• Fisheries and Aquatic Sciences
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• 제19권5호
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• pp.24.1-24.6
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• 2016

We determined the optimum dietary protein level in juvenile barred knifejaw Oplegnathus fasciatus in cages. Five semi-purified isocaloric diets were formulated with white fish meal and casein-based diets to contain 35, 40, 45, 50, and 60 % crude protein (CP). Fish with an initial body weight of $7.1{\pm}0.06g$ ($mean{\pm}SD$) were randomly distributed into 15 net cages (each size: $60cm{\times}40cm{\times}90cm$, $W{\times}L{\times}H$) as groups of 20 fish in triplicates. The fish were fed at apparent satiation level twice a day. After 8 weeks of feeding, the weight gain (WG) of fish fed 45, 50, and 60 % CP diets were significantly higher than those of fish fed 35 and 40 % CP diets. However, there were no significant differences in WG among fish fed 45, 50, and 60 % CP diets. Generally, feed efficiency (FE) and specific growth rate (SGR) showed a similar trend as WG. However, the protein efficiency ratio (PER) was inversely related to dietary protein levels. Energy retention efficiency increased with the increase of dietary protein levels by protein sparing from non-protein energy sources. Blood hematocrit content was not affected by dietary protein levels. However, a significantly lower amount of hemoglobin was found in fish fed 35 % CP than in fish fed 40, 45, 50, and 60 % CP diets. Fish fed 60 % CP showed the lowest survival rate than the fish fed 35, 40, 45, and 50 % CP diets. Broken-line analysis of WG showed the optimum dietary protein level was 45.2 % with 18.8 kJ/g diet for juvenile barred knifejaw. This study has potential implication for the successful cage culture of barred knifejaw.

• Journal of Nutrition and Health
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• 제22권4호
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• pp.223-236
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• 1989

To evaluate the differences of the levels and sources of protein intake human protein metabolism, an 26-day metabolic balance study was conducted in 10 healthy Korean adult females. In the pre-study, the subjects recorded their own diets for 3 days. The metabolic balance study consisted of 6-day adaptation period, 10-day moderate protein period(60-65g/d) and 10-day high protein period(90-95g/d). During the moderate and high protein period, 5 subjects were fed the higher animal protein meals and the other 5 subjects were fed the high plant protein meals. Body weight, nitrogen balance and blood chemistries were monitored through out the study. The urine volume were sighificantly larger in the animal protein group and, the dietary fiber and fecal weights were significantly heavier in the plant protein diet group. But no statistically significant differences were found between the two dietary groups in apparent nitrogen digestability, urinary nitrogen excretion and nitrogen balance. Body weight, serum protein, albumin and HDL-cholesterol levels were not changed, but serum total cholesterol level in the animal protein diet group was elevated significantly from 143.8mg/dl on moderate potein diet to 173.0mg/dl on high proetin diet. In conclusion, from the observation of this short-term N balance study, plant diet on the adequate level of calorie and protein intake had almost the same effect of animal protein diet for protein maintenace in adults.

• 한국가금학회지
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• 제14권2호
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• pp.125-135
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• 1987

