• Asian-Australasian Journal of Animal Sciences
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• v.23 no.4
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• pp.501-507
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• 2010

Three hundred chicks were randomly assigned among four treatments to evaluate the effect of an organic selenium supplement at various levels of dietary protein. Two levels of supplemental selenium (0 and 0.3 mg/kg) from zinc-L-selenomethionine were tested at two levels of dietary protein (normal and reduced) in a completely randomized design with $2{\times}2$ factorial layout. The experiment lasted up to 49 d of age during which all birds were exposed to $31{\pm}1^{\circ}C$. The effects of selenium or its interaction with CP on growth performance and carcass characteristics were not significant. However, feeding the reduced-CP diet decreased weight gain in the starting period and increased liver and abdominal fat weights relative to body weight. Ferric reducing ability of plasma (FRAP) was not significantly affected by dietary CP and Se or their interaction though FRAP values were numerically higher in the Se-supplemented group. Dietary CP content did not affect the activity of plasma glutathione peroxidase (GSHPx), though Se significantly elevated plasma GSHPx activity. The interaction of CP and Se was not significant for FRAP and plasma GSHPx activity.

• Journal of Nutrition and Health
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• v.22 no.1
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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.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.2
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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.

• Journal of Nutrition and Health
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• v.29 no.6
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• pp.578-589
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• 1996

This study was performed to invstigate the effect of dietary protein level and source on cadmium intoxicification in rats. Forty-eight male rats of Sprague-Dawley strain weighing 171$\pm$3g were blocked into 8 groups of 6 animals according to body weigth, and were raised for 30days. Eight experimental diets different with cadmium(0ppm, 400ppm)and protein(15%, 40%) levels and protein source[casien, I.S.P.(isolated soy protein)] were given to animals for 30days. Food intake, weight gain, food efficiency ratio, liver weight, kidney weight and femur weight were lower in cadmium added group, and higher in high protein groups(40% protein) than medium protein groups(15% protein). But, dietary protein source had no influence on them. Cadmium concerntration of liver was higher in rats fed casein than I.S.P. groups, and cadmium concentration in intestine was higher in high protein groups. In femur both high protein and I.S.P.diets increased cadmium concentrations. MT concdentrations in liver, kidney and intestine were higher in cadmium added group, and kidney intestine MT concentration were higher in high protein group. Absorption and retention rates of cadmium were lower in rat fed I.S.P. than animal fed casein among medium protein groups and cadmium concentration in blood and liver of I.S.P groups were lower than casein groups. But absorption and retention rates of cadmium were similar in high casein and I.S.P. groups. Renal damage by cadmium administration was not seen in all groups. Absorption rates of zinc and copper competing with cadmium in absorption process were lower in high protein groups than medium protein groups and lower in rats fed I.S.P. than casein. In conclusion, weight gain, F.E.R, and MT concentraion of high protein groups were higher than those of medium protein groups and absorption and retention rates of cadmium were lower in high protein groups. From these results, it was shown that cadmium toxicity was alleviated by high dietary protein. Meanwhile, the effect of dietary source on the cadmium toxicity was different with protein level. In medium protein groups absorption and retention rates of cadmium were much lower in rats fed I.S.P. than casein. In high protein groups, cadmium toxicity was not influenced by protein source and absorption and retention rates of cadmium were not different between casein and I.S.P. groups.

• Journal of Life Science
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• v.7 no.4
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• pp.329-335
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• 1997

This study was conducted to investigate the effect of dietary fiber(DF) levels on the meat quality in colored broiler. Colored broiler were fed on containing corn-soy basal diet(DF 5%) and high level(DF 6,7 and 8%) of dietary fiber diets for 7 weeks. Dietary fiber level of diet was make up by adding some alffalfa meal. Colored broiler meats were stored at 3$\circ$ for 24hr after skaughter, and used to analyze physico-chemical properties. Proximate component, pH, shear force value, myofibril fragmentation index, water holding capacity, cooking loss, protein extractability, fatty acid composition, Hunter's L, a value and palatability of cooked meat were not significantly affected by dietary fiber levels, whereas the Hunter's value of meat was significantly affected bty dietary fiber levels for the final period of feeding. Crude protein content, myofibril fragmentation index, water holding capacity, protein extractability and Hunter's b value of breast meat's were higher than thigh meat's, but crude fat content, pH, shear force value, cooking loss, palmitoleic acid, linolenic acid, and Hunter's a value were lower, regardless of dietary fiber level.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.936-942
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• 1997

