• Journal of Nutrition and Health
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• v.26 no.3
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• pp.231-247
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• 1993

This study was designed to confirm the effect of dietary protein level and oral administration of tryptophan on brain serotonin metabolism. Two animal experiments were conducted. The objectives and results of research were as follows : In the first experiment, it was investigated whether administration of reserpine to Sprague-Dawley rats fed 6% or 20% casein diet induced decrease in serum tryptophan and large neutral amino acid(LNAA) concentrations, tryptophan/LNAA concentration ratio, brain tryptophan, serotonin and 5-hydroxyindoleacetic acid(5-HIAA) contents. Brain serotonin content of 6% casein diet group was lower than those of 20% casein diet group. Both 6% and 20% casein diet groups administered with reserpine to induce the analogous depression, showed the notable decrease in brain serotonin content when they were compared with 20% casein diet group not administered with reserpine. Serum tryptophan/LNAA ration and brain 5-HIAA content showed a tendency similar to the change of serotonin content, but the mean difference among all groups was not significant. From these results, it could be said that when the dietary protein level was low, brain serotonin content was decrease. The second experimnt was to see the change in serum tryptophan concentration and tryptophan/LNAA ratio and brain tryptophan, serotonin and 5-HIAA content when tryptophan was administered orally to the animals treated with reserpine. Serum tryptophan concentration tended to increase in both reserpine-treated 6% and 20% casein diet groups administered with tryptophan, especially in the 6% casein diet group. Serum tryptophan/LNAA concentration ratio tended to incrase in reserpine-tteated 6% casein diet group, while decrease in reserpine-treated 20% casein diet group. Brain tryptophan content was increased in both reserpine-treated 6% and 20% casein diet groups. However, brain serotonin content of reserpine-treated 6% casein diet group showed a tendency to decrease, while that of reserpine-treated 20% casein group increase. Consequently, the effect of tryptophan administration on increase of brain tryptophan and serotonin content in animals treated with reserpine was far more excellent in 20% casein diet groups. It was concluded that dietary protein intake and tryptophan administration increase brain serotonin level. Accordingly, it was possible to confirm that brain function, particularly in aspect of behavior related to the serotonin, was changed with manipulation of dietary composition.

• The Korean Journal of Food And Nutrition
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• v.11 no.6
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• pp.647-686
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• 1998

The purpose of this study was to investigate selected nutrient intakes, dietary atherogenesity, energy balance and activity level of college students. One hundred and thirty onoe students (61 males and 70 females) made their three-day dietary records and one-day activity records along with one-day dietary records. BMI of the surveyed students was 22.33 for males and 20.28 for females. Average calorie intakes of male and female students was respectively 2166.20kcal and 1793.60kcal. Females had slightly higher fiber intakes than males in terms of fiber g/1000kcal. Carbohydrate, protein and fat ratios in energy composition of males and females were respectively 56.62 : 15.33 : 24.70 and 57.64 : 16.49 : 25.79. Average cholesterol intakes of male and female students were 295.66mg and 259mg respectively. The male showed higher saturated fat intake. and had higher atherogenic indices of diets such as cholesterol index(CI) and cholesterol-saturated fat index(CSI) than the female. Males spent an average of 1039.00 kcal/day compared to females of 687.93 kcal/day for all physical activities. Most students participated in light (100% of males and females) and moderate (33% of males and 3% of females) activities level. Few students spent time at severe and very severe activity level. Seventeen of the 131 students were in positive energy balance whereas 83% were in negative balance. Both genders with positive energy balance tended towards smaller weight and BMI, and larger food intakes than those with negative energy balance. Students with positive energy balance had higher saturated fat intakes and dietary atherogenic scores of CI and CSI than the counterparts with negative energy balance. Males with positive energy balance had decreased physical activity and daily energy expenditure whereas increased food and saturated fat intakes. Females with positive energy balance had singificantly increased food, saturated fat and sugar intakes.

