• Asian-Australasian Journal of Animal Sciences
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• 제25권3호
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• pp.369-374
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• 2012

A $3{\times}2$ factorial experiment was conducted to determine the effects of dietary protein and lipid levels on the growth and body composition of juvenile far eastern catfish. Six diets were formulated to contain three levels of protein (20%, 30% and 40%) and two levels of lipid (9% and 17%). Triplicate groups of fish (initial body weight of 7.6 g) were hand-fed to apparent satiation for 66 days. Final mean weight was improved with increasing dietary protein and lipid levels, and the highest final mean weight was observed in fish fed the 40/17 (% protein/% lipid) diet. No significant difference was observed in final mean weight for fish fed between 30/17 diet and 40/9 diet. Feed efficiency of fish fed the diets containing over 30% protein levels with 9% and 17% lipid levels were significantly higher than those of fish fed the 20% protein levels. Feed efficiency of fish fed the 30/17 diet was not significantly different from that of fish fed the 40/9 diet or 40/17 diet. Feed efficiency and protein efficiency ratio of fish fed the 20% protein diets with 17% lipid level were significantly higher than those of fish fed 9% lipid diet. Daily feed intake of fish tended to decrease with increasing dietary protein and lipid levels. Moisture content of whole body in fish fed the 9% lipid diets was significantly higher than that of fish fed the 17% lipid diets at the same protein level, but the opposite trends were found for crude lipid content. Significant effects of dietary lipid were observed for most fatty acids, according to their relative values in the diets. The results of this study suggest that the protein requirement for maximum growth of juvenile far eastern catfish may be higher than 40%, and an increase of dietary lipid level from 9% to 17% can improve growth and feed utilization.

• Asian-Australasian Journal of Animal Sciences
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• 제24권9호
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• pp.1274-1281
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• 2011

Dietary protein restriction affects lipid metabolism in rats. This study was performed to determine the effect of a low protein diet on hepatic lipid metabolism and insulin sensitivity in growing male rats. Growing rats were fed either a control 20% protein diet or an 8% low protein diet. Feeding a low protein diet for four weeks from 8 weeks of age induced a fatty liver. Expression of acetyl-CoA carboxylase, a key lipogenic enzyme, was increased in rats fed a low protein diet. Feeding a low protein diet decreased very low density lipoprotein (VLDL) secretion without statistical significance. Feeding a low protein diet down-regulated protein expression of microsomal triglyceride transfer protein, an important enzyme of VLDL secretion. Feeding a low protein diet increased serum adiponectin levels. We performed glucose tolerance test (GTT) and insulin tolerance test (ITT). Both GTT and ITT were increased in protein-restricted growing rats. Our results demonstrate that dietary protein restriction increases insulin sensitivity and that this could be due to low-protein diet-mediated metabolic adaptation. In addition, increased adiponectin levels may influences insulin sensitivity. In conclusion, dietary protein restriction induces a fatty liver. Both increased lipogenesis and decreased VLDL secretion has contributed to this metabolic changes. In addition, insulin resistance was not associated with fatty liver induced by protein restriction.

• Journal of Nutrition and Health
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• 제27권1호
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• pp.90-99
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• 1994

This study was carried out to examine how dietary protein and calcium levels in rats fed fat-enriched diet affect the total lipid and cholesterol contents of blood and tissues. Male Sprauge-Dawley rats weighing approximately 200g were fed six purified diets which contained 18%(w/w) beef tallow, 1% (w/w) cholesterol, two source of protein, casein or isolated soy protein (ISP) and three levels of dietary calcium, 0.1%, 0.4% and 1.0%, first, for four weeks, and second, for eight weeks. The contents of the total lipid, cholesterol and triglyceride in blood, liver, heart and feces were determined. After four weeks feeding serum lipid and cholesterol concentrations significantly decreased in rats fed 1.0% (w/w) level calcium, regardless of dietrary protein sources. After eight weeks, these concentrations were significantly lower in the rats fed soy protein than in casein-fed rats. As dietary calcium level increased serum and tissue lipid and cholesterol contents were decreased and fecal lipid excretion increased. It is concluded that hypolipidemic and/or hypocholesterolemic effects of soy protein and calcium were partly due to decrease in lipid absorption.

