• 생물환경조절학회지
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• 제12권1호
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• pp.45-53
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• 2003

본 연구의 목적은 차광스크린 및 인공광을 이용하여 온실에 적절한 일일적산 광합성유효광량자속을 공급하는 기술을 개발하는 것이다. 차광율이 55%와 85%인 두 가지 종류의 차광스크린을 이용하여 목표광량을 얻는데 필요한 차광시간대를 분석한 결과, 조절하고자 하는 목표광량의 크기에 따라 적절한 차광율을 가진 차광재를 선택할 필요가 있는 것으로 판단되었다. 기상조건에 따라 광량변화가 많은 7월과 8월에 대하여 55%의 차광재를 이용하여 광조절 실험을 실시한 결과 무차광시의 실측값과 계산값의 차이가 최대 5 mol$.$ $m^{-2}$ $.$$d^{-1}$ 정도로 나타났다. 이러한 차이는 기상조건에 따라 일일적산 광량이 큰 차이가 있음을 감안하면 대체로 만족할 만한 결과로 판단된다. 광분포 시뮬레이션을 이용하여 적절한 광배치를 찾을 수 있었기 때문에 실제 인공광을 배치하는데 소요되는 시간을 많이 단축할 수 있었지만, 정확하게 목표한 광강도를 고르게 분포하도록 할 수 있는 광배치를 찾기가 쉽지 않았으며, 이에 대한 보다 더 많은 분석이 요구되었다. 목표한 일일적산 광합성유효광량자속을 얻는데 필요한 보광강도별 보광시간을 기상조건 및 월별로 계산하여 분석한 결과 보광강도는 필요보광량의 크기에 따라 적절한 값을 선택하여야 할 것으로 판단되었다. 55%차광재 및 300$\mu$mol$.$ $m^{-2}$ $.$ $s^{-1}$의 보광강도를 이용하여 5월말에서 6월초까지 광량 제어실험을 실시한 결과 최대 3mol$.$ $m^{-2}$ $.$$d^{-l}$ 정도의 오차를 보여주었다. 이러한 차이는 동일한 달에 같은 기상조건에서도 일일적산 광량의 차이가 있고 하루 중 기상상태도 많은 변화가 있기 때문인 것으로 판단된다. 그러나 기상조건에 따른 일별 최대차이가 30 mol$.$ $m^{-2}$ $.$$d^{-l}$ 정도임을 감안하면 조절효과는 만족할 만한 결과로 판단된다. 본 연구의 결과는 비록 상추재배를 위한 광량조절기술이지만 다른 작물에 대해서도 본 연구에서 제시한 자료 및 조절방법을 동일하게 적용할 수 있을 것으로 기대된다.

• Asian-Australasian Journal of Animal Sciences
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• 제12권3호
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• pp.400-410
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• 1999