• Journal of Nutrition and Health
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• v.27 no.10
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• pp.967-978
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• 1994

This study was done to investigate the effect of age and dietary linolenic acid content and the linolenic acid/linoleic acid(LNA/LA) ratio on the lipid metabolism and formation of PGI2 and TXA2. The male Sprague-Dawley rats were fed 6 different with 0.2, 0.4, 0.6 of LNA/LA ratio within either 8% LNA(high LNA) or 4% LNA(low LNA) of fatty acid content for different feeding period(1, 4, 12 month). The dietary fat used were sesame oil, perilla oil, soybean oil and beef tallow. The concentration of serum total lipid, total cholesterol and HDL-C were increased with aging. Triglyceride concentration was decreased in 0.2 ratio of LNA/LA. The lipid content of liver showed similar tendency to that of serum. The ratio of PGI2/TXA2 was increased in 1 month rats and antithrombotic effect was reduced significantly with increasing age. The PGI2/TXA2 ratio was tended to be higher in diet of 0.2 and 0.4 LNA/LA ratio at high LNA level and in diet of 0.6 LNA/LA ratio at low LNA level. Especially PGI2/TXA2 ratio was increased linearly with rising LNA/LA ratio at low LNA level. It seemed that the LNA content and LNA/LA ratio had interaction to increase the antithrombotic effect bychanging TXA2 synthesis. And the dietary fatty acid related effect lowering the serum and liver lipid content, excepting triglyceride, was increased when dietary n3/n6 ratio was high(0.6) at both high and low n3 level. Therefore, it could not be recommended to consume large amount of n3 fatty acid or high ratio of n3/n6 to prevent cardiovascular diseases. These results suggested that the dietary fatty acid ratio of n3/n6 could be determined based on the n-3 content of dietary fat to reduce the risk of cardiovascular disease.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.4
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• pp.371-376
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• 2013

A feeding trial was conducted to determine the optimum dietary protein and lipid levels for the growth of juvenile muddy loach Misgurnus anguillicaudatus. Eight experimental diets (designated as P20L7, P20L14, P30L7, P30L14, P40L7, P40L14, P50L7 and P50L14) were formulated to contain 20%, 30%, 40% and 50% protein with 7% and 14% lipid. Three replicate groups of muddy loach (1.5 g/fish) were fed one of the experimental diets ad libitum for 8 weeks. Survival of fish fed the P20L14 diet was lower than in other groups (P<0.05). Specific growth rate (SGR) and feed efficiency (FE) of fish were affected by dietary protein (P<0.05) and lipid (P<0.005) levels. SGR and FE of fish tended to decrease with increasing dietary lipid level at the same protein level. There were no significant differences in SGR and FE among fish fed diets containing different protein levels ranging from 30% to 50% with the same lipid level. Whole body moisture and lipid contents were affected by dietary protein and lipid levels. Crude lipid content of fish fed the 14% lipid diets was higher than that of fish fed 7% lipid diets at each protein level. The results of this study indicate that a diet containing 30% protein with 7% lipid would be suitable for the optimum growth and effective feed utilization of juvenile muddy loach.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.12
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• pp.1737-1741
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• 2006

The aim of this study was to provide basic information to allow improved nutritional management for velvet production by investigating the effects of dietary protein levels on dry matter intake and production and chemical composition of velvet antler in spotted deer (Cervus nippon). Twenty-four spotted deer stags were assigned to 4 unreplicated groups, Control (15% CP in diet, higher dry matter), CP10 (10% CP), CP15 (15% CP) and CP20 (20% CP). The velvet antlers were harvested from each stag on the 55th day after casting of the buttons from the previous set, measured for their size and weight, and the chemical composition of each antler was determined in three sections (top, middle, and base). Dry matter (DMI) and crude protein (CPI) intake were highest (p<0.05) for the Control and increased progressively (p<0.05) with increasing dietary protein level. Although not significant, mean length and girth of the main antler beam tended to be larger in either left or right beam with increasing protein level in the diet, longest in CP20 and shortest in CP10. Velvet antler production was lowest in CP10 and highest in CP20, which differed significantly (p<0.05). Only negligible differences were found between groups in chemical composition. It is concluded that dietary protein clearly influenced dry matter intake and velvet antler production, whereas there was comparatively little effect of dietary protein on chemical composition of antler in spotted deer.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1241-1245
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• 2004

