• Journal of Nutrition and Health
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• v.28 no.4
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• pp.259-267
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• 1995

A study was conducted to investigate nitrogen balance and to estimate daily nitrogen requirement in 43 Korean female college students students maintaining their usual diet and activity levels. Nitrogen intake and excretion were measured in two separate peroids about one month apart, each period lasting for 3 days. Nitrogen intake was assessed by duplicate portion analysis of diet, and N excretion in faces and urine were measured during the study period. Mean daily nitrogen intake level was 129.3mg/kg B.W and the apparent digestibility of nitrogen was 76%. Mean daily urinary nitrogen excretion was 113.5mg/kg BW. 895 of total nitrogen intake. Mean daily nitrogen balance of subjects was -14.5mg/kg BW. Mean daily requirements of nitrogen for 0 balance, calculated by regression analysis of N balance and energy-adjusted N intake. were 1) 197.mg/kg B.W with the present energy intake level of the study subjects. 2) 157mg/kg B.W when energy intake is sufficient to maintain energy balance, and 30 130mg/kg B.W. when energy intake is Korean RDA level for moderate activity. When energy intake level is sufficient to meet their requirement, daily protein requirement for 0 balance is about 1.0g/kg B.W. The results of this study indicate that nitrogen intake level of young female college students is not sufficient to meet their requirements, and they should increase protein intake together with increase in energy intake.

• Journal of Aquaculture
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• v.6 no.1
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• pp.13-27
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• 1993

In order to determine the protein requirements of the Korean rockfish Sebastes schlegeli six isocaloric diets containing crude protein level from 20\%\;to\;60\%$ were fed to two groups of fish, small and large size, with the initial average body weight of 8 g and 220 g respectively. White fish meal was used as a sole protein source. Daily weight gain, daily protein retention. daily energy retention, feed efficiency, protein retention efficiency and energy retention efficiency were significantly affected by the dietary protein content (p< 0.05). The growth parameters (that is, daily weight gain, daily protein retention and daily energy retention) increased up to $44\%$ protein level with no additional response above this point. The protein requirements were determined from daily weight gain using two different mathematical models. Second order polynomial regression analysis showed that maximum daily weight gain occurred at $56.7\%\;and\;50.6\%$ protein levels for the small size group and the large size group, respectively. However the protein requirements, determined by the broken line model, appeared to be about $40\%$ for both groups. Nutrient utilization also suggested that the protein requirements of both groups were close to $40\%$. When daily protein intake was considered, daily protein requirements per 100g of fish, estimated by the broken line model, were 0.99g and 0.35g for the small and large size groups respectively. Based on these results, a $40\%$ dietary crude protein level could be recommended for the optimum growth and efficient nutrient utilization of the Korean rockfish weighing between 8g and 300g.

• Journal of Animal Environmental Science
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• v.8 no.2
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• pp.87-98
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• 2002

This study was conducted to determine nutritional values of different sources of food residues(FR) released in autumn and to compare them with nutrient requirements on NRC standard feeding system of swine. Hospital or cafeteria FR contained more cooked rice and side dishes residues and less vegetable residues and fruit peel, resulting in higher energy and lower fiber contents, compared to apartment complex FR, which had opposite patterns to these results. Chemical composition between hospital and cafeteria FR was almost similar. Salt(NaCl) content was more than 9 folds of NRC swine requirement, but much lower than the maximum tolerant level. Essenial and non-essential amino acids profile was similar among FR sources. Hospital or cafeteria FR protein had a similar pepsin digestibility to soybean meal protein. Apartment complex FR protein, however, had a much lower pepsin digestibility. When NRC nutrient requirements are considered, FR in swine diets could satisfy requirements of protein and all the essential amino acids, 75${\sim}$111% of digestible or metabolizable energy, and most of the major and minor minerals. All the FR contained extremely low levels of toxic heavy metals, indicating that they are completely safe from these toxic substances. It was concluded that hospital or cafeteria FR could be a nutritionally excellent and balanced feed source for swine.

• Journal of Animal Science and Technology
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• v.48 no.4
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• pp.533-540
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• 2006

This experiment was conducted to determine crude protein requirements for maintenance (CPm) of growing Hanwoo steers. Eighteen Hanwoo steers (173.7kg) were allocated randomly to diets with three levels of crude protein in the concentrate by replacing ground corn with corn gluten meal: 0% (LCP), 7.2% (MCP) and 14.2% (HCP), respectively. Hanwoo steers in each treatment were fed diets containing rice straw (20%) and concentrates (80%). CP intake was 5.5, 7.8 and 10.7g/BW0.75 for LCP, MCP and HCP, respectively. Protein balance was －0.05, 2.36 and 4.07g/BW0.75 for LCP, MCP and HCP, respectively. Intercept of the regression equation between CP intake and retained CP indicated that CPm was 5.56g/BW0.75. The estimate of CPm adopted by Korean Feeding Standard (2002) was almost 20% higher than that adopted by Japanese Feeding Standard for Beef Cattle (2000); this would need to be verified with more feeding trial data set including protein requirements for growth.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.2
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• pp.357-363
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• 1992

