• Korean Journal of Poultry Science
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• v.42 no.1
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• pp.87-100
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• 2015

It is well known that dietary protein affects the growth performance and carcass composition of poultry. Over the last several decades, numerous studies have been carried out to investigate to optimize the level of dietary protein since the protein is an important and expensive constituent in poultry feed. It is generally accepted that dietary protein should represent a balance of amino acids supporting the requirements for growth and maintenance of birds. A protein with balanced essential amino acids that matches a bird's requirement and sufficient non-essential amino acid nitrogen to enable the synthesis of all of the non-essential amino acids, is referred to as an 'ideal protein'. Feeding of excess protein or amino acids may result in an amount of nitrogen emission. Most common method to reduce nitrogen emission is using diet formulation which has lower dietary crude protein level and higher concentration of amino acid supplements. However, there are conflicting reports whether low protein diets supplemented with synthetic amino acids can obtain the growth performance equal to high protein diets. Excessive nitrogen excretion caused by amino acid imbalance also may influence the environment of poultry house due to ammonia production from uric acid. These environmental conditions may increase the incidence of skin problem or respiratory diseases of chickens. Various strategies based on comprehensive understanding should be tested to optimize nitrogen utilization and reduce nitrogen emission while maintaining the performance in poultry production.

• Journal of Nutrition and Health
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• v.29 no.10
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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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• v.25 no.3
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• pp.256-263
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• 1992

As various metabolic alterations develope in uremic patients. their diets need to be restricted, Furthermore medical complications with accompanying anorexia result in further complications and decrease in body strength. To assess the nutritional status of hemodialyzed patients we performed evaluation for dietary intake and protein catabolic rate(PCR) For 24 clinically stable male patients undergoing maintenance hemodialysis dietary intake was estimated by 3-day food record method and PCR was calculated with blood urea nitrogen at pre and post hemodialysis. The results were as follows : 1) Average daily energy and protein intake were 26.7$\pm$5.1kcal/kg of body weight. 0.95$\pm$0.19 g/kg of body weight respectively. 2) Protein catabolic rate calculated from interdialysis blood urea nitrogen levels was 1.00$\pm$0.20g/kg of body weight. Protein catabolic rate was correlated with the amount of Protein intake(r=0.44 p<0.05) 3) Relative body weight(RBW) of the subjects was smaller than that of healthy man without hemodialysis. Calorie and protein intake and protein catabolic rate were significantly different (p<0.05) between patients with lower RBW(<90% of ideal body weight) and those with normal RBW(90~110% of ideal body weight) and those with normal RBW(90~110% of iedal body weight) 4) The duration of hemodialysis did not have a significant effect on the nutritional status of the subjects.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.1
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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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• v.6 no.3
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• pp.339-342
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• 1993

This influence of dietary medium chain triglyceride on liver protein synthesis in chicks was investigated using a large dose injection of $L-[4-^3H]$ phenylalanine. Dietary medium chain triglyceride increased liver weight and liver fat content of chicks compared to the long chain triglyceride group. Fractional synthesis rate of liver protein was increased by dietary medium chain triglyceride, which was accounted for not by elevating protein synthesized per unit RNA but by enhancing RNA: protein ratio.

• Journal of the East Asian Society of Dietary Life
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• v.7 no.1
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• pp.1-11
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• 1997

The purpose of this study was to describe the protein nutritional status of female collegians between nonvegetarian diet groups(14) and vegetarian diet groups(19). Daily intake, protein were calculated from food direct measurement. Urea/creatinine, muscle mass, fatique conditions and hematological parameter were calculated. Blood samples were analyzed for total protein, albumin ammonia, urea, uric acid, creatinine, BUN contents. The results obtained are summarized as following : 1) On total dietary intake, especially Fe, vitamin C, niacin intake, vegetarian groups were higher than non vegetarian groups. 2) On composition of EAA(essential amino acids), vegetarians were highter than non vegetarian of leucine contents, but were lower lysine and threonine contents. 3) On urea / creatinine excretion, vegetarians were higher than non begetarians. Muscle mass were non signicant, fatique condition, vegetarians were normal state. 4) Non vegetarians were increased serum albumin total protein, uric acid, ammonia but vegetarians were decreased BUN, ammonia after experimental diet intake. 5) In process of time after meal, non vegetarians were increased serum albumin total protein, BUN, but vegetarians were decreased ammonia.