• 한국양식학회지
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• 제21권1호
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• pp.19-25
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• 2008

본 연구는 어린 돌기해삼 Stichopus japonicus 사료의 적정 단백질과 지질 함량을 조사하기 위해 단백질(10%, 20%, 30% 및 40%)과 지질(3%, 7% 및 11%)이 달리 함유된 12 종류의 실험사료를 제조하였다. 평균 체중 1.1 g의 치삼을 각 수조마다 50마리씩 3반복으로 수용하여 8주간 수행하였다. 사육실험 종료 후, 생존율은 86% 이상으로 실험구간에 유의한 차이가 없었다(P>0.05). 증중율과 일간성장율은 동일한 지질함량에서 단백질 30%에 지질 3% 함유 사료 공급구가 다른 실험구에 비해 유의하게 높은 값을 나타내었다(P<0.05). 치삼의 수분, 지질 및 회분 함량은 사료의 단백질과 지질함량에 따른 차이를 보이지 않았으나, 단백질함량은 실험구간에 유의한 차이를 보였으며(P<0.05), 단백질 30%에 지질 3% 함유 사료 공급구에서 가장 높게 나타났고, 단백질 20%에 지질 11% 공급구에서 가장 낮았다. 지방산 조성은 사료의 지방산에 영향을 받아 지질함량이 증가함에 따라 18:2n-6은 증가하였고 n-3HUFA는 감소하는 경향을 보였다. 이상의 결과로부터, 해삼의 최대 성장에 필요한 단백질함량은 30%이고, 지질함량은 3%로 판단된다.

• 한국양식학회지
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• 제12권2호
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• pp.145-153
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• 1999

This study was conducted to determine the protein requirement of ayu (Plecoglossus altivelis). Two replicate groups of fish initially averaging 6.6 g were fed the five isocaloric diets containing different protein level from 29% to 57% in a flow-through freshwater system for 25 days. White fish meal was used as a sole protein source. Weight gain and feed efficiency of fish increased significantly with dietary protein level up to 43% (P＜0.05) with no additional response above this level. Protein and lipid retention, moisture, protein and lipid contents of body were not affected by dietary protein levels (P>0.05). Daily protein intake increased significantly with dietary protein level, whereas protein efficiency ratio of fish fed the 57% dietary protein decreased (P<0.05). The data obtained in this study indicate that a 43% dietary protein level could be recommended for the optimum growth of ayu.

• 한국양식학회지
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• 제11권1호
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• pp.1-10
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• 1998

돌돔 사료의 적정 단백질 및 지질 함량을 구하기 위해 북양어분과 카제인을 단백원으로 하여 사료의 단백질 함량이 30, 40, 50 및 60%가 되도록 하고, 각 단백질 함량에 지질 함량이 8 및 16%가 되는 8종의 실험사료로 평균체중 7 g의 돌돔을 대상으로 8주간 사육 실험하였다. 사료의 단백질 함량에 따른 증체율 및 사료효율은 사료지질 8% 수준에서 사료단백질이 40% 이상인 사료구에서는 사료단백질 함량이 증가함에 따라 유의차 있게 증가하였으며(P<0.05), 사료지질 16% 수준에서는 사료단백질이 증가함에 따라 증가하다가, 사료단백질 50% 이상에서는 유의적인 차이가 없었다(P>0.05). 사료지질 16% 수준에서 broken line model을 이용하여 증체율을 지표로 하여 돌돔의 적정 단백질 요구량을 구한 결과 46%로 추정되었다. 사료의 지질 함량에 따른 증체율은 사료단백질 40 및 50% 수준에서 고지질 사료구(16%)가 유의하게 높았으며, 사료효율은 모든 사료단백질 수준에서 고지질 사료구(16%)가 유의하게 높았다(P<0.05). 단백질 효율 및 단백질 축적율은 모든 사료단백질 수준에서 고지질 사료구가 높았다. 따라서 성장과 사료효율을 기준으로 볼 때 돌돔 사료의 적정 지질 함량은 16% 전후로 추정되었다. 전어체 및 등근육의 성분에서 단백질은 사료의 단백질 함량이 증가함에 따라 증가하다가 사료 단백질 40% 이상에서는 유의차가 없었으며, 지질은 모든 사료단백질 수준에서 고지질 사료구가 높았다. 간 및 내장의 성분에서 단백질은 사료의 단백질 함량에 따라 뚜렷한 경향이 없었지만, 지질은 모든 사료단백질 수준에서 고지질 사료구(16%)가 높았다.

• Journal of Nutrition and Health
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• 제26권8호
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• pp.925-932
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• 1993

To study the effects of dietary protein and magnesium level on serum lipid contents and enzyme activities, male Sprague-Dawley rats were divided into six groups. Six groups of animals were fed six experimental diets different with protein(8% and 20%) and magnesium levels (Mg-free, 400mg/kg diet and 800mg/kg diet). The serum lipid contents and enzyme activities of rats fed different dietary protein and magnesium levels were examined. Serum triglyceride contents was significantly decreased as the dietary magnesium level was increased. Serum phospholipid contents was significantly higher in magnesium deficient group than those in the other groups. Serum alkaline phosphatase activity was significantly decreased in magnesium dificient group compared with other groups, but serum glutamic oxaloacetic transaminase and glutamic pyruvic transaminase activities was significantly increased in magnesium dificient group than other groups. In conclusion, serum triglyceride contents in low protein level was remarkably decreased as the dietary magnesium level was increased.