Five experiments were conducted using finishing pigs (PIC L326 sires $\times$ C15 dams) to examine the effects of expander operating conditions on nutrient digestibility in finishing pigs. The effects of different expanding conditions (0, 11.7, 24.4, $32.5kg/cm^2$) for corn-SBM based diets (Exp. 1), wheat meddlings diet (Exp. 2), sorghum-SBM based diets (Exp. 3) and wheat-SBM based diet (Exp. 4). Exp. 5 was conducted as a $2{\times}4$ factorial arrangement and factors examined were 2 soy products (raw soybean and SBM) and 4 expanding conditions (0, 14.1, 28.1, $42.2kg/cm^2$). In experiment 1, total production rates (p>0.10) were similar among treatments. The amount of fines decreased (cubic effect, p<0.001) as cone pressure was increased from 0 to $11.7kg/cm^2$, with smaller differences as cone pressure was further increased to $35.2kg/cm^2$. Nutrient digestibilities increased (p<0.02) as the feed was subjected to higher cone pressures. Digestibilities of DM, N, and GE were maximized at $24.4kg/cm^2$ cone pressure. The DE of the diet expanded at 24.4 and $35.2kg/cm^2$ increased by 172 and 109 kcal/kg, respectively, compared to the diet processed at $0kg/cm^2$ cone pressure. In experiment 2, total production and screened pellets production rates were similar among the processing treatments (p>0.21). The amount of fines decreased (quadratic effect, p<0.03) by 9 kg/h as cone pressure was increased from 0 to $11.7kg/cm^2$. Digestibilities of DM (p<0.02), N (p<0.001), and GE (p<0.002) were increased as cone pressure was increased from 0 to $35.2kg/cm^2$. DM, N, and GE digestibility in the pigs fed the midds-based diet increased by 8, 13, and 10%, respectively, at the highest processing cone pressure compared to the diets without any cone pressure. In experiment 3, the conditioned mash moistures for the treatments were numerically similar around 15% moisture. As the expander cone pressure was increased from 0 to $11.7kg/cm^2$, energy consumption for the pellet mill decreased (quadratic effect, p<0.004) from 14.1 to 12.0 kWh/t. Dry matter and gross energy digestibility increased (cubic effects, p<0.006) as cone pressure was increased from 0 to $35.2kg/cm^2$ with the largest improvement occurring as cone pressure was increased from 0 to $11.7kg/cm^2$. Nitrogen digestibility increased (cubic effect, p<0.001) from 78.3 to 81.0% as the feed was subjected to the higher cone pressures, with N digestibility being maximized at $24.4kg/cm^2$ cone pressure. The DE of the diet increased (cubic effect, p<0.001) by 225 kcal/kg as cone pressure was increased from 0 to $11.7kg/cm^2$. In experiment 4, pellet moisture decreased and moisture loss increased as cone pressure was increased from 0 to $35.2kg/cm^2$. Also, starch gelatinization of the wheat-based diets increased from 16.8 to 49.1% as the diets were processed at 0 and $35.2kg/cm^2$ cone pressure. Nutrient digestibilities were not affected (p>0.18) by any increase in cone pressure. In experiment 5, pellet moisture decreased as cone pressure was increased 0 to $35.2kg/cm^2$. The amount of moisture loss for the diets expanded at $42.2kg/cm^2$ was 3.0 and 3.8% for the SBM and raw soybean (RB) diets, respectively. Starch gelatinization for the SBM diets were 19% greater than the RB diets. The RB diets had lower DM, N and GE digestibilities as compared to the SBM diets. The DE of the RB diets were lower (p<0.02) than the SBM diets. DM (p<0.06), N (p<0.02), and GE (p<0.001) digestibilities of the dietary treatments increased as cone pressure was increased 0 to $42.2kg/cm^2$.

• 환경영향평가
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• 제30권3호
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• pp.141-154
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• 2021

본 연구에서는 전산유체역학(CFD) 모델을 이용한 수치 모의에서 춘천시 약사지구 도시 재정비 사업에 의한 약사천 복원과 아파트 단지 건설이 주변 지역의 오염물질 농도에 미치는 영향을 분석하였다. 사업에 의한 영향을 비교하기 위해 도시재정비 사업 전과 후인 2011년과 2017년의 지형 자료를 이용하여 바람장과 오염물질 농도장을 모의하였다. 수치 실험에서 아파트 단지 건설의 영향과 하천 복원의 효과를 구분하여 분석하도록 시나리오를 구성하였다. 대상 지역의 평균적인 배경 바람장을 반영하기 위해 춘천 종관기상관측소(ASOS)의 풍향 및 풍속 자료를 유입 경계 조건으로 사용하고, 모의 결과를 유입 풍향의 8방위별 빈도에 따라 가중평균하였다. 시나리오 간 건물·지형 변화에 따른 풍속과 NO_X 농도 분포의 차이를 비교하였다. 그 결과 주변 도로에서 배출된 NO_X 농도는 아파트 단지 건설에 의해 증가하였으며, 아파트 단지 건설과 하천 복원을 함께 고려한 결과에서는 증가 폭이 감소하였다. 이를 지점별로 나누어볼 때, 복원한 하천 주변으로는 NO_X 농도가 감소하는 한편, 건설한 아파트 단지 주변으로는 농도가 크게 증가하였다. 아파트 단지 주변의 NO_X 농도 증가는 풍향을 기준으로 아파트 단지의 후면에 위치한 곳에서 더욱 뚜렷하였으며, 그 영향은 건물 높이까지 나타났다. 이러한 결과를 통해 사업 대상 지역의 주풍향에 대한 아파트 단지 건설과 하천 복원의 상대적인 배치가 주변 대기질을 결정하는 주요 요소임을 확인하였다.