• Nutrition Research and Practice
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• v.9 no.3
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• pp.313-318
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• 2015

BACKGROUND/OBJECTIVES: Dietary pattern and its association with cardio-cerebrovascular disease have not been studied in Baoji city by now. This study was aimed to identify the dietary patterns among Chinese adults in Baoji, and explore the association between these dietary patterns and cardio-cerebrovascular disease. SUBJECTS/METHODS: A total of 4,968 participants were included in this study at 12 counties. With multistage stratified random sampling and semi quantitative food frequency questionnaire, the prevalence of cardio-cerebrovascular disease and dietary intake were investigated in 2013. We used factor analysis to establish dietary patterns. RESULTS: A total of 4,968 participants over 15 years old were included in this study. Five dietary patterns were identified in Baoji: protein, balanced, beans, prudent, and traditional patterns. The protein dietary pattern mainly included animal and plant proteins and was negatively associated with hypertension as well as stroke. The balanced pattern included carbohydrates, protein, and fat and was negatively associated with hypertension as well as stroke. The beans pattern was mainly beans and beans products and was negatively associated with hypertension. The prudent pattern only included staple foods and pickled vegetables and was positively associated with hypertension as well as coronary heart disease. The traditional pattern was representative of local Baoji traditional recipes and was positively associated with hypertension. CONCLUSIONS: The protein, balanced, and beans dietary patterns showed many protective effects on cardio-cerebrovascular disease. Based on these results, Baoji city residents should be encouraged to choose protein, balanced, and beans dietary patterns and abandon prudent and traditional patterns to prevent incidence of hypertension, coronary heart disease, and stroke.

• 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.9 no.3
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• pp.331-335
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• 1996

A study was conducted to determine the carcass composition of broilers when fed with three varying levels of dietary energy (3,000, 3,200 and 3,400 kcal/kg ME) at 20% crude protein and 0.79% Total Sulphur Amino Acid. The results showed that there was a significant (p < 0.05) increase in the ME intake of the chickens when the ME of the diet increased. Other factors like the protein intake, dressing percentage, weight gain and feed intake were not significantly affected. On the carcass, the increasing dietary ME levels resulted in a significant (p < 0.05) increase in the abdominal fat percentage and carcass fat percentage and a significant (p < 0.05) decrease in the carcass protein percentage. Similarly, the dietary ME produced a significant (p < 0.05) increase in the amount of and fat percentages of breast meat, thigh meat, and drumstick meat with a significant reduction in the protein percentage. There seemed to be an inverse relationship between the percentages of protein and fat. An increase in fat percentages always resulted in similar reduction in the protein content of the meat. These results also showed major differences between the white and red meat of the chicken.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2006.11a
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• pp.17-27
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• 2006

The effects of dietary betaine on performance, blood compositions, hepatic amino acid concentrations and hormonal secretions were examined in laying hens. Egg production was significantly higher in birds fed the 16.5 % protein diet compared to those fed 14.5 % protein diet(p<0.05), whereas dietary supplementation of betaine did not show any significant effect. The high level of protein and betaine supplementation significantly improved egg weight, egg mass and feed conversion(p<0.05), while eggshell breaking strength, eggshell thickness and Haugh unit were not influenced by betaine and dietary protein levels. Supplemental betaine did not affect serum total protein, albumin and BUN concentration. However, uric acid concentration significantly increased in 600 ppm betaine-fed groups(p<0.05). Concentrations of most hepatic amino acid were influenced by increased protein feeding and dietary betaine supplementation. Hormone studies recorded significantly higher serum and hepatocyte IGF-I concentration in 600 and 1,200 ppm betaine treatments(p<0.05) compared to those of control group. IGF-I mRNA gene expression of hepatocytes revealed statistically correlated increase in 600 and 1,200 ppm betaine-fed groups compared to the controls(p<0.05). Serum IGFBP-3 concentration was significantly elevated in 600 ppm betaine treatments. However, the secretion of IGFBP-1 in hepatocyte of laying hens fed with 600 and 1,200 ppm of betaine showed a significant decrease compared to the control group(p<0.05). Results of these study show that dietary betaine supplementation affects protein and hormone metabolism in laying hens.