• Korean Journal of Poultry Science
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• v.11 no.1
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• pp.1-12
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• 1984

Since a 13% dietary protein level is generally accepted as a standard in evaluating net protein utilization values of protein sources in chicks, limiting amino acids a 13% protein basal diet containing 15% isolated soy-protein as the only source of dietary protein, were identified. Of such amino acids as methionine, lysine, threonine and tryptophan added to the basal diet singly or as a combination, methionine appeared as the only limiting amino acid for optimum growth of the chicks. When the requirement of total sulfur-containing acids (TSAA) was estimated as the point at which the dose-response curve intersected a line representing the plateau for maximum performance, the TSAA requirements for maximum growth and feed intake were 4.73% and 3.73% of dietary protein, respectively. The values, expressed in terms of TSAA intake, required for maximum weight gain, feed intake and gain/feed ratio were 167.1, 136.8 and 159.1 mg/bird/day, respectively.

• Korean Journal of Poultry Science
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• v.14 no.1
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• pp.39-53
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• 1987

A total of 1,440 White Leghorn pullets hatched in summer and winter, aged 20 to 72 weeks were fed 9 rations differing in dietary protein (13, 15 and 17%) and energy (2,500, 2,700 and 2,900 kcal/kg) levels for a period of 52 weeks in order to evaluate the optimum dietary energy and protein levels for laying hens. As metabolizable energy level increased from 2,500 to 2,900 kcal/kg of feed egg production, daily feed and protein intake and egg shell quality decreased, but reverse was true for the daily energy intake, energy requirement and feed cost per kg egg, body weight gain, nutrients utilizability and abdominal fat accumulation, Egg weight, viability and egg yolk Pigmentation were not affected by the dietary energy level. On the other hand, as dietary protein level increased from 13 to 17%, egg production, egg weight, daily protein intake, protein requirement per kg egg and body weight gain icreased, but daily feed and energy intake, feed and energy requirement per kg egg, egg yolk pigmentation and dry matter utilizability decreased, and no significant difference in the feed cost per kg egg, viability and egg shell quality was observed among dietary protein levels. However: the hens fed 15% and 17% Protein diets did not show significant differences in egg production, egg weight and body weight gain. For the entire laying period of 52 weeks, metabolizable energy level of 2,500 kcal/kg of feed and 15% dietary protein level were considered to be adequate to support the optimum productivity.

• Journal of Korean Home Economics Education Association
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• v.24 no.2
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• pp.51-62
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• 2012

This research examined the method and amount changes of recommended protein intakes(RPI) for male and female adult, and pregnant lactating women from 1962's Recommended Dietary Allowances for Korean(KRDA) to 2010's Dietary Reference Intakes for Koreans(KDRIs) revised. As male and female adult's RPI calculation, factorial method was applied until 1989 KRDA, after that nitrogen balance study was applied. Basal factor in factorial method was standard protein(egg or milk protein) requirement or obligatory nitrogen(protein) loss. On the other hand, basal factor in nitrogen balance study was minimum dietary protein requirement to maintain nitrogen equilibrium balance(nitrogen intake = nitrogen excretion). Adjusting factors of RPI were stress and/or protein requirement difference among people. The RPI of male adults were 50~80 g/day, that of female adults were 45~70 g/day. The additional RPI of pregnant women were 10~30 g/day, were calculate based upon the extra protein needs caused by unborn child development. The pregnant women's additional RPI of 2010's KDRIs revised in the periods of first, second, and third trimester were 0, 15, 30 g/day, respectively. The additional RPI of lactation women were 20~30 g/day, were calculated based upon the extra protein needs caused by maternal milk secretion.

• Korean Journal of Microbiology
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• v.33 no.1
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• pp.7-14
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• 1997

This study was to elucidate the relation between the periodical requirement of growth factors(Yang et al., 1993) and the synthesis of RNA and protein during the germination of Streptomycn coefic%r A3(2) in mineral liquid medium(ISP-4) without addition of growth factors. As results, The germination time was about 10 hr, and meanwhile, periodical nutritional requirement was verified to be repeated with interval of 2 hr. Spore size was enlarged with time but its number was rather decreased. Spore could be deviJed into viable, dormant, and dead state. In such a germination process it was found that RNA and protein were being synthesized periodically when spores were stained with AO and INT methods and observed under the fluorescence microscope. Those syntheses were coincided with the period of nutritional requirement. Hence, it was discllssed that spore population in early germination would need amino acids related to protein synthesis.

• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.633-638
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• 2007

This study was conducted to determine the protein requirement level in growing Jindo dog through nitrogen balance experiment. Twelve female dogs aged 18～20 weeks old were allotted one of 3 dietary treatments containing 21, 23 and 25% of crude protein. Average daily gain of dogs fed experimental diets containing 21, 23 and 25% of crude protein were 65.42, 79.58 and 99.17g/d, respectively, and there was a significant difference between 21 and 25% of crude protein treatments(p<0.05). Retained nitrogen were calculated 0.74, 0.96 and 1.31g/kgBW.75/d for dogs fed diets containing 21, 23 and 25% of crude protein, respectively, and were significantly higher(p<0.05) in dogs fed 25% of crude protein diet then those of other dogs. A quadratic regression equation was calculated between nitrogen intake(x) and nitrogen retention(y); y=-2.519x2+12.79x-14.79, and it was found a significantly(p<0.05) higher regression coefficient of 0.782. From the above equation, it was estimated maintenance requirement of crude protein for growing Jindo dog is 11.25g/kg BW.75/d.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.10
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• pp.1452-1460
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• 2014

The objective of this work was to evaluate the nutritional parameters of young bulls supplemented with different ratios of protein: carbohydrate on tropical pastures from 4 until 18 months old. Fifty-five non-castrated beef calves ($138.3{\pm}3.4kg$, 90 to 150 d of age) were used. The calves (young bulls) were subjected to a 430-d experimental period encompassing 4 seasons. The treatments were as follows: control, only mineral mixture; HPHC, high protein and high carbohydrate supplement; HPLC, high protein and low carbohydrate supplement; LPHC, low protein and high carbohydrate supplement; and LPLC, low protein and low carbohydrate supplement. The amount of supplement was adjusted every 28 d. Dry matter (DM) intake was higher in the dry-to-rainy transition and rainy seasons for all nutritional plans. Non-supplemented animals had lower intakes of DM and total digestible nutrients (TDN) than supplemented young bulls in all seasons. Although differences in DM intake were not observed between supplemented animals, the supplements with high carbohydrate (HPHC and LPHC) had lower forage intake during suckling (rainy-to-dry transition season) and in the rainy season. However, the HPHC treatment animals had higher intake and digestibility of neutral detergent fiber. It can be concluded that supplementation with high protein levels (supplying 50% of the crude protein requirement) provide the best nutritional parameters for grazing young bulls in most seasons, increasing intake and digestibility of diet, and these effects are more intense when associated with high carbohydrate levels level (supplying 30% TDN requirement).

• Fisheries and Aquatic Sciences
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• v.24 no.3
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• pp.129-137
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• 2021

Dietary protein requirements of abalone (Haliotis discus) depending on abalone size were determined and compared. One thousand and fifty small abalone (initial weight of 2.7 g) and five hundred forty large one (initial weight of 16.0 g) were distributed into 15 and 18 containers in Trial 1 and 2, respectively. Five and six experimental diets containing crude protein level from 20% to 40% and 20% to 45% with 5% increment of protein level for the small and large abalone were prepared and referred to as the CP20, CP25, CP30, CP35, CP40, and CP45 diets, respectively. The experimental diets were fed to abalone for 16 weeks in Trials 1 and 2. Specific growth rate (SGR) of the small abalone fed the CP20 diet was lower compared to that of abalone fed all other diets in Trial 1. Growth performance (weight gain and SGR) of the large abalone fed the CP30, CP35, and CP40 diets were greater than that of abalone fed the CP20, CP25, and CP45 diets in Trial 2. Dietary protein requirements were estimated to be 33.0% and 33.5% for the small and large abalone based on the 2^nd order polynomial analysis, respectively. Dietary protein requirements for the small abalone grown from 2.7 g to 7.4 g and the large one grown from 16 g to 21 g were estimated to be 33.0% and 33.5%, respectively. Size differences in abalone did not affect dietary protein requirement under this experimental conditions.

