• Asian-Australasian Journal of Animal Sciences
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• 제14권1호
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• pp.61-69
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• 2001

A total of 120 pigs were used to investigate the effects of yucca extracts on the growth performance, nutrient digestibility and excretion of growing pigs fed different levels of dietary protein. Pigs were allotted into $2{\times}3$ factorial design by the supplementation with yucca extract (YE, 0 and 120 mg/kg) and 3 levels of dietary protein (16, 18, 20%). During the whole experimental period (18 to 52 kg body weight), there were no significant differences in ADG, ADFI or F/G by YE addition or different protein levels among treatments (p>0.05). Overall, although addition of YE to the diet and elevation of protein level showed better ADG, there were no significant differences in growth performance among treatments. Pigs fed diets with YE showed significantly (p<0.05) higher dry matter (DM), crude ash (CA) and crude protein (CP) digestibility than did the others during the growing period. Concerning the levels of dietary protein, only the CP digestibility was significantly higher in pigs fed high protein diet. Pig fed the low protein diet without YE showed a significantly low CP digestibility (p<0.05). No significant differences were found in crude fat (CF), calcium (Ca) and phosphorus (P) digestibilities regardless of YE supplementation or dietary protein levels. Pigs fed YE supplemented diets showed significantly (p<0.05) higher amino acid digestibility. Also, high CP level diets showed a higher amino acid digestibility than low CP diets (p<0.05). DM and N excretion did not show any significant differences among treatments, there was a slightly lower excretion with increase in dietary protein level. Supplementation with YE significantly decreased the DM and N excretion. Interaction (YE$\times$protein) was found in P excretion. Pigs fed a medium protein diet without YE showed the lowest P excretion during the growing period. The NH3-N content in the feces tended to be increased by the increased dietary protein levels and with YE supplementation. During the whole experimental period, the cost for YE supplementation was similar to value of the improvements of performance obtained. The cost of feeding high level protein was significantly higher than that of medium level protein by 10% and low level protein by 9% (p<0.05). It could be concluded that the effects of dietary protein level and yucca extract on growth performance, nutrient digestibility and excretion might play a role to some extent in growing pigs from the aspect of pollution control.

• Asian-Australasian Journal of Animal Sciences
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• 제6권2호
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• pp.235-242
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• 1993

In order to investigate the effects of dietary cellulose and protein levels on chick performance, four semi-purified diets were formulated so as to contain cellulose at levels of 5% (LC) and 20% (HC) in combination with 10% (LP) and 20% (HP) protein, and fed ad libitum to 1-week-old White Leghorn male chicks for 3 weeks. There were no significant differences in feed intake, body weight gain and feed efficiency between the LC-HP and HC-HP groups. All parameters were lower in the LP groups; the HC-LP group consumed very small amount of feed and lost body weight during the experiment. The retention rates of DM, ash, nitrogen and energy were higher in the HP than the LP groups. The triglyceride concentration of carcass was lower in the HC-LP group and that of liver was higher in the LC-LP group. The carcass total cholesterol level was higher in the HC-HP group. The relative weight of most digestive organs was higher in the HP group irrespective of the cellulose level. In conclusion, the chick performance was primarily influenced by dietary protein level, and when the chicks were fed inadequate levels of protein, the low cellulose level gave a better performance than the high cellulose level.

• Journal of Nutrition and Health
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• 제29권10호
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• pp.1059-1071
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• 1996

This study was performed to investigate the effect of dietary protein level on renal senescence. Male rats of 337.8$\pm$5.7g body weight were underlateral nephrectomy or shamoperation. The rats were divided into high protein(40% casein), normal protein(15% casein) and low protein(8% casein)diets and fed experimental diets ad libitum for 24 weeks. The results are summarized as follows. There was a hypertophy of the remnant kidney of uninephrectomized rats of 40% or 15% protein group, coming up to the comparable weights of both kidneys of sham-operated rats. However, the hypertrophic effect was not seen in uninephrectomized rats of 8% protein group. Serum albumin was lower in uninephrectomized rats. With increasing dietary protein level blood urea nitrogen was increased, whereas, urinary urea nitrogen excretion was decreased. Urinary solute excretion was higher in uninephrectomized group than in sham-operated group. However, effect of dietary protein level on urinary solute excretion varied dpending on th solutes tested. GFR and urinary protein excretion, throughout experiment, increased with feeding period and with dietary protein level. Proteinuria was most severe in uninephrectomized rats fed 40% casein diet. Maximum urine concentration ability measured after dehydration was not different among the experimental groups. Light microscopic examination showed focal segmental glomerulosclerosis and mild increas of glomerular mesangial matrix in uninephrectomized rats fed 40% and 15% protein diet, however, which was not observed in uninephrectomized rats fed 8% protein diet and in sham-operated rats fed 40% diet. Immunofluorescence studies revealed segmental deposits of albumin in the mesangium and capillary loops in high protein and uninephrectomized groups. Minimal granular deposition of IgG was noted in the mesangium of all experimental groups. In conclusion, high protein intake accelerated deterioration of renal function and it was correlated with morphological change. Low protein intake was effective in preventing these changes.