Two separate trials were conducted to determine effects of dietary level of whole flaxseed (WFS; 0, 10 and 15%) on feed intake, weight gain, and carcass yield and quality of Korean Hanwoo cattle. The daily gains of bulls (Trial 1) were not different among treatment groups, but those of cows (Trial 2) fed WFS 15% were higher (p<0.01) than others. Feed intake of both bulls and cows tended to decrease as dietary level of WFS increased. However, feed conversion ratio (feed/gain) of bulls tended to be improved by dietary inclusion of WFS and was significantly improved (p<0.01) in cows by increasing level of WFS. Neither carcass weight nor dressing percentage were affected by WFS level. Back fat thickness of bulls was decreased (p<0.01) by dietary inclusion of WFS and the same trend was observed in cows without statistical significance. Loin-eye area of bulls was not different among treatment groups but was significantly higher (p<0.01) in cows fed WFS. Carcass yield and quality were not improved by WFS addition. The results indicate that WFS is an acceptable fat source in diets of finishing beef cattle to increase energy density without any adverse effects.

• Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.311-315
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• 2011

A 7-week feeding trial was conducted to investigate the effect of dietary starch level and kind on the growth and body composition of juvenile olive flounder. Triplicate groups of fish (average weight: 1.5 g) were fed iso-nitrogenous (48% crude protein) and isocaloric (4.8 kcal/g diet) diets containing 15-25% ${\alpha}$-potato starch and 15% ${\beta}$-potato starch. Survival was not affected by dietary starch level and kind. The weight gain of fish fed the diet containing 20% ${\alpha}$-potato starch was significantly higher than that of fish fed the diets containing 15% and 25% ${\alpha}$-potato starch levels. The feed efficiency and protein efficiency ratios of fish fed the diets containing 15% ${\beta}$-potato starch were significantly lower than those of the other groups (P < 0.05). The protein efficiency ratio tended to increase with increasing ${\alpha}$-potato starch. The daily feed intake of fish fed the diet containing 15% ${\beta}$-potato starch was significantly higher than that of the other groups (P < 0.05). The hepatosomatic index, condition factor, and proximate composition of the whole body were not affected by the dietary starch level and kind. These results indicate that up to 20% ${\alpha}$-potato starch could be incorporated into the juvenile flounder diet for optimum growth.

• Journal of Nutrition and Health
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• v.50 no.6
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• pp.578-584
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• 2017

Purpose: Excess intake of sodium is a major diet-related risk factor for human diseases including hypertension and cancer as well as obesity and inflammation. However, findings are still controversial, and evidence is lacking in Koreans. Therefore, for better understanding of the role of dietary sodium intake in disease etiology, this study investigated the effects of dietary sodium intake on adiposity, inflammation, and hormones in Koreans. Methods: A total of 80 males and females joined the study. The general characteristics and dietary intake data were investigated by trained interviewers using a questionnaire and 24-h dietary recall, respectively. For the markers of adiposity, body weight, body mass index, percent of body fat, visceral fat area, and waist and hip circumference were measured. For the inflammation and hormone markers, leptin, adiponectin, insulin, tumor necrosis $factor-{\alpha}$, and interleukin-6 were also analyzed. Results: Multivariate linear regression analyses suggested that dietary sodium intake was not associated with adiposity. However, dietary sodium showed a significant association with insulin level: Plasma insulin concentration increased with sodium intake independent of other dietary intake or percent of body fat (${\beta}=0.296$, adjusted $r^2=0.276$, p < 0.01). Other markers for inflammation and hormonal responses were not associated with dietary sodium intake. Conclusion: Findings suggested that dietary sodium intake may be a critical modifying factor in the level of plasma insulin. However, it showed a limited effect on obesity and other inflammation markers and hormone levels. These findings should be confirmed in larger, well-designed investigations.

