present findings, it can be concluded that the maternal additive genetic effect observed for weight at six weeks of age might be a factor transferred from genes influencing weight at hatch to weight at six-week-old.

• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.249-254
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• 1994

An experiment was conducted to investigate the performance and production cost of Pekin ducklings fed varying levels of dietary protein. One hundred and twenty ducklings in four separate groups received either 16, 18, 20 or 22% CP in the starter period (day-old to 3rd week of age). These four groups ate either 12, 14, 16 or 18% CP respectively during the grower-finisher period (4th week to 12th week of age). The results of the study indicated that in a tropical country like Bangladesh, the protein needs of Pekin ducklings should be satisfied depending on the age at which the birds are to be marketed. If the ducklings are to be marketed at 6 weeks, 22/18% CP would be sufficient. When the marketing is aimed at 9 weeks of age, 20/16% would be adequate. For ducklings which are to be marketed at 12 weeks of age, a protein level of 18/14% would be required. All these results should help the producers to keep production cost to a minimum. The exceptional capacity of ducklings for compensatory growth would help keep birds on low protein levels if they are reared upto 9 or 12 weeks before marketing.

• International journal of advanced smart convergence
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• 제12권4호
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• pp.395-406
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• 2023

Ten women in their 20s and 10 women in their 50s were selected to investigate the effect of an elastic band exercise program for 8 weeks according to age on women's knee speed expression rate and balance. Knee isokinetic muscle strength measurement, single-legged standing with eyes closed, and YBT were performed 1 week before and after the exercise program. The measured data were analyzed through a mixed design two-way ANOVA, and if there was a significant difference, post hoc verification was performed using the bonferoni method. In our study, as a result of an 8-week elastic band exercise program, there was no difference in the speed development rate according to the measurement period, and the speed development rate according to age was found to be higher in people in their 50s than in their 20s. In our study, there was no difference in balance ability depending on the measurement period, and there was also no difference in balance ability depending on age. Discussing the results of our study, we found that 8 weeks of elastic band exercise cannot bring about significant changes in speed development ability and balance ability, which become more accurate with age.

• Restorative Dentistry and Endodontics
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• 제10권1호
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• pp.187-191
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• 1984

Vital pulpotomies by conventional method were done in 120 male and female cases between the ages of 20 and 60 who visited to SNUDH. The pulpotomized surfaces were covered by FR paste and clinical symptoms were carefully examined 1 week and 4 weeks later. The results were as follows; 1. There was no distinct difference between male and female as a whole, and pain to cold and hot or percussion was increased by aging. 2. Incidence of pain to cold and hot or percussion in group examined 4 weeks later was slightly increased than in group examined 1 week later. 3. There was no case of pain to cold and hot or percussion over all ages after 1 week, but were 5 cases (male 2, female 3) in 40 age, and were 3 cases (male 1, female 2) in 50 age after 4 weeks. 4. In 20 and 30 age, there was no case of pain to cold and hot or percussion after 4 weeks, also.

• Nutrition Research and Practice
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• 제16권3호
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• pp.379-391
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• 2022

BACKGROUND/OBJECTIVES: We investigated the associations between eating away from home (EAFH) and overweight and obesity among Ugandan adults using the 2014 Uganda non-communicable disease risk factor survey. SUBJECTS/METHODS: In total, 3,025 participants aged 18-69 years were included in the analysis. The frequency of EAFH was assessed by asking participants the number of meals eaten per week that were not prepared at a home. EAFH frequency was categorized as; less than once/week, 1-2 times/week, or ≥ 3 times/week. Logistic regression was used to evaluate the associations between overweight, obesity, and EAFH. We also tested whether sex and age modified these associations. RESULTS: Participants that ate away from home ≥ 3 times/week were 2.13 times more likely to be obese than those that ate away from home less than once/week (odds ratio [OR], 2.13; 95% confidence interval [CI], 1.28-3.54). However, when the analysis was stratified by sex, women that ate away from home ≥ 3 times/week were 42% less likely to be overweight than those that ate away from home less than once/week (OR, 0.58; 95% CI, 0.36-0.94). Men that ate away from home ≥ 3 times a week were 3.89 times and 2.23 times more likely to be obese and overweight, respectively, than those that ate away from home less than once/week (obesity: OR, 3.89; 95% CI, 1.50-10.09; overweight: OR, 2.23; 95% CI, 1.42-3.51). Age-stratified analysis showed that among participants aged 31-50 years, those that ate away from home ≥ 3 times a week were 3.53 times more likely to be obese than those that ate away from home less than once/week (OR, 3.53; 95% CI, 1.69-7.37). CONCLUSIONS: Frequent EAFH was positively associated with overweight and obesity among men, and obesity among young/middle-aged adults, but negatively associated with overweight in women. Nutritional interventions for obesity reduction in Uganda should include strategies aimed at reducing the frequency of eating meals prepared away from home, and specifically target men and young/middle-aged adults.