• 생명과학회지
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• 제18권11호
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• pp.1584-1591
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• 2008

클로렐라의 생리활성작용 중 인슐린작용 활성 및 항당뇨효능이 보고된 바 있으나 클로렐라 열수 추출물(Chlorella hot water extract, CE)에 의한 혈당치 조절에 관한 연구는 보고된 바 없다. 따라서 본 실험에서는 실험적인 당뇨유발물질 streptozotocin (STZ)을 성장기 SD계 수컷 흰쥐에 단회 복강 주사하여 당뇨를 유발시킨 CE 무첨가 STZ-Control군, CE 3% 첨가 STZ+CE3군 및 CE 6% 첨가 STZ+CE6군, 그리고 정상군(Normal군)으로 실험 설계하여 4주간 식이와 함께 물을 자유 급여하였다. 공복 및 비공복시 혈당치는 정상군보다 당뇨 대조군에서 현저히 증가하여 당뇨 유발이 확인되었고, 이러한 혈당치 증가는 클로렐라 열수 추출물 분말 3% 첨가 STZ+CE3군 및 6% 첨가 STZ+CE6군에서 각각 감소하였다. 혈중 인슐린 농도는 당뇨 대조군에서 낮게 나타났으나 클로렐라 열수 추출물 분말 첨가식이 투여군들에서 인슐린 농도 감소현상이 상쇄되었다. 또한 정상군보다 STZ- 당뇨 대조군에서 Fructosamine 및 뇨당이 증가하였으나, 클로렐라 추출물 투여 STZ+CE3군 및 STZ+CE6군에서 감소하는 경향을 나타내었고, 특히 이러한 효과는 클로렐라 열수 추출물 첨가농도 의존적이었다. 클로렐라 추출물 투여군에서 혈당치 감소의 기작을 검토하기 위하여 인슐린 합성과 분비에 관여하는 췌장의 췌도 베타세포의 면역반응에 의한 조직검사에서 정상군의 정상적인 둥근 모양의 형태를 잘 유지하고 있었으나, STZ-당뇨 대조군에서는 베타세포가 심하게 파괴되어 극소수 존재함으로서 면역 반응성이 매우 미약하였다. 그러나 클로렐라 열수 추출물 투여군에서 농도 의존적으로 베타세포가 많아지면서 정상군과 비슷한 췌도 세포의 형태를 유지하고 있었다. 클로렐라 열수 추출물은 STZ 에 의해 파괴된 베타세포를 회복시키는 효능이 강한 것으로 보여 진다. 이러한 결과는 클로렐라 열수 추출물에 의해 인슐린을 생산해 내는 췌도 베타세포가 회복됨에 따라 인슐린 증강 작용으로 혈당치 강하 효과가 실험 동물을 통하여 확인되었다.

• 한국가금학회지
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• 제39권3호
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• pp.167-175
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• 2012

