• Korean Journal of Poultry Science
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• v.40 no.4
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• pp.361-368
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• 2013

This experiment was conducted to determine optimum levels of dietary crude protein for productivity and egg quality in laying hens during early stage. A total of seven hundred and twenty 24-wk-old Hy-Line Variety Brown layers were randomly assigned to 4 experimental diets varying with 16%, 17%, 18%, and 19% CP and fed the diets for 12 wks. There were no significant differences in egg production, daily egg mass and feed intake among experimental diets. Although no difference was found on egg weight among experimental diets, decreasing levels of dietary crude protein tended to reduce the egg weight. Haugh unit and egg shell quality were not affected by different levels of dietary crude protein. Although there was no difference on yolk color among experimental diets, increasing levels of dietary crude protein slightly reduced the yolk color. It is concluded that laying hens did not need more than 16% CP to maximize egg production.

• Journal of Animal Science and Technology
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• v.50 no.5
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• pp.695-704
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• 2008

This study was conducted to investigate effects of dietary crude protein(CP) level and supplementation of conjugated linoleic acid(CLA) on growth performances and meat quality parameters in finishing pigs. The experiment was designed using protein levels(11.3%, 16.0%) and CLA levels(0%, 2.5%) according to 2×2 factorial design. A total of forty-eight pigs [(Landrace×Yorkshire)×Duroc] with an average initial weight of 79±1kg were allotted to one of four dietary treatments. Each treatment had four replications of three pigs per replicate. Final body weight(P<0.05) and average daily gain(P<0.01) were lower in 11.3% CP treatments than in 16.0% CP treatments, while feed/gain was high(P<0.01) in 11.3% CP treatments compared with 16.0% CP treatments. Carcass weight was lighter in 11.3% CP treatments(P<0.001) and CLA 2.5% treatments(P<0.01) than in 16.0% CP and CLA 0% treatments, respectively. A significant interaction between CP and CLA on carcass weight was observed(P<0.01), where supplementation of 2.5% CLA to finishing diets decreased carcass weight in 16.0% CP treatments, while no difference was found in 11.3% CP treatments. Backfat thickness was thinner in 11.3% CP treatments and CLA 2.5% treatments than in 16.0% CP and CLA 0% treatments, respectively(P<0.05). A significant interaction between CP and CLA on backfat thickness was observed(P<0.001), where supplementation of 2.5% CLA to finishing diets decreased backfat thickness in 16.0% CP treatments, while no difference was found in 11.3% CP treatments. Marbling score and intramuscular fat contents were higher in 11.3% CP treatments than in 16.0% CP treatments(P<0.01). In conclusion, feeding of protein-deficient diets in finishing pigs could produce favorable pork with high marbling score and thinner backfat. On the other hand, supplementation of CLA was considered to decrease backfat thickness when diets with optimal level of crude protein were fed to finishing pigs.

• Korean Journal of Poultry Science
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• v.40 no.4
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• pp.351-359
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• 2013

This study was undertaken to assess dietary crude protein (CP) and amino acid (AA) concentrations for growth performance and carcass characteristics in Korean native ducks. In a $2{\times}3$ factorial arrangement, 1-d-old Korean native male ducks were allotted to 6 dietary treatments in a completely randomized design. Experimental diets contained 23 or 21% CP with 1.31/1.09, 1.21/1.00, 1.11/0.91 and 1.11/0.91, 1.02/0.83, 0.92/0.75 AA (Lysine/Total sulfur amino acid, Lysine/TSAA), respectively, from 0 to 3 wk of age. From 4 to 8 wk of age, experimental diets had 19 or 17% of diet; each contained 1.00/0.79, 0.94/0.75, 0.88/0.71 and 0.88/0.71, 0.82/0.67, 0.76/0.63 AA (Lysine/TSAA), respectively. Each dietary treatment has 6 replicates and feed and water were provided ad libitum. Body weight (BW), feed intake and uniformity were measured at 3 wk and 8 wk and carcass characteristics were evaluated at 8 wk of age. As CP increased from 21 to 23%, the BW and BW gain significantly increased (P<0.05) during 0 to 3 wk of age. From 4 to 8 wk of age, BW, feed intake, BW gain, feed conversion rations (FCR) and uniformity were not different (P>0.05) between treatments. Carcass yield and relative weights of liver, spleen, right breast and leg per 100 of BW were not different (P>0.05) between treatments. The meat color, shear force value, cooking loss and pH were not affected by dietary treatments (P<0.05). Korean native ducks require relatively low levels of dietary CP and AA for late growth and carcass yield due to low daily weight gain. This suggests the possible differences in CP and AA needs between Korean native ducks and commercial breeds from foreign breeding companies, especially late growth stage.