• Journal of Nutrition and Health
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• 제23권6호
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• pp.401-407
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• 1990

본 연구에서는 식이단백질 수준이 성장기 흰쥐의 신장 발달과 기능에 미치는 영향을 조사하기 위해 평균체중이 97.5$\pm$1.9g인 숫컷 흰쥐를 5%, 15% 그리고 50% casein 식이로 6주간 사육하였다. 체중증가량은 단백질 수준이 높을수록 높았으며 특히 단백질수준이 신장무게에 미친영향이 간, 비장, 흉선 등이 다른 장기에 비해 컸다. 신장내 총 DNA와 RNA 함량에서는 유의적인 차이가 없었다. 총 protein과 단위 g당 protein 함량은 식이내 단백질수준이 높을 수록 증가했다. 사구체여과율(GFR)은 식이단백질 수준이 높을수록 높았으나 신혈류(RBF)는 각 군 사이에 유의적인 차이를 보이지 않았다. 뇨질소배설량은 단백질 수준에 비례하여 유의적인 차이를 보였고 노칼슘배설량은 5%군이 낮은 경향을 보였다. 본 연구 결과로 성장기의 흰쥐에서 고단백식이는 신장의 무게증가를 촉진하며 사구체여과율을 증가시킴을 알 수 있다.

• Journal of Nutrition and Health
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• 제26권7호
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• pp.851-857
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• 1993

Atherosclerotic vascular disease is a major cause of the increased morbidity and mortality assciated with diabetes mellitus. The prominent role of nutrition in hypercholesteolemia and atherosclerosis is generally accepted. Diet is a key element in the management of diabetes (type I-IDDM), yet the appropriate diet for patient with diabetes mellitus is not well known. Dietary protein has been shown to have a significant effect on plasma cholesterol levels in both experimental animals and humans. The present experiment was designed to determine the effect of the dietary protein level(20% vs 60%) on plasma glucose concentration, lipids profile, insulin and glucagon levels from non-diabetic and streptozotocin-induced diabetic rats. Results showed that a high protein diet decreased triglyceride concentration in diabetic rats. Also diabetic rats fed a high protein diet were hypocholesterolemic than rats fed a control diet. There were no effects by level of protein on fasting blood glucose concentration and insulin/glucagon ratio. Results from the present study suggest that a high protein diet may be beneficial to control pasma lipids in chemically-induced diabetic rats.

• Asian-Australasian Journal of Animal Sciences
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• 제27권1호
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• pp.55-61
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• 2014

Forty-eight Pelibuey${\times}$Katahdin male intact lambs ($23.87{\pm}2.84$ kg) were used in an 84-d feeding trial, with six pens per treatment in a $2{\times}2$ factorial design arrangement. The aim of the study was to evaluate the interaction of two dietary energy levels (3.05 and 2.83 Mcal/kg ME) and two dietary protein levels (17.5% and 14.5%) on growth performance, dietary energetics and carcass traits. The dietary treatments used were: i) High protein-high energy (HP-HE); ii) High protein-low energy (HP-LE); iii) Low protein-high energy (LP-HE), and iv) Low protein-low energy (LP-LE). With a high-energy level, dry matter intake (DMI) values were 6.1% lower in the low-protein diets, while with low-energy, the DMI values did not differ between the dietary protein levels. Energy levels did not influence the final weight and average daily gain (ADG), but resulted in lower DMI values and higher gain efficiencies. No effects of protein level were detected on growth performance. The observed dietary net energy (NE) ratio and observed DMI were closer than expected in all treatments and were not affected by the different treatments. There was an interaction (p<0.03) between energy and protein level for kidney-pelvic and heart fat (KPH), KPH was higher in lambs fed high energy and high protein diet but not in high energy and low protein diet. The KPH was increased (20.2%, p = 0.01) in high-energy diets, while fat thickness was increased (21.7%, p = 0.02) in high-protein diets. Therefore, it is concluded that dietary energy levels play a more important role in feed efficiency than protein levels in finishing lambs with a high-energy diet (>2.80 Mcal/kg ME). Providing a level of protein above 14.5% does not improves growth-performance, dietary energetics or carcass dressing percentage.