본 시험은 산란계사료의 에너지 및 단백질 수준이 하절기에 있어서 갈색 산란계의 생산성에 미치는 영향을 구명하기 위하여 대사에너지 3수준(2,500, 2700 및 2900Kcal/kg)과 단백질 3수준(13, 15 및 17%)을 조합한 9개처리에 24주령된 Warren 산란계 720수를 공시하여 1983년 6월 3일부터 동년 8월 25일까지 12주간에 걸쳐 시험을 실시한 바 그 결과는 다음 요약과 같다. 1. 산란율은 에너지 수준이 증가할수록 점차 저하되었고 단백질 수준이 증가할수록 점차 증가하였다. 2. 란중은 에너지 수준에 따라서 큰 차이가 없었으나 단백질 수준이 증가할수록 증가하였다. 3. 사료섭취량은 에너지 수준이 증가할수록 점차 감소하였으나, 단백질 수준에 따라서는 차이가 없었다. 4. 사료요구율은 단백질 수준이 증가할수록 점차 개선되었다. 5. 폐사율은 사료중의 에너지 및 단백질 수준에 영향을 받지 않았다. 6. 1일수당 에너지 섭취량은 사료중의 에너지 수준이 증가할수록 점차 증가하였다. 7. 산란 kg당 대사에너지 요구량은 에너지 수준이 증가할수록 점차 증가하였으며 단백질 수준이 증가할수록 감소하였다. 8. 산란kg당 단백질 요구량은 에너지 및 단백질수준이 증가할수록 점차 증가하였다. 9. 산란kg당 사료비는 에너지 수준이 증가할수록 점차 증가하였고 단백질 수준이 증가할수록 점차 감소하였다.

• 한국가금학회지
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• 제21권4호
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• pp.267-275
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• 1994

Three dietary ME levels of 3,200, 2,900 and 2,600 kcal /kg in the same 13% single-stage low protein diet were compared to evaluate the effect of ME levels of grower diets on egg-type pullet growth and subsequent laying performance. As the ME levels of grower diets decreased, cumulative feed and protein consumptions increased(P<0.05), however, the ME intake and body weight at 18 wk of age decreased(P<0.05). Grower feed cost decreased as the dietary ME level was decreased, but no significant difference was found among dietary ME levels of grower diets. During the laying period, sexual maturity, hen-day egg production and average egg weight were not significantly affected by the ME levels of grower diet, however, daily feed intake and feed required per egg decreased as the dietary ME level of grower diet was reduced(P<0.05). Results of this study indicate that pullets can be reared on the low ME diet of 2,600 kcal /kg and it would he economical to utilize the low energy diet during the growing period when they are reared on a 13% single-stage low protein diet.

• Asian-Australasian Journal of Animal Sciences
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• 제17권3호
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• pp.386-393
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• 2004

This study was conducted to investigate the effects of feeding dried leftover food (DLF) on growth, body composition and feed conversion of broiler chicks. One hundred ninety-six of one-day old Ross broiler chicks were assigned to 7 treatments in a completely randomized design. Each treatment had four replications with seven chicks per replication. The treatments groups included control without DLF, dietary 10% level of DLF, dietary 20% level of DLF and dietary 30% level of DLF, 5% higher protein level of diet containing 10% DLF, 10% higher protein level of diet containing 20% DLF and 15% higher protein level of diet containing 30% DLF than control diet. Body weight gain was slightly higher in control group than that of DLF-fed groups. However, there were no significant differences in body weight gain among those groups fed diets containing different levels of DLF. In general, increasing dietary level of DLF resulted in decreasing feed conversion. Content of crude protein in whole broiler body was slightly higher in control group although any significant difference was not found among treatments (p>0.05). Content of crude fat in whole broiler body was lowest in groups fed diets containing 30% DLF with 15% higher protein level than control diet, showing significant difference from groups fed diets containing 20% DLF (p<0.05). Contents of total cholesterol, free cholesterol, cholesterol ester and LDL- cholesterol in blood of broilers fed DLF-containing diets generally appeared to be higher compared with control group without significant difference (p>0.05). Fatty acid contents in broiler meat were higher in the order of oleic acid, palmitic acid and linoleic acid without significant differences among treatments. Content of DHA in broiler meat was higher in groups fed diets containing DLF than that of control group although there were no significant differences among treatments (p>0.05).