본 실험은 대사 에너지와 조단백질 수준이 토종오리의 생산성 및 도체 특성에 미치는 영향을 연구하기 위해 수행되었다. 육성 전기는 토종오리 828수를 9개 처리에 공시하여 사용하였고, 육성 후기는 육성 전기를 거친 토종오리 중 720수를 9개 처리에 공시하여 사용하였다. 육성 전기의 실험 사료는 ME 3,000, 2,900 및 2,800 kcal/kg, CP 23, 22 및 21%이었으며, 육성 후기에는 ME 3,100, 3,000 및 2,900 kcal/kg, CP 19, 18 및 17%로 처리하여 사용하였다. 육성 전기 실험 결과는 CP 수준이 증가함에 따라 체중, 증체량 및 사료 요구율이 유의적으로 개선되었지만(Linear effect, P<0.01), ME 수준과 $ME{\times}CP$ interaction에 의한 유의차는 나타나지 않았다. 균일도는 ME, CP 수준과 $ME{\times}CP$ interaction 모두에서 유의차가 나타나지 않았다. 육성 후기 실험 결과는 체중, 섭취량, 증체량, 사료 요구율 및 균일도에서 유의한 차이가 관찰되지 않았으나, 도체율에서는 ME 3,000 kcal/kg에서 유의적으로 가장 높게 나타났으며(Quadratic effect, P<0.01), ME와 CP의 수준이 증가함에 따라 간의 상대적 중량이 유의적으로 각각 작아지는 결과(Linear effect, P<0.01)가 나타났다. 가슴육, 넓적다리 및 북채의 상대적 중량에서는 수준간 유의적인 차이는 나타나지 않았다. 토종오리 고기의 화학 및 물리적 특성인 육색, pH, 가열 감량 및 전단력가에서는 ME 및 CP 수준과 $ME{\times}CP$ interaction 모두에서 유의차가 나타나지 않았다.

• Asian-Australasian Journal of Animal Sciences
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• 제27권7호
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• pp.1035-1043
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• 2014

To investigate the effect of dietary Acanthopanax senticosus polysaccharide (ASPS) on growth performance, immunity, blood parameters and mRNA expression of pro-inflammatory cytokines in immunologically challenged piglets, an experiment employing $2{\times}2$ factorial arrangement concerning dietary ASPS treatment (0 or 800 mg/kg) and immunological challenge (lipopolysaccharide [LPS] or saline injection) was conducted with 64 crossbred piglets (weaned at 28 d of age, average initial body weight of $7.25{\pm}0.21kg$) assigned to two dietary ASPS treatments with 8 replicates of 4 pigs each. Half of the piglets of per dietary treatment were injected with LPS or saline on d 14. Blood samples were obtained at 3 h after immunological injection on d 14 and piglets were slaughtered to obtain spleen samples on d 21. Dietary ASPS did not affect average daily gain (ADG) (p = 0.634), average daily feed intake (ADFI) (p = 0.655), and gain:feed (p = 0.814) prior to LPS challenge. After LPS challenge, for LPS-challenged pigs those fed ASPS had higher ADG and ADFI than the non-supplemented group (p<0.05), and an interaction between $LPS{\times}ASPS$ was observed on the two indices (p<0.05). Dietary ASPS improved lymphocyte proliferation among saline-injected and LPS-injected pigs (p<0.05). Interaction between $LPS{\times}ASPS$ was also revealed on lymphocyte proliferation (p<0.05). Circulatory concentration of IgG was influenced neither by ASPS (p = 0.803) or LPS (p = 0.692), nor their interaction (p = 0.289). Plasma concentration and spleen mRNA expression of interleukin-1beta (IL-$1{\beta}$), interleukin-6 (IL-6), and tumor necrosis factor (TNF)-${\alpha}$ were induced to increase (p<0.05) by LPS challenge, in contrast, these indices were decreased by dietary ASPS (p<0.05), and interactions were found on these cytokines (p<0.05). For LPS-challenged pigs, dietary ASPS also reduced the circulating concentration and spleen mRNA expression of IL-$1{\beta}$, IL-6 as well as TNF-${\alpha}$ (p<0.05). The interaction between $LPS{\times}ASPS$ was also observed on the circulating concentration of insulin-like growth factor-I, ${\alpha}$-acid glycoprotein (${\alpha}$-AGP), nonesterified fatty acid, and glucose (p<0.05). The results of this study demonstrate that dietary ASPS can modulate the release of pro-inflammatory cytokines during immunological challenge, which might enable piglets to achieve better growth performance.

