• Korean Journal of Poultry Science
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• v.23 no.2
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• pp.85-98
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• 1996

Results of experiments on the nutrient requirements and feeding system of broiler breeder hens were reviewed, and daily requirements of energy and protein were calculated using the prediction equations reported by Scott(1977) and NRC(1981). The experimental reports on daily ME needs of broiler breeder hens were ranged from 400 to 450 kcal, however, the ME needs of caged hens were 92~93% to those of floor-housed hens due to the difference of ME need for activity. The ME needs of broiler breeders decreased with increasing environmental temperature corresponding to a drop of 25 kcal per day for each 5˚C rise. About 80~90% of the daily ME needs were used for body rnaintenance and activity of hens. Experimental results on daily protein needs of broiler breeder hens were ranged from 18 to 22 g, however, calculated protein needs decreased as the BW gain and eggmass output decreased after peak production, and about 60~65% of the daily protein needs were used for egg production. In the current practice, broiler breeder hens are restricted in feed, and consume their daily allowance in the first 2 to 6 h after dawn. The results suggest that eggshell quality can be significantly improved in hens fed during the afternoon when shell calcification is initiated, with no adverse effect on laying rate and fertility of eggs.

• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.3
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• pp.177-181
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• 2020

Data on the crude protein requirements of elk doe are nonexistent and the data are essential for their management in Korea. Therefore, this study was conducted to evaluate the crude protein requirement for maintenance of elk doe. Three female elk deer were used in 3 × 3 Latin square design with three diets containing three levels of crude protein (CP) that contained low crude protein (approximately 12%), medium crude protein (15%), and high crude protein (18%). Each three elk doe trials included a 14-day preliminary period and a 5-day collection period. Crude protein intake was 4.83, 6.26, and 9.00 g/d for 12%, 15%, and 18% of CP level, respectively. Crude protein balances were 1.04, 1.41, and 4.14 for 12%, 15%, and 18% of CP level, respectively. The maintenance requirement for CP from the regression equation between CP intake and CP balance were 3.70 g/BW^0.75.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.5
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• pp.675-681
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• 2002

Among Italian buffalo farmers, it is widely held that administering diets with high energy and protein concentrations is an effective way to increase milk production. In order to assess the validity of this opinion, we verified milk yield and physico-chemical characteristics from buffaloes that, from the $5^{th}$ month of lactation, were fed two total mixed rations (TMRs) which, given the same intake, should have led to satisfaction of protein requirements though with a slight energy deficit (diet A) or excessive amounts of energy and protein (diet B). Estimate of the energy and protein value of the diets and that of the corresponding requirements was carried out both by using two software programs derived from the Cornell Net Carbohydrate and Protein System (1992), and with the method set up by INRA researchers (1988). The results obtained show that the two diets administered did not result in significant changes to the quantity of milk produced. However, with Diet B the protein concentration in the milk was significantly (p<0.01) higher, although this was partly offset by the higher concentration (p<0.05) of non-protein nitrogen (NNP). The Group B buffaloes also showed significantly higher blood urea levels (p<0.01), with concentrations exceeding those considered physiological for lactating buffaloes. Finally, while administering Diet A the Body Condition Score (BCS) was close to 6.5 (Wagner et al., 1988), whereas in buffaloes which used Diet B it sometimes increased by over 0.5 points. As regards which of the two methods compared is more suitable for expressing dietary energy and protein value and corresponding requirements, we feel that due to the high variability in the Italian Mediterranean buffalo's milk production aptitude, it would be premature to express a judgement on methods which rest on a common scientific base and do not differ substantially.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.1
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• pp.107-111
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• 1996

Studies on the effects of protein levels on the total sulphur amino acid (TSAA) requirements of chickens were conducted on the starter broilers by feeding four levels of crude protein(16, 18, 20 and 23%) at three levels of TSAA (0.83, 0.93 and 1.03%) and on the grower broilers by feeding three levels of crude protein (16, 18 and 20%) at three levels of TSAA(0.72, 0.79 and 0.86%). The metabolisable energy of the diets was maintained constant at 3,200 kcal/kg and the experiments were carried out for two growing periods: starter (0-3 wk) and grower (3-6 wk). The results showed that there were significant differences in body weight gain, feed intake and feed:gain ratio under different protein levels of the starters. Crude protein, ME and TSAA intake were significantly affected by increasing the CP levels. The TSAA requirement of the starter broilers is recommended at 0.93% and it is not influenced by different protein levels used in the experiment. For the grower period, body weight gain and feed:gain ratio improved significantly at higher protein diets. Birds fed higher protein diet consumed greater quantities of protein. Responses to TSAA supplementation for body weight gain, feed intake and feed:gain ratio were not significant. The present results showed that the TSAA level of 0.79 to 0.86% was required for grower diets and that the protein levels of the diet did not influence the TSAA requirement.

• Journal of Nutrition and Health
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• v.28 no.5
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• pp.406-414
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• 1995

Nitrogen(N) concentration of preterm(PT) and term (T) milk in various fractions, such as total, protein, nonprotein, whey protein and casein were determined at 2-5 days, 1, 2, 4 and 6 weeks of postpartum. The purpose of this study was to investigate the nitrogen concentration of human milk from mothers delivering at preterm and term, and the propriety of preterm milk for premature infants. The concentration of total N, nonprotein N, protein N, whey protein N and casein N in preterm milk was decreased significantly with time postpartum. Total N was 374mg/이 at colostrum, 232mg/dl at mature milk. Whey protein N was decreased from 42mg/dl at 2-5 days to 32mg/dl at 4-6 weeks. Protein N was 332mg/dl at colostrum, 202mg/dl at mature milk. The proportion of whey protein N and casein N were 39:61 at colostrum, 28:72 at mature milk. No difference were found between T and PT milk for total nitrogen excepted 2 weeks. In this report we show that nitrogen concentration except casetpt casein N is smaller in milk from mothers giving birth prematurely than in milk from mothers giving birth at term, over the first two weeks of lactationl But protein N was higher in preterm milk than term milk, whey protein nitrogen was lower. By comparing predicted nitrogen intakes to estimated requirements of preterm infants fed 150 to 200ml/kg/day of their own mother's milk, we predict that the quantities of protein provided would be adequate to meet the requirements of the prematured infants during the early weeks of life.