The experiment was carried out to estimate the energy and protein requirements of Khaki Campbell $\times$ Thai Native growing ducks. The growing stage was divided into 2: the first was a starting stage from 0 to 4 weeks of age and the second was a growing stage from 4 to 18 weeks of age. In the starting stage, the birds were given diets containing 2.70, 2.75, 2.80, 2.85 and 2.90 Mcal ME/kg and ME/protein ratio of 150/l for the energy requirement trial, and diets containing 17.0%, 18.5%, 20.0% and 21.5% protein and 2.8 Mcal ME/kg for the protein requirement trial. It was found that there were no significant differences in body weight gain of feed efficiency among the energy or protein levels. In the growing stage, no significant differences in body weight gain or feed efficiency were found among the energy levels from 2.70 to 2.90 Mcal ME, or protein levels from 15.5% to 20.0%. The age at first lay was 105-117 days and this is earlier than that observed in purebred Khaki Campbell ducks. The feed cost for raising ducks was lower in the low energy and low protein diets. In conclusion, Khaki Campbell $\times$ Thai native ducks can be raised with a diet low in ME as 2.7 Mcal/kg during the whole growing period. As for the protein. 7.0% in the starting stage and 15.5% in the growing stage is practical.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.3
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• pp.388-394
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• 1999

Two experiments were conducted to subdivide isoleucine (exp. 1) and valine (exp. 2) requirements for maintenance from the requirements for growth of broilers aged 1 to 3 weeks. Purified diets were used, containing five graded levels of isoleucine and valine. Based on weight gain response, the isoleucine requirement for growth was 7.50 mg/g weight gain and the daily isoleucine need for maintenance (mg) was 0.044 per unit metabolic body size ($(Wg^{0.75})$). Based on the N gain response, the isoleucine requirement for growth was 0.317 mg/mg N gain and the daily isoleucine need for maintenance (mg) was 0.040 per unit metabolic body size $(Wg^{0.75})$. Based on weight gain and N gain response, the total isoleucine requirement was calculated 244 mg/day or 0.59% of the diet, 274 mg/day or 0.66% of the diet, respectively. From the relationship of weight gain and N gain, 5.07% of the retained protein was comprised of isoleucine; the reported isoleucine content of chick muscle was 4.42%. The valine requirement for growth was 9.84 mg/g weight gain and 0.36 mg/mg N gain whereas the maintenance requirement was 0.046 or 0.052 mg per unit of metabolic body size (Wgo.11. According to the model developed to estimate valine requirement, the total requirement was 319 mg/day or 0.77% of the diet, 315 mg/day or 0.76% of the diet, respectively. Previous reported valine requirements for growing chicks of 7~24 days old were in close agreement with these estimates. As a percentage of retained protein, valine was calculated to be 5.81% ; the reported valine concentration of crude protein of chicks' body including feathers was 6.72%.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.5
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• pp.605-612
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• 2000

Four young swamp buffalo cows of similar age ranging in weight between 280 to 380 kg and trained to do physical work were used in a study to determine energy and protein requirements for draught using a $4{\times}4$ Latin square designed experiment. The experiment consisted of field trials employing 4 levels of work load, e.g. no work as control, and loads amounting 450 to 500 Newton (N) pulled continuously for 1, 2 and 3 h daily for 14 consecutive days. Cows were fed king grass (Penisetum purpuroides) ad libitum and were subjected to materials balance trials. Body composition was estimated in vivo by the body density method and daily energy expenditure (EE) was calculated from ME minus retained energy (RE). The results show that EE while not working ($EE_{resting}$) was $0.42kgW^{0.75}MJ/d$ and maintenance ME ($ME_m$) was $0.37kgW^{0.75}MJ/d$. ME requirement increased to 1.65 times maintenance for the work of 3 hours. The energy expended for doing exercise ($E_{exercise}$) was 9.56, 20.0 and 25.86 MJ/cow for treatments 1, 2 and 3 II, respectively. Fat retention was absent in all groups of working cows, but protein retention was only negative for cows undertaking 3 h work. The relationship between $E_{exercise}$ (MJ), work load (F, kN), work duration (t, h) and body mass (W, kg) was found to be: $E_{exercise}=(0.003F^{1.43}t^{0.93})/W^{0.09}MJ$. The maintenance requirement for digestible protein was $2.51kgW^{0.75}g/d$, whereas digestible protein for growth ($DP_{growth}$) and for work ($DP_{work}$) followed the equations: $DP_{growth}=[(258+1.25W^{0.75}){\Delta}Wkg/d]g$ and $DP_{work}=[12.59e^{0.95t}]g$, respectively The coefficients a, b and c for the calculation of $E_{exercise}$ components according to the Lawrence equation were found to be 2.56 J/kgW.m, 5.2 J/kg load carried.m and 0.29, respectively, thus efficiencies to convert ME into work were 0, 16.09, 27.3 and 32.44% for control, 1, 2 and 3 h/d work, respectively. ME and DP requirements for a 250 to 400 kg working buffalo cow allowing to growth up to 0.5 kg/d are presented.