• 한국식품영양과학회지
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• 제23권1호
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• pp.13-22
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• 1994

This study was designed to investigate the effects of dietary protein and caffeine consumption levels on Ca, P, Na and K metabolism. One hundred twenty rats were divided into twelve groups according to age, protein level and caffeine consumption such as group(120-130g young rat, 250-300g adult rat) , dietary protein group (20% normal protein , 85 low protein) , caffeine consumption group(0, 3.5mg, 7.0mg). Low protein diet containing high caffeine levels caffeine levels increased calcium, phosphorus, sodium and potassium contents of urine and fecal in rats. Young rat has higher level of calcium, phosphorus , sodium and potassium than adult rat. In the serum, calcium contents were not affected by age, dietary protein levels and caffeine consumption . However, phosphorus, sodium and potassium contents of serum in adult rat were higher than young rat. In the liver, potassium decreased with decreasing dietary protein levels. In the kidney, calcium , phosphorus and potassium contents were not different by age group, dietary protein levels and caffeine consumption , but sodium content was significantly reduced in the adult rat.

• Asian-Australasian Journal of Animal Sciences
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• 제11권4호
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• pp.391-397
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• 1998

The present study was conducted to examine the effects of dietary protein (20, 22, 24%) with a constant protein-to-energy ratio on clenbuterol-induced performance in broilers. The protein-to-energy ratio was based on adequate level (22% protein, 3,100 kcal of energy). Female broiler chickens were used for a $3{\times}2$ factorial arrangement and fed diets with or without 1 ppm clenbuterol from 14- to 32-days of age. Feed efficiency improved with increasing dietary protein level, regardless of clenbuterol treatment. The dietary clenbuterol increased weights of breast and leg muscles (gastrocnemius and peroneus longus), and clenbuterol markedly reduced protein content of leg muscles in chickens fed the 20% protein diet, but did not in chickens fed the 22 and 24% protein diets. Feeding the 24% protein diet with clenbuterol improved the protien accretion (peroneus longus) by 8.4%. Clenbuterol decreased DNA content and increased the protein/DNA ratio in breast muscle regardless of dietary protein intake. Clenbuterol had no effect on RNA content in both breast and leg muscles. The present results demonstrated that various protein levels which retain the same protein-to-energy ratio in the diet markedly alter the protein accretion induced by ${\beta}$-agonist in broilers.

• 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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• 제22권1호
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• pp.9-22
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• 1989

The effect of different levels of Zn (0, 30, 300ppm) and protein(7, 20, 40%) in the diet upon lipid metabolism was investigated in Sprague-Dawley male rats weighting 180.54$\pm$29.08g(n=450 fed one of nine diets in a 3$\times$3 factorial design for 5 weeks. The reults obtained were summarized as following. 1) Total lipid contents in serum and liver were tended to be lower in LZn group than CZn and Hzn groups. Those of LP group were higher than CP and HP groups. 2) HDL-cholesterol and total cholesterol contents in serum were significantly affected by dietary Zinc level and were increased as dietary Zinc level increase. 3) Total cholesterol in liver and muscle were tended to be decrease as dietary Zinc level increase. Those in LP group were higher than CP and HP groups. 4) Zinc contents in plasma, liver, muscle and testis were tended to be lower in LZn group than CZn and HZn groups. 5) Protein contents in plasma and liver lower in LZn group than CZn and HZn groups when dietary protein level was 7% and 20%. Those in LP group were lower than those in CP and HP groups. 6) Cu contents in plasma, liver, muscle and testis were tended to be decreased as dietary Zinc level increase.