• 한국농촌생활과학회지
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• 제6권1호
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• pp.31-39
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• 1995

This study was performed to observe how soy protein and calcium in rats fed unsaturated fat-enriched diet affect the total lipid and cholesterol contents of blood and tissues male Sprague-Dawley rats weighing approximately 220g were fed four purified diets which contained 18% (w/w) corn oil, 1% (w/w) cholesterol, two sources of protein : casein or isolated soy protein (ISP) and two levels of dietary calcium : 0.1% or 1.0%, first for four weeks (Expt. 1) and second for eight weeks (Expt. 2). The contents of total lipid, cholesterol and triglyceride in blood, liver, heart and feces were determined. After four weeks feeding, the serum lipid and cholesterol concentration was not significantly different among the groups. After eight weeks feeding, these concentrations were significantly lower in ISP-High calcium group. The serum lipid concentration was influenced by dietary protein sources and calcium levels. These results indicated that the hypolipidemic effects of soy protein and high calcium intake were partly due to decrease in lipid absorption and these effects were not detected at 4 weeks feeding but 8 weeks feeding.

• Asian-Australasian Journal of Animal Sciences
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• 제19권2호
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• pp.236-244
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• 2006

This study was designed to determine the effects of daidzein (DE) on hepatic lipid metabolism in chicks fed with low protein (LP) diet based on casein. In experiment 1, the male chicks were fed with one of the three levels of dietary protein containing 10.95%, 21.9% and 43.8% protein content for 2 days. In experiment 2, the chicks were fed one of the three levels of protein with or without DE at 1,000 mg/kg diet for 2 days. Experiment 3 was conducted to compare DE (LP+DE) with estradiol (LP+E2) in chicks fed with LP diet for 7 days. Plasma lipid profiles, hepatic lipid profiles, activities of hepatic malic enzyme and isocitrate dehydrogenase (ICDH) were measured. Transcriptions of hepatic fatty acid synthase, apolipoprotein-B (APO-B), and fructose bisphosphatase mRNA were measured by RT-PCR. Increasing dietary protein levels markedly decreased the concentrations of plasma triglycerides, hepatic total lipids, hepatic TG, and the mRNA transcriptions while the increased dietary protein levels increased hepatic ICDH activities in experiment 1. In experiment 2, the effects of dietary protein levels on blood and hepatic lipid content were more prominent than those of the additional DE. Interestingly, plasma TG levels were affected by DE supplementation (p<0.05). In experiment 3, DE inhibited APO-B mRNA expressions and stimulated the accumulation of lipid in the liver through mechanisms different from E2. In this study, we demonstrate that DE has beneficial effects on blood lipid profiles, but that it inhibits APO-B mRNA transcription and aggravates the fatty liver induced by LP diet in chicks.

• Asian-Australasian Journal of Animal Sciences
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• 제24권3호
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• pp.407-413
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• 2011

Effect of dietary protein and lipid levels on compensatory growth of juvenile olive flounder (Paralichthys olivaceus) was determined in suboptimal temperature ($13.4{\pm}1.42^{\circ}C$). Five hundred forty fish averaging 79.2 g were randomly distributed into 27 of 300 L flow-through tanks (20 fish/tank). Nine treatments were prepared in triplicate: fish were hand-fed with control (C) diet for 10 weeks (10WF-C); four fish groups were starved for 1 week and then fed with C, high protein (HP), high lipid (HL) and combined high protein and high lipid (HPL) diets for 9 weeks, referred to as 9WF-C, 9WF-HP, 9WF-HL, 9WF-HPL, respectively; and other four fish groups were starved for 2 weeks and then fed with C, HP, HL and HPL diets for 8 weeks, referred to as 8WF-C, 8WF-HP, 8WF-HL and 8WF-HPL, respectively. Weight gain and specific growth rate of fish in 9WF-HP, 9WF-HPL, 8WF-HP and 8WF-HPL treatments were higher than those of fish in 9WF-HL and 8WF-HL treatments. Feed efficiency of fish in 8WF-HP treatment was higher than that of fish in 9WF-C, 9WF-HL and 8WF-HL treatments. Protein efficiency ratio of fish in 10WF-C, 8WF-C, 8WF-HP and 8WF-HPL treatments was higher that that of fish in 9WF-HL and 8WF-HL treatments. Juvenile olive flounder subjected to 2-week feed deprivation could achieve full compensatory growth with dietary supplementation of protein or combined high protein and high lipid.