• 한국가금학회지
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• 제32권2호
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• pp.125-133
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• 2005

한국재래 닭에서 고환 지지세포와 간질세포의 발달유형을 명확하게 이해하기 위하여 부화 후 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, 21, 28, 32, 44, 52 및 64주령(n:13마리/일령)의 한국재래 닭을 이용하여 이 연구를 수행하였다. 한국재래 닭의 고환은 $2.5\%$ glutaraldehyde를 이용하여 전신 관류 고정하고 조직 처리과정을 거쳐 Epon-araldite에 포매하였다. 초박절편기를 사용하여 $1{\mu}m$로 절편한 다음 methylene blue로 염색하여 형태 계측을 하였다. 부화후 1주령의 한국재래 닭 고환의 평균용적은 $0.148\;cm^3$이었고 점진적으로 증가하여 21주령에는 $3.93\;cm^3$이고 21주령부터 64주령까지는 변화가 없었다. 곱슬정세관의 용적 치밀도는 1주령에 $32.6\%$이었으나 점차적으로 증가하여 64주령에서는 92.89이었다. 1주령의 한국재래 닭에서 고환 간질조직은 고환실질의 $67.4\%$를 나타내었고 이러한 비율은 성장하는 동안에 점차적으로 감소하여 64주령에 $7.11\%$를 나타내었다. 간질세포의 용적 치밀도는 1주령부터 14주령까지 단계적으로 감소하였고 이후에는 변화가 관찰되지 않았다. 이와는 다르게 지지세포의 용적 치밀도는 1주령에 $3.4\%$를 차지하고 있었고 점진적으로 증가하여 18주령에 $10.79\%$이었으며 이후에는 변화가 없었다. 고환조직내 지지세포와 간질세포의 절대용적은 일령에 1주령부터 24주령까지는 유의성 있게 증가하였으나 24주령부터 64주령까지는 차이가 없었다. 고환조직당 간질세포의 총 숫자는 1주령부터 21주령까지는 유의성 있게 증가하였으나 그 이후에는 변화가 없었고 지지세포의 숫자는 1주령부터 14주령까지 점진적으로 증가하였고 그 이후의 주령에서는 변화가 없었다.

• 한국식품영양학회지
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• 제30권4호
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• pp.644-652
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• 2017

In this study, we have analyzed the 2015 KNHANES VI to understand the nutritional and health status of Korean middle-age adults from the perspective of frequency of eating breakfast. Those that eat breakfast five to seven times a week were 76.3 percent (male) and 72.7 percent (female). Frequency of eating lunch and dinner, and eating out was significantly higher among male subjects. The higher the frequency of eating breakfast, the higher the frequency of eating lunch, dinner and eating out. Female subjects that ate breakfast five to seven times a week had lower height and weight compared with other groups, but there was no significant difference of BMI and waist circumference among the four groups. Adults that eat breakfast five to seven times a week had consumed more carbohydrates, dietary fiber, phosphorus, potassium and vitamin C regardless of gender, which validates the nutritional benefits of eating meals regularly. Male adults that ate breakfast five to seven times a week revealed lower levels of diastolic blood pressure and LDL-cholesterol compared with other groups, which validates eating breakfast regularly was beneficial to their health. In conclusion, it is necessary to eat regular meals daily relative to the nutritional status and health of Korean middle-age adults.

• Asian-Australasian Journal of Animal Sciences
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• 제24권4호
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• pp.532-539
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• 2011

The objective of this study was to determine age-related changes in the percentage content of edible and non-edible components in broiler chickens. The experimental materials comprised 240 Ross 308 chicks (sex ratio 1:1) raised to 10 weeks of age and fed standard diets ad libitum. Starting from the first week of rearing, every 7 days 10 males and 10 females were selected randomly for slaughter and post-slaughter analysis. The data obtained were verified statistically. The percentage content of edible components increased and the percentage content of non-edible parts decreased as the chicks grew older. In broilers aged 1 week and 10 weeks, edible components accounted for 47.0% and 66.4% total body weight, respectively. The share of muscle tissue increased considerably over this period, from 30.9% total body weight in week 1 to 52.4% in week 10. An increase in the percentage of skin and subcutaneous fat was observed for the first three weeks only, while the percentage content of giblets (in contrast to the remaining edible parts) decreased with age. For non-edible parts, the share of bones diminished by 2.5% and the proportion of slaughter offal reduced by 13.8%. A rising tendency was noted with respect to feathers and abdominal fat, while the content of the remaining offal decreased.