• Korean Journal of Poultry Science
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• v.15 no.3
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• pp.229-246
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• 1988

These studies were conducted to investigate the effects of dietary protein and metabolizable energy(ME) levels on layer performance during summer period. Total 480 ISA Brown egg-type layers ageing 49 weeks housed 2 birds per cage with 4 replictes of 20 birds were employed in this study. Mean environmental temperature over experimental period ranged from 22.3$^{\circ}$to 29.5$^{\circ}C$. The treatments consisted of dietary ME levels of 2500, 2700, 2900kcal/kg of diet containing 15% and 17% protein, respectively, to provide $3{\times}2$factorial design. As metabolizable energy level increased form 2500 to 2900 kcal/kg of diet, daily feed and protein intake, egg production. egg weight, egg mass decreased, but the reverse was true for the daily energy intake, energy requirement and feed costs per kg egg. Feed conversion(kg feed/kg egg) and viability were not affected by the dietary energy levels. However, there were no significant difference in egg production, protein requirement per kg egg, and egg weight between those hens fed 2500 kcal ME/kg diets and those fed 2700 kcal ME/kg diets, and no difference was found in egg weight between those fed 2700 kcal ME/kg and those fed 2900 kcal ME/kg, either. In addition, no specific trend was observed in protein requirement per egg by the different level of metabolizable energy in diets. On the other hand, as dietary protein level increased from 15 to 17%, daily protein in-take, egg production, egg weight, egg mass, and protein requirement and feed costs per kg egg increased, but feed and energy requirement per kg egg decreased, and no significant difference in the daily feed and energy intake and viability were observed among dietary protein levels. It was concluded that metabolizable energy level of 2500 kcal/kg of diet and 17% dietary protein level were considered to be adequate to support the optimum productivity of layers during summer period.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.4
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• pp.704-713
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• 1997

This study was conducted to describe qualitatively the protein metabolism of pigs during growth depending on the feed protein quality and to describe quantitatively amino acids requirements, using a simulation model. The used model has a non-linear structure. In the used model, the protein utilization system of a pig, which is in the non-steady-state, is described with 15 flux equations and 11 differential equations and is composed with two compartments. Protein deposition(g/day) of pigs on the 30th, 60th, 90th, and 120th day of feeding duration with three-quality protein, beginning with body weight 20kg, were calculated according to the empirical model, PAF(the product of amino acid functions) of Menke, and was used as object function for the simulation. The mean of relative difference between the simulated protein deposition and PAF calculated values, lied in a range of 8.8%. The simulated protein deposition showed different behavior according to feed protein quality. In the high-quality protein, it showed paraboloidal form with extending growth simulation up to 150eh day. So the maximum of protein deposition was acquired on the 105th day of simulate growth time and then it decreased fast. In the low-quality protein, this form of protein deposition in the course of simulated growth did not appear until 150th day. The simulated protein mass also showed a difference in accordance with feed protein quality. The difference was small on the 30th day of simulated growth, but with duration of the simulated growth it was larger. On the 150th day the simulated protein deposition of high quality protein was 1.5 times higher as compared to the low-quality protein. The simulated protein synthesis and break-down rates(g/day) in the whole body showed a parallel behavior in the course of growth, according to feed protein quality. It was found that the improvement of feed protein quality increased protein deposition in the whole body through a increase of both protein synthesis and breakdown during growth. Also protein deposition efficiency, which was calculated from simulated protein deposition and protein synthesis, showed a difference in dependence on the protein qualify of feed protein. The protein deposition efficiency was higher in pigs fed with high quality protein, especially at the simulation time 30th day. But this phenomena disappeared with growth, so on the 150th day of growth, the protein deposition of the high feed protein quality was lowest among the three different quality of feed protein. The simulated total requirement of the 10 essential amino acids for the growth of pigs was 28.1(g/100g protein), similar to NRC. The requirement of lysine was 4.2(g/100g protein).

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.1
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• pp.75-79
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• 1992

Fourteen Sahiwal ${\times}$ Friesian crossbred heifers were used in a 10-wk feeding trial to determine maintenance energy requirements and efficiency of gain. The heifers were individually fed with a diet consisting of 30% dry grass and 70% concentrates at either 110, 140 or 180% of the anticipated maintenance requirement ($494kJ\;ME/kg^{0.75}/day$). Liveweight of individual heifers was measured weekly to calculate diet requirements and average daily gain (ADG). Diet digestibility was determined for all heifers to determine ME intake. Retained energy (RE) of individual heifers was determined from changes in total body fat and protein using a TOH isotope dilution procedure and, assuming calorific values of 39.3 and 23.6 kJ/g for fat and protein respectively. The estimated ME for maintenance was 433 and $470kJ/kg^{0.75}/day$ by liveweight (ADG) equilibrium and energy (RE) equilibrium analysis respectively. ME requirement for one g of liveight gain was 28 kJ.