The present study was carried out to investigate the effects of dietary protein and magnesium levels on calcium and magnesium metabolism in male Sprague-Dawley rats. Forty-eight male rats(average weight, 210g) divided into six diet groups; protein 8% and Mg-free diet, protein 8% and Mg 400mg/kg diet, protein 8% and Mg 900mg/kg diet, protein 20% and Mg-free diet, protein 20% nd Mg 400mg/kg diet, and protein 20% and Mg 800mg/kg diet group. After the rats were fed with experimental diets concentration were examined. Kidney weight was significantly higher in protein 8% and Mg-free group compared with other groups. Serum calcium concentration of protein8% group tended to decrease with the increase of the level of magnesium. Serum magnesium concentration in protein 8% and 20% group was lower in Mg-free group than that in other groups(p<0.05) and it also increased as the dietary magnesium level was increased. Urinary calcium and magnesium concentration in Mg-free group were significantly lower than those of other groups.

• Korean Journal of Poultry Science
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• v.14 no.1
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• pp.25-31
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• 1987

This experiment was conducted to study the most economical and effective dietary protein level and feeding regimes in the performance of broilers. Four kinds of dietary protein level (25, 23, 20 and 18%) were prepared for this experiment. This experiment was carried on for 7 weeks and the results were shown as follows; 1. Increasing the dietary protein level resulted in a significant increase in the body weight gains (P〈0.05). 2. With a higher level of the dietary protein, the feed intake tended to be increased and the feed efficiency had same trends. 3. Increasing the dietary protein level resulted in a significant increase in the protein requirement per kg body weight gains (P〈0.05). 4. Viabilities were not affected by the different dietary protein levels. 5. The highest income had attained in the highest level of protein supplement, and the middle level of protein supplement was not higher than the lowest one. Conclusively, the highest level of protein supplement was considered to be adequate for the broiler's productiveity and income.

• Journal of Nutrition and Health
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• v.27 no.1
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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.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.1
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• pp.123-128
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• 1992

In Experiment 1, when fasted chicks were fed diets containing various sources of protein for 3 days, the activities of lipogenic enzymes (acetyl-CoA carboxylase, fatty acid synthetase, citrate cleavage enzyme and malic enzyme) in the liver of growing chicks were significantly lower in the soybean protein or gluten diet than in the casein or fish protein diet. Triglycride contents of the liver and plasma of chicks fed the casein or fish protein diet were significantly lower than that of those fed soybean protein or gluten diet. In Experiment 2, the effects of dietary amino acid mixture simulating casein or protein on the activities of hepatic lipogenic enzymes were examined. The activities of acetyl-CoA carboxylase and fatty acid synthetase in the liver of chicks fed the casein diet were significantly higher than that of those fed the soybean protein diet or two diets of amino acid mixtures. Furthermore, there were no significant differences between the two diets of amino acid mixture based on casein or soybean protein. However, the activities of malic enzyme and citrate cleavage enzyme tended to be lower in the soybean-type amino acid diet than in the casein-type amino acid diet. Thus, some effects can be ascribed to the protein itself and some to the amino acid composition of the protein sources.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.8
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• pp.1151-1158
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• 2008

This study was designed to examine the effects of different dietary protein levels on growth performance, nutrient utilization, amino acid (AA) digestibility and serum biochemical parameters of preruminant dairy calves. Fifteen healthy new-born calves were randomly allotted to three experimental groups and fed with different milk replacer that contained 18% (LP), 22% (MP) or 26% (HP) of protein. The results showed that final BW, net gain and ADG were significantly higher in the MP group than in LP and HP groups (p<0.05). In addition, the apparent digestibility of CP in the MP group was significantly higher than in the other two groups (p<0.05). The values of N intake and fecal N excretion were significantly increased following the increase of dietary protein content (p<0.05). However, in all three groups of animals, dietary protein content had no significant effect on urinary N concentration (p>0.05). BUN concentration, on the other hand, decreased as calves grew but increased following the increase of dietary CP content. Furthermore, no significant differences in digestibility of amino acids were observed among these three groups of animals (p>0.05). We concluded that calves fed with milk replacer containing 22% of protein had better growth performance and nutrient utilization as compared to animals treated with milk replacer containing either 18% or 26% of protein.