• Preventive Nutrition and Food Science
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• 제7권3호
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• pp.278-281
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• 2002

The objective of the current study was to determine the influences of dietary proteins and methionine on plasma lipid concentrations. Thirty growing male Sprague-Dawley rats were fed diets similar in all respects except that dietary protein was from either casein, soy protein isolate, or soy protein isolate supplemented with L-methionine (0.24 %). The animals were fed experimental diets ad libitum for nine weeks. Plasma total-cholesterol concentrations were unaffected by the protein source or methionine supplementation. Plasma triglyceride concentrations were lower in rats of methionine supplemented soy protein diets (76 mg/dL) than in the rats fed casein or soy diet (120 mg/dL, 109 mg/dL, respectively). These results indicate that soy protein reduces plasma triglycerides relative to casein in rats fed cholesterol free diets, and that methionine-supplemented soy diets decrease plasma triglyceride concentrations more than soy protein alone.

• Journal of Nutrition and Health
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• 제26권8호
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• pp.915-924
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• 1993

To study the effect of menopause and dietary protein level on Ca metabolism, ovariectomy (OVAX) and sham operations were performed in 16-week old female rats. Each treatment group was fed for 16 weeks either 5%(L) or 50%(H) casein diets, forming SH, SL, OH, OL groups. High protein groups(SH, OH) showed higher Ca and hydroxyproline excretion in urine. Urinay hydroxyproline was also higher in OVAX, which tells the possibility of increased bone resorption by OVAX and by high dietary protein. At 16th wee, however, urinary Ca and hydroxyproline of SH caught up with OH group, whereas those of OL remained higher than SL. Therefore it seems that high dietary protein overrides the effect of OVAX with time. Urnary protein measured at 8th week was higher in high protein groups, especially in OH. GFR was not differ significantly among groups at 8th week. At 16th week, however, high protein groups showed twice the GFR value of low protein groups. Therefore the increase of urinary Ca and hydroxyproline in SH and OH groups can be explained partly by the increased GFR. The tendency of increased GFR and urinary excretion of protein, Ca, and hydroxyproline was most obvious in OH group. It seems that the effect of high protein diet is likely to accelerated by ovariectomy. The effect of Ovax and dietary protein on the composition of femur, scapular, and lumbar bones, was not pronounced. However, when only the high protein groups were compared, OVAX resulted in the reduction of bone weight, ash and Ca contents, especially in femur. The reason that was no significant effect on bone might be due to the short experimental period to induce that was no significant effect on bone might be due to the short experimental period to induce the changes on bone composition and dietary Ca content used in this experiment may have been high enough to prevent bone loss.

• 한국양식학회:학술대회논문집
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• 한국양식학회 2003년도 추계학술발표대회 논문요약집
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• pp.17-18
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• 2003

Although flounder is one of the most important marine fish for aquaculture in Korea, feeding the flounder in commercial farms depends mainly on moist pellet in which over 70% frozen fishes (e.g. frozen horse mackerel) are incorporated in its formulation. Therefore, for further expansion of flounder farming, it is essential to employ practical formulated feeds that can support reasonable growth. Development of nutritionally balanced and cost-effective feeds is dependant on the information about nutritional requirement and feed utilization of the species. Nutrient and energy source in feed are needed for the growth and maintenance of fish. Protein is probably the most important nutrient affecting fish growth and feed cost. Therefore, it is essential to determine the optimum dietary protein level for the growth of fish, both its high proportion in the feed and because it is the main factor in determining feed cost. Dietary energy level is also critical because protein source in the feed is utilized as an energy source when the feed deficient in energy is fed to fish, whereas when the feed excess in energy is fed to fish, feed consumption decreased and resulted in growth reduction due to lack of other necessary nutrients for normal growth. Improper dietary protein, energy levels and/or their ratio will lead to an increase of fish production cost and deterioration of water quality resulting from wasted feed; thus, they are important in formulating commercial feed. Dietary lipids play important roles in providing energy and essential fatty acid for normal growth and survival of fish. Although carbohydrates are not essential nutrients for carnivorous fish, these compounds play important roles as a low-cost energy source for protein sparing and also as a feed binder. Nutrition researches for flounder have identified its requirements of protein, lipid and essential fatty acid, vitamin, and minerals for normal growth. Other studies have also been carried out to investigate the utilization of the protein, lipid and carbohydrate sources. Based on these nutritional information obtained, practical feed formulations have been studied for improve aquaculture production of flounder. The results of the researches on utilization of dietary protein, lipid and carbohydrate by flounder are discussed in this review.