• Korean Journal of Community Nutrition
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• v.20 no.5
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• pp.327-337
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• 2015

Objectives: Dietary life is closely associated with dietary attitude and diet-related knowledge. Particularly, dietary habit such as sodium intake can be affected by various dietary behaviors such as food choices, dietary attitude toward salty food and a preference for salty taste. The purpose of this study was to assess sodium-related nutrition knowledge and to identify sodium-related attitude and behaviors according to the level of sodium-related knowledge of university students. Methods: Anthropometric measurements were provided by 408 students who participated in this study. The study participants answered questionnaires to provide information on general dietary behaviors, sodium-related dietary attitude and other behavioral factors. A total score of nutrition knowledge was used to categorize study participants in to two groups, namely, low level in sodium-related knowledge (LNaK) or high level in sodium-related knowledge (HNaK) and the attitude and the behaviors of students toward sodium intake were compared between these two groups. Results: The ratio of female students in HNaK group was higher than that in the LNaK group. HNaK group had a higher score in checking nutrition label of processed food than the LNaK group. Total score of sodium-related attitude and behaviors of HNaK group were 34.81 and 32.75, respectively and these scores were significantly higher than that of the LNaK group whose scores were 32.57 and 30.57, respectively. Total energy intake was not different between two groups but the intakes of calcium, vitamin B2 and folate were higher in HNaK group than in the LNaK group. Correlation analysis adjusted for age and gender revealed that total score of sodium-related nutrition knowledge was positively correlated with total score of sodium-related attitude and behaviors. Conclusions: In conclusion, students who had high level of sodium-related nutrition knowledge had desirable attitude and behaviors toward sodium intake and these results can be considered in nutrition education for university students.

• Journal of Animal Science and Technology
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• v.58 no.10
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• pp.37.1-37.10
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• 2016

Background: Providing of insufficient nutrients limits the potential growth of pig, while feeding of excessive nutrients increases the economic loss and causes environment pollution. For these reasons, phase feeding had been introduced in swine farm for improving animal production. This experiment was conducted to evaluate the effects of dietary energy levels and phase feeding by protein levels on growth performance, blood profiles and carcass characteristics in growing-finishing pigs. Methods: A total of 128 growing pigs ([Yorkshire ${\times}$ Landrace] ${\times}$ Duroc), averaging $26.62{\pm}3.07kg$ body weight, were assigned in a $2{\times}4$ factorial arrangement with 4 pigs per pen. The first factor was two dietary energy level (3,265 kcal of ME/kg or 3,365 kcal of ME/kg), and the second factor was four different levels of dietary protein by phase feeding (1growing(G)-2finishing(F) phases, 2G-2F phases, 2G-3F phases and 2G-3F phases with low CP requirement). Results: In feeding trial, there was no significant difference in growth performance. The BUN concentration was decreased as dietary protein level decreased in 6 week and blood creatinine was increased in 13 week when pigs were fed diets with different dietary energy level. The digestibility of crude fat was improved as dietary energy levels increased and excretion of urinary nitrogen was reduced when low protein diet was provided. Chemical compositions of longissimus muscle were not affected by dietary treatments. In backfat thickness ($P_2$) at 13 week, pigs fed high energy diet had thicker backfat thickness (P = 0.06) and pigs fed low protein diet showed the trend of backfat thinness reduction (P = 0.09). In addition, water holding capacity was decreased (P = 0.01) and cooking loss was increased (P = 0.07) as dietary protein level reduced. When pigs were fed high energy diet with low subdivision of phase feeding, days to 120 kg market weight was reached earlier compared to other treatments. Conclusion: Feeding the low energy diet and subdivision of growing-finishing phase by dietary protein levels had no significant effect on growth performance and carcass characteristics. Also, phase feeding with low energy and low protein diet had no negative effects on growth performance, carcass characteristics but economical profits was improved.