• Journal of Animal Science and Technology
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• v.62 no.5
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• pp.628-637
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• 2020

In poultry diets, a requirement of crude protein is one of the most important factors in poultry productivity. Besides, the Pekin duck requirement of crude protein is still not clear. This experiment was conducted to determine the crude protein requirement of Pekin duck on diet formulation by investigation of growth performance, carcass trait, and analysis of blood parameter for a hatch to 21-day (d) of age. A total of 432 male White Pekin ducks were randomly allocated to six levels of crude protein (i.e., 15%, 17%, 19%, 21%, 23%, and 25%) to give six replicate pens per treatment with 12 ducklings per each pen. Body weight and feed intake were measured weekly by calculating feed conversion ratio and protein intake. Two ducklings each pen was euthanized via cervical dislocation for analysis of carcass trait and plasma blood on 21-d of age. Data were applied on both prediction linear-plateau and quadratic-plateau models by estimation of the crude protein requirements. Data were applied on both prediction linear-plateau and quadratic-plateau models by estimation of the crude protein requirements. The level of crude protein requirements of Pekin ducks for 21 days after the hatch was estimated to be 20.63% and 23.25% diet for maximum daily gain, and minimum feed conversion ratio, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.2
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• pp.365-368
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• 1992

The experiment was carried out to estimate the energy and protein requirements of Khaki Campbell $\times$ Thai Native laying ducks. To estimate the energy requirement, 5 experimental diets were formulated at levels of 2.70, 2.75, 2.80, 2.85 and 2.90 Mcal ME/kg. These diets were equal in ME/CP ratio (170/l). A total of 150 18-week old laying ducks were assigned to 5 energy level treatments, each comprising 3 replicates of 10 birds each, and they were fed the diets for 18 weeks. To estimate the protein requirement, 90 18-week old laying ducks were divided into 9 groups of 10 birds each, and they were assigned to 3 protein level treatments, each comprising 3 replicates. The levels of protein in the diets were 13.5%, 15.0% and 16.5%, and all diets were isocaloric (2.8 Mcal ME/kg). As a result, the 16.5% protein diet gave significantly better egg production than the 13.5% and 15.0% protein diets, however, no significant difference in egg production was found among the energy levels. Feed cost to produce 1k eggs was lower in the 2.70 Mcal and 16.5%protein diets than in the higher ME and lower protein diets.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.1
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• pp.69-73
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• 1992

Two experiments were conducted with one-day-old straight run Muscovy ducklings to determine their protein and energy requirements. In the 1st experiment, isoenergetic diets (2800 kcal ME/kg) with three dietary proteins, 18, 20 and 22% in the starter period (1-28 days) and 16, 18 and 20% in the grower and finisher period (29-84 days) were used to determine the optimum protein requirement. While, in the 2nd experiment, isonitrogenous diets (20%, C.P.) with three dietary energy, 2700, 2800 and 2900 kcal ME/kg in the starter period (1-28 days) and (18% C.P.) with 2800, 2900 and 3000 kcal ME/kg in the grower-finisher period (29-84 days) were used to determine the optimum energy requirement. It was observed that 20% C.P. in the starter period and 18% C.P. in the grower and finisher period was adequate for optimum performance, while, 2900 kal ME/kg was sufficient to meet the optimum energy requirement in both the starter, grower-finisher period as regards body weight, feed efficiency, protein efficiency and caloric efficiency are concerned.

• 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.

• Animal Bioscience
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• v.36 no.4
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• pp.601-608
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• 2023

Objective: This study was conducted to investigate the effects of energy and protein levels in the diet of Hanwoo heifers on growth response and animal behavior. Methods: Forty heifers were randomly allocated into three experimental groups according to the target daily weight gain in 8 pens (T-0.2, 2 replications; T-0.4 and -0.6, 3 replications) based on similar body weight (BW) and age in months. The target average daily gain (ADG) was set at 0.2 (T-0.2), 0.4 (T-0.4), and 0.6 kg/d (T-0.6), and feed was based on National Institute of Animal Science (NIAS, 2017). In order to minimize hunger stress of T-0.2 and -0.4, the feeding ratio of rice straw was set to 55%, 50%, and 45% for T-0.2, -0.4 and T-0.6, respectively, so that the dry matter (DM) intake for all treatment groups was uniform but the energy and protein levels in the diet were adjusted differently. A total of 6 items (lying, standing, eating, rumination, walking and drinking) of animal behavior were analyzed. Results: During the whole period of the experiment, the ADG of the T-0.2, -0.4 and -0.6 treatments were 0.48, 0.56, and 0.65 kg/d (p<0.05), respectively, showing higher gain than the predicted value, especially for the low target ADG group. Based on these results, regression equations for the total digestible nutrient (TDN) and crude protein (CP) requirements were derived. No behavioral differences were found according to the energy and protein levels in the diet because the DM intake was kept constant by adjusting the roughage and concentration ratio. However, eating time was longer (p<0.05) at T-0.2 than T-0.6 during the whole day. Conclusion: Through this study, it was possible to derive regression equations for predicting TDN and CP requirements according to the target ADG and BW.