• Journal of Nutrition and Health
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• v.55 no.1
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• pp.10-20
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• 2022

This article evaluated levels of Estimated Average Requirements (EARs), Reference Nutrient Intakes (RNIs), and Acceptable Macronutrient Distribution Ranges (AMDRs) of protein using the recently revised Dietary Reference Intakes (DRIs) for Koreans (2020). Dietary protein requirements are based on amounts sufficient to satisfy physiological demands to accomplish nitrogen equilibrium. The same principle was applied to estimate EARs and RNIs, for adults in DRIs conducted in 2015 and 2020 in Koreans. EAR was estimated to be 0.73 g/kg body weight/day, according to data (0.66 g/kg body weight/day) obtained using the nitrogen balance method and adjusted by efficiency of protein use (90%). RNI was calculated as EAR increased by an amount equal to twice the standard deviation of an age group so as to cover 97.5% of the group and was found to be 0.91 g/kg body weight/day. For weaned infants, children, and adolescents, growth requirement was added to estimate EAR. In particular, growth requirement was adjusted by efficiency of protein use in the revised EAR, which led to higher EARs for weaned infants, children, and adolescents of both genders as compared with 2015 DRIs. The AMDR for protein was set at 7%-20% of energy intake, which was the same as 2015 DRIs. Current, average protein intake by the Korean population is almost twice times the EAR, which suggests it might be better to increase the minimal margin for AMDR. However, it was not adjusted in this revision due to lack of evidence.

• Journal of Biosystems Engineering
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• v.27 no.5
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• pp.433-450
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• 2002

The daily food intake for dairy cows has to be effectively controlled to breed a sound group of cows as well as to enhance the productivity of the cows. But, feed stuffs are fed in the common bulk for a group of cows in most cases despite that the individual food intake has to be varied. To obtain the feed for each cow, both the nutrient requirements and the nutrient composition of fred have to be provided in advance, which are based on the status of cows such as weigh marginal weight amount of milk, fat concentration in milk, growth and milking stages, and rough feed ratio, etc. Then, the mixed ration fur diet would be computed by the nutrient requirements constraints. However, when TMR (Total Mixed Ration) is conventionally supplied for a group of cows, it is almost impossible to get an optimal feed mixed ration meeting the nutrient requirements of each individual cow since the constraints are usually conflicting and over-constrained although they are linear. Hence, addressed in this paper is a simulated annealing (SA) technique to find the food intake for dairy cows, considering the characteristics of individual or grouped cows. Appropriate parameters fur the successful working of SA are determined through preliminary experiments. The parameters include initial temperature, epoch length. cooling scheduling, and stopping criteria. In addition, a neighborhood solution generation method for the effective improvement of solutions is presented. Experimental results show that the final solution for the mixture of feed fits the rough feed ratio and some other nutrient requirements such as rough fiber, acid detergent fiber, and neutral detergent fiber, with 100 percent, while fulfilling net energy for lactating, metabolic energy, total digestible nutrients, crude protein, and undegraded intake protein within average five percent.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.783-789
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• 2020

This study was conducted to evaluate growth performance of weaned pigs using diets based on ideal protein of the Korea swine feeding standard (KFS) and US the nutrient requirements of swine (NRC). A total of 96 weaned (initial body weight of 6.12 ± 1.21 kg) pigs were randomly allocated into 2 dietary groups with 12 pens per diet (4 pigs·pen-1) in a completely randomized design. The dietary treatments were corn and soybean meal-based diets formulated by the KFS and NRC nutrient requirements estimates for weaned pigs. Experimental diets were fed for 6 weeks in 2 phases feeding program based on age: 1) Phase 1 = week 1 to 3 (21 days); 2) Phase 2 = week 4 to 6 (21 days). During Phase 1 and 2, there were no differences (p > 0.05) for the initial and final body weights between the KFS and NRC groups. Additionally, the average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio (G : F) during overall experimental period were not different between the groups. In conclusion, weaned pigs fed the diet based on the KFS had a similar body weight and growth performance to those fed the diet based on the NRC. This suggests that the Korea swine feeding standard may be used for the diet formula of weaned pigs in Korea swine production compared with the US nutrient requirements of swine.