• Korean Journal of Poultry Science
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• v.39 no.2
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• pp.87-95
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• 2012

This experiment was conducted to investigate the effects of varying levels of metabolizable energy (ME) and crude protein (CP) on growth performance and carcass characteristics in layer-type growing male chicks. Nine hundred 1-d-old Hy-Line Brown male chicks were randomly allocated to 30 pens in a $2{\times}3$ factorial design. The experimental diets contained 2 levels of ME (2,800 kcal/kg and 2,950 kcal/kg) in combination with 3 levels of CP (17%, 18.5%, and, 20%). A significant interaction of ME and CP on feed intake was observed (p<0.05). No interaction was observed between ME and CP for 53 d BW gain or FCR, which improved linearly with dietary CP levels (p<0.05). A significant interaction or tendency was observed between ME and CP levels. The intake of ME for 1 g BW gain was linearly decreased with increasing CP levels (p<0.001). The intake of CP per bird was significantly increased in low ME (2,800 kcal/kg) treatment than that of the high ME treatment (2,950 kcal/kg) (p<0.05), and dietary CP level had more influence on CP intake for gram BW gain than level of ME. The relative weights of liver, spleen, breast meat and, leg were not influenced by the dietary treatments. Serum BUN, albumin, creatinine, and the activities of GOT and GPT were not influenced significantly by the diet treatment. In conclusion, the growth performance in layer-type male chicks was linearly increased when the level of dietary CP increased. The ME and CP did not affect the carcass characteristics and blood profiles. Therefore, the optimum levels of dietary ME and CP to improve the growth were 2,800 kcal/kg and above 18.5% in layer-type growing male chicks, respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.1
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• pp.58-65
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• 1993

The purpose of this study is to determine the evolution of carbon and nitrogen concentrations in relation to dry matter and crude protein accumulation in the leaves of forage rape(Brassica napus Subsp. oleifera, CV. Swiss) during the growth period. Field-grown plants were sampled at intervals throughout fall, winter, early and late spring. During over-wintering period(from Nov. 7 1991 to Feb. 4 1992), the carbon concentration in the leaves increased from 382 mg to 435 mg g DM$^{-1}$ , while the concentrations of nitrogen and crude protein significantly decreased. There was little accumulation of fresh and dry matter in the leaves. On early spring growth from 4 Feb. to 30 Mar. marked carbon loss 37 mg. day$^{-1}$ and slight nitrogen accumulation occurred with the increase of fresh weight in the leaves. From spring growth to bolting stage(from 31 Mar. to 16 Apr.) the greatest accumulation of fresh and dry matter was observed and carbon and crude protein concentrations increased with a linear manner. After bolting stage the concentrations of carbon, nitrogen, hydrogen and crude protein in the leaves significantly decreased until late blooming stage, and the decreasing rate was prominent in nitrogen (45.7%) and crude protein(46%). From the results above it is recommended that fertilizer will be applied before early spring growth, and that optimal utilization period is a bolting stage. For the serious modification of the internal C/N balance during the overwintering period.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.8
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• pp.1353-1358
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• 2004

This study was conducted to increase crude protein and reducing sugar contents in pollen extracts by proteases. Four commercial neutral proteases (Alcalase 2.4L, Protamex, Flavozyme and Protease A) and two alkaline proteases (Protease S and Protease P) were used to prepare acorn and Darae pollen extracts. Contents of moisture, ash, crude protein and crude fat of acorn pollen were 5.2%, 2.7%, 6.2% and 22.3%, respectively, while those of Darae pollen were 5.4%, 2.8%, 1.8% and 27.8%, respectively. Contents of crude protein and reducing sugar in pollen extracts were increased by proteases. Alcalase 2.4L was the most effective in increasing protein contents while Protease A in increasing reducing sugar contents. It is suggested the use of proteases is one of the potential methods for increasing the contents of crude protein and reducing sugar in preparation of pollen extracts.

• 사료
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• s.63
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• pp.70-76
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• 2013