• Journal of Nutrition and Health
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• 제39권2호
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• pp.145-159
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• 2006

This study was performed to investigate the stress level, dietary attitudes and nutrient intakes of Food and Nutrition major female students at a university located in Changwon. A total of 122 female students taking the course 'Meal Management' during 2001-2004 participated in this study. The general characteristics, stress level and dietary attitudes of the subjects were surveyed using a self-administered questionnaire. The nutrient intake data collected from 3-day food-record method were analyzed by the Computer Aided Nutritional Analysis Program. The symptoms by stress showed that 'eye strain', 'physically exhausted or get tired' and 'pains on neck or shoulders' were high in 59.4-81.8%. The mean scores of stress in 2001-2004 were 8.5-12.0 out of 30 points and the subjects in 2002 and 2004 scored significantly higher on stress level than the subjects in 2001 did (p < 0.00. The mean scores of dietary attitudes were 58.7-66.6 out of 100 points, most of the subjects are belonged to the 'fair' group in terms of dietary habits level. The stress level had a negative correlation with dietary habits (p < 0.001). About 1/3 of the subjects, the intake of calcium, vitamin $B_2$, vitamin A and iron were less than 75% of Korean RDA, whereas more than half of the subject, protein, vitamin C and phosphorus intake were more than 125% of RDA, and intake ratio of Ca and P showed an unbalance of 1 : 2. The animal protein intake was higher than the plant protein, whereas the animal vitamin A and iron intake were lower than vegetable food source. In 2001-2004, the index of nutritional quality (INQ) of vitamin $B_2$ and niacin was 0.56-0.98, and in 2003, the INQs of vitamin $B_2$ was 0.56, and that of niacin was 0.67, which was extremely low when compared to that of the other nutrients. Therefore, nutritional education is necessary if female university students are to practice optimal nutrition, including well-balanced diets of high nutritional quality.

• Asian-Australasian Journal of Animal Sciences
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• 제30권3호
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• pp.386-391
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• 2017

Objective: Protein supplementation is costly and can result in excess nitrogen (N) excretion. The objective of this study was to evaluate the effects of feeding different levels of dietary protein on average daily gain, body size, rumen fermentation, and nitrogen excretion of 8 to 10 month-old Holstein heifers. Methods: Thirty-six Holstein heifers were divided into 12 blocks according to age ($273{\pm}6.2d$) and were randomly assigned to diets containing a low (10.2% dry matter [DM]), medium (11.9% DM), or high (13.5% DM) level of dietary crude protein (CP). All diets contained approximately 70% roughage and 30% concentrate with similar dietary metabolizable energy (ME) content (2.47 Mcal/kg). Results: Dry matter intake did not differ among the treatments, and average daily gain increased with the increasing dietary protein, 0.79, 0.95, 0.97 kg/d for low, medium, and high group, respectively. Body height increased linearly with increasing dietary CP but no other significant differences in body dimensions were found among the treatments. The increased ratios of dietary CP improved the rate of rear teat length growth remarkably (p<0.05). There was no difference in rumen pH or ruminal major volatile fatty acid (acetate, propionate, and butyrate) concentration among the 3 diets, but rumen ammonia-N concentration increased with the higher dietary CP (p<0.05). Increasing N intake led to increased total N excretion; urinary N excretion was significantly increased (p<0.05) but fecal N excretion was similar among the treatments. Conclusion: These data suggest that the diet containing 11.9% CP (ME 2.47 Mcal/kg) could meet the maintenance and growth requirements of 9 to 11 month-old Holstein heifers gaining approximately 0.9 kg/d.