• Asian-Australasian Journal of Animal Sciences
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• 제22권5호
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• pp.681-685
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• 2009

L-carnitine promotes mitochondrial ${\beta}$-oxidation of long chain fatty acids and their subsequent transport across the inner mitochondrial membrane. Although the role of L-carnitine in fatty acid metabolism has been extensively studied, its role in live performance and carcass responses of commercial broilers is less understood. The objective of this research was to determine if Lcarnitine fed at various levels in diets differing in CP and amino acids impacted on live performance and carcass characteristics of commercial broilers. Two floor pen experiments were conducted to assess the effect of dietary L-carnitine in grower diets. In Exp. 1, Ross${\times}$Hubbard Ultra Yield broilers were placed in 48 floor pens (12 birds/pen) and fed common diets to d 14. A two (0 or 50 ppm Lcarnitine) by three (173, 187, and 202 g/kg CP) factorial arrangement of treatments was employed from 15 to 35 d of age (8 replications/treatment). An interaction (p<0.05) in carcass yield indicated that increasing CP (187 g/kg) resulted in improved yield in the presence of L-carnitine. Increasing CP from 173 to 202 g/kg increased (p<0.05) BW gain and decreased (p<0.05) feed conversion and percentage abdominal fat. Feeding dietary L-carnitine increased back-half carcass yield which was attributable to an increase (p<0.05) in thigh, but not drumstick, yield relative to carcass. In Exp. 2, $Ross{\times}Ross$ 708 broilers were fed common diets until 29 d. From 30 to 42 d of age, birds were fed one of seven diets: i) 200 g/kg CP, 0 ppm L-carnitine; ii) 200 g/kg CP, 40 ppm L-carnitine; iii) 180 g/kg CP, 0 ppm L-carnitine; iv) 180 g/kg CP, 10 ppm L-carnitine; v) 180 g/kg CP, 20 ppm L-carnitine; vi) 180 g/kg CP, 30 ppm L-carnitine; and vii) 180 g/kg CP, 40 ppm L-carnitine (6 replications of 12 birds each). BW gain, feed conversion, mortality (30 to 42 d), and carcass traits (42 d) were measured on all birds by pen. There were no treatment differences (p<0.05). However, the addition of 40 ppm L-carnitine in the 200 g CP/kg diet increased (p = 0.06) thigh yields relative to BW in comparison to birds fed diets without L-carnitine, which was further confirmed via a contrast analysis (0 vs. 40 ppm L-carnitine in the 200 and 180 g CP/kg diets; p<0.05). These results indicated that dietary L-carnitine may heighten metabolism in dark meat of commercial broilers resulting in increased relative thigh tissue accretion without compromising breast accretion.

• 한국토양비료학회지
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• 제45권3호
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• pp.353-359
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• 2012

The identification of effective root zone would clarify dynamics of plant available water and soil water balance. Using the relationship between soil properties and electrical resistivity (ER) the purpose of this research is to identify soil zone affected by a plant root activity using electrical resistivity tomography (ERT) technique. Four plastic containers were prepared for two different soil textures (clay and sandy loam) and one container for each texture was selected for planting four corn seedlings (Zea mays L.) and the others were prepared for the blank. For ERT monitoring, we prepared 0.8 m plastic sticks with 17 electrodes installed with 5 cm space. The Ministing (AGI Inc., Texas) instrument for electrical resistivity measurement and semi-auto converter of electrode arrangement were set up for dipole-dipole array. During 2 months of the corns growing, ERT monitoring was made 3 to 4 days after the irrigation practice. Despite of the same amount water supplied into soils, two textures showed very different apparent resistivity values due to different clay content. The apparent electrical resistivity is consistently lower in clay loam comparing to sandy loam soil implying that plant root does not significantly alter the overall trend of resistivity. When plant root system, however, is active both soils with plants showed 2-7 times higher electrical resistivity and higher coefficient variation than soils without plant, implying the effect of root system on the resistivity, in which may caused by. This result suggests plant root activities regulating the soil water dynamics mainly control the variation of electrical resistivity over soil textural difference. Therefore the identification of water uptake zone would highly be correlated to plant root activities, thus ERT will be feasible approach to identify spatial characteristics of a plant root activity.