사료에 있어서 가장 중요한 영양소 중에 하나는 단백질이다. 단백질은 가축의 성장, 유지, 생산근육, 효소, 호르몬, 우유, 털 등)에 필수적인 영양소이다. 가축의 단백질 요구량은 가축의 성장단계, 개체크기, 유전적인 능력 등에 따라 달라진다. 그러므로 가축에게 공급되는 단백질의 양은 정확하게 평가되어야한다. 너무 과도한 단백질 공급은 동물이 불필요한 에너지를 생산하게 만들고 너무 적은 단백질 공급은 아미노산 결핍이 일어나게 할 수 있다. 가축이 요구하는 정확한 양의 단백질을 공급하는 것이 중요하고 이를 위해서는 사료내 단백질의 양을 정확하게 분석하는 것이 선행되어야 한다. 사료에 있어 단백질 함량은 사료 내 질소의 양을 정량해서 간접적으로 환산하고 추정한 조단백질(Crude Protein)로 표현한다. 샘플내의 질소가 모두 아미노산에서 온 것이라고 가정하고, 단백질이 평균적으로 16%의 질소를 가지고 있기 때문에 (1/0.16=6.25) 정량한 질소수치에 단백질 환산 계수 6.25를 곱해서 표현한다. 그러나 사료원료마다 아미노산 조성이 다르기 때문에 사료원료마다 다른 단백질 환산 계수를 사용해야 한다는 주장도 있다. 단백질 환산 계수에 관한 리뷰논문을 보면 대두의 경우 5.71에5서부터 유제품의 경우 6.38에 이르기까지 다양하다. 그러나 논란의 여지가 있기 때문에 이렇게 매트릭스마다 다른 단백질 환산 계수를 사용할 경우 계산식 옆에 사용한 환산계수를 적어 주어야 한다. 사료 내 조단백질을 정량하는 방법은 켈달법(Kjeldahl method), 듀마스법(combustion method), 근적외선분광분석법(NIR, Near Infrared) 등이 있는데 여기서는 주로 사료분석기관과 사료업계에서 조단백질 분석에 많이 사용하고 있는 켈달법과 듀마스법을 비교해 보고자 한다.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2005.12a
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• pp.46-54
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• 2005

1. 1차 수확시기에서는 가을철 파종시기가 빠를수록 봄철의 생초수량과 건물수량이 증가되 었다. 2. 헤어리 벳치의 품종 중 Ostsaat와 Welta가 다른 품종에 비하여 생초수량과 건물수량이 다른 처리구에 비하여 유의하게 높았다. 3. 조단백질(CP) 수량은 가을철 파종시기의 차이에 따라서 변화되었는데, 특히 9월 20일 이전에 파종한 처리구에서 조단백질 수량이 증가 하였다. 4. 2차 수확시기에서 9월 20일에 파종한 처리구는 조단백질 수량이 평균1,846kg1ha로 나타나 양질의 조사료 생산측면에서 우수한 것으로 나타났다. 5. NDF와 ADF의 함량은 9웜 20일에 파종한 처리구에서 높게 나타났다. 6. TDN의 수량은 9월 20일 이전에 파종한 처리구에서 증가하였다. 7. 헤어리 벳치를 토양으로 환원시 수확시기를 늦추면 많은 양의 전질소를 얻을 수 있을 것으로 판단된다. 8. 헤어리 벳치의 품종별 가을철 적정 파종시기는 9월10일${\sim}$9월20일로 판단된다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.6
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• pp.519-525
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• 1994

This experiment was conducted to investigate the effects of sowing date and cutting time on feed value of rye in paddy field at Yesan from Oct. 1990 to June 1991. The field experiment was sown 5 times at 10 day intervals from Oct. 5. The content of crude protein, digestible protein, total digestible nutrient(TDN), minerals(P, K, Ca, Mg), and energy(ENE, NEL, NEM, NEG) were decreased due to earlier sowing, while the content of acid detergent fiber (ADF) and neutral detergent fiber(NDF) increased. On the other hand, the yields per unit area for crude and digestible protein, TDN, minerals, and energy increased due to earlier sowing, but there was no significant difference among the plots sown on Oct. 5 through Oct. 25. The highest yield of crude protein was shown at late flowering stage, digestible protein and net energy gain (NEG) at heading stage and TDN at milk stage respectively.

• Journal of Animal Science and Technology
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• v.55 no.1
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• pp.61-66
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• 2013

The purpose of this study was to determine the effects of different crude protein levels in the concentrates on carcass and meat quality of Hanwoo steers. A total of thirty 5.3-month-old castrated Hanwoo calves ($135.6{\pm}10.52$ kg) were randomly allocated into either control or treatment group. The animals were separately housed to 5 heads per group. Crude protein levels in concentrates for growing, fattening, and finishing phases were 14, 13, and 11% for control group and 16, 15, and 14% for treatment group respectively. Comparative analysis of carcass characteristics, physico-chemical characteristics, and fatty acid composition in M. longissimus dorsi of Hanwoo steers were carried out. There was no statistical difference in average cold carcass weight between control (411.9 kg) and treatment (419.9 kg) group. Also, dietary crude protein level in concentrates did not affect M. longissimus dorsi area, backfat thickness, and meat yield index. In contrast, the marbling score in treatment group was higher (p<0.05) than the control group. Also, treatment group showed significantly higher (p<0.05) values than control group for CIE L-value, Mono-unsaturated fatty acids and oleic acid composition. Therefore increasing crude protein levels of concentrates in Hanwoo steers during growing and fattening phases might be beneficial for the improvement of meat quality.