• Journal of Plant Biotechnology
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• 제41권2호
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• pp.100-106
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• 2014

희귀 식물 제주황기의 기내번식법 확립을 목적으로 줄기증식 및 발근을 시험하고 배양과정에서 나타나는 잎의 과수화 현상을 조직학적으로 조사하여 다음의 결과를 얻었다. 줄기유도 시 BA 및 kinetin의 처리는 다경유도 효과가 뚜렷하지 않았으며 대부분 단일 줄기로 자랐다. 하지만 BA 처리는 마디 수의 증가를, kinetin 처리는 줄기의 신장을 각각 촉진하는 효과가 있었다. 과수화(hyperhydration)된 잎은 정상 잎에 비하여 세포의 크기가 크고 책상조직의 발달이 부진하였으며, 세포의 배열이 불규칙하였다. 특히 과수화 잎의 세포는 세포 내 전분의 축적이 현저히 감소하는 것으로 나타났다. 기내발근은 세 가지 배지(B5, MS, WPM) 가운데 B5 배지가 양호하였으며, 0.1 mg/L IBA 처리 시 최고의 발근율을 보였다. 발근에 미치는 절편체 위치효과(정아지 혹은 액아지)는 통계적 유의 차가 없는 것으로 나타났다. 기외삽목 발근은 0.5% IBA 분말 처리로 65%까지 발근되어 기내발근 보다 저조하였으나, 차후 생존율은 더 좋은 것으로 나타났다. 이상의 결과는 제주황기의 기내번식이 가능함을 시사하며, 이 식물의 기내 및 기외보존의 방법으로 사용될 수 있음을 보여주었다.

• Asian-Australasian Journal of Animal Sciences
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• 제13권6호
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• pp.795-801
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• 2000

A total of 120 growing crossbred pigs ($Landrace{\times}Large$ $White{\times}Duroc$) with equal numbers of barrows and gilts were used in the feeding trial in a $2{\times}3$ factorial arrangement (gender by feeding regimens) to investigate the effect of phase feeding on growth performance during the 25 to 58 kg body weight growth stage, and 6 pigs (three of each sex) were used in a metabolic trial. The growing period was divided into two phases and 4 different CP diets were used to make 3 different feeding regimens (GE18-GL18; 18% CP diets for both early and later growing period, GE18-GL16; 18% CP diet for early and 16% CP diet for later growing period, GE19-GL17; 19% CP diet for early and 17% CP diet for later growing period). There were no significant differences in growth performance among treatments during the entire growing period. However, during the later growing period, feed intake of barrows was significantly higher than that of gilts (p<0.05). Average daily gain of barrows was higher than that of gilts (p>0.05). Based on the result, growth performance differences between barrows and gilts appeared to begin after 40 kg of body weight. There was no significant difference in digestibility among treatments or between sexes. During the early growing period the 18% CP diet showed better digestibility than the 19% CP diet. However, during the later growing period, the 18% and 17% CP diets exhibited similar digestibilities, although 16% CP diet showed slightly lower digestibility than 18% and 17% CP diets. During the early growing period, fecal N and P excretion of pigs fed the 19% CP were higher than that of those fed the 18% CP diet. During later growing period, fecal N and P excretion by those receiving the two phase feeding compared to single phase feeding was reduced by 10.2% and 2.0%, respectively. In the gilts, the cost reduction by two phase feeding (GE18-GL16) compared to single feeding was around 3.81%, but that of barrows was only 0.52%. The results suggested that the same nutrient levels could be applied to barrows and gilts during the growing period. Also, this study suggested the optimum protein and lysine level for early and later growing pigs to be 18% CP, 1.0% lysine and 16% CP, 0.8% lysine, respectively. Feeding two diets to growing pigs, i.e., two-phase feeding, would be more appropriate than feeding a single diet on economic and environmental considerations.