• Asian-Australasian Journal of Animal Sciences
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• 제30권5호
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• pp.660-665
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• 2017

Objective: The objective of the study was to determine the effects of increasing levels of metabolizable protein (MP) on lactation performance and nitrogen (N) efficiencies in lactating dairy cows. Methods: Nine multiparous cows in mid lactation [$113{\pm}25$ days in milk] received three treatments in a $3{\times}3$ Latin square design with a period length of 21 days. The treatments were three diets, designed to provide similar energy and increasing supply of MP (g/d) (2,371 [low], 2,561 [medium], and 2,711 [high] with corresponding crude protein levels [%]) 15.2, 18.4, and 20.9, respectively. Results: Increasing MP supplies did not modify dry matter intake, however, it increased milk protein, fat, and lactose yield linearly. Similarly, fat corrected milk increased linearly (9.3%) due to an increase in both milk yield (5.2%) and milk fat content (7.8%). No effects were observed on milk protein and lactose contents across the treatments. Milk nitrogen efficiency (MNE) decreased from 0.26 to 0.20; whereas, the metabolic efficiency of MP decreased from 0.70 to 0.60 in low to high MP supplies, respectively. The concentration of blood urea nitrogen (BUN) increased linearly in response to increasing MP supplies. Conclusion: Increasing MP supplies resulted in increased milk protein yield; however, a higher BUN and low MNE indicated an efficient utilization of dietary protein at low MP supplies.

• 한국토양비료학회지
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• 제18권2호
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• pp.208-214
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• 1985

수원지방(水原地方)의 농가포장(農家圃場)에서 1978년(年)~83년(年) (6개년(個年)) 식양토(埴壤土)인 보통답(普通畓)에서 수도품종별(水稻品種別) 질소(窒素) 시비반응(施肥反應) 및 질소(窒素) 생산효율(生産效率) 등(等)을 검토(檢討)하였는바 그 결과(結果)를 요약(要約)하면 다음과 같다. 1. 2차회귀식(次回歸式)을 적용(適用), 최다수량(最多收量)을 생산(生産)하기 위(爲)한 질소시비(窒素施肥) 최적량(最適量)은 13.9g~28.0kg/10a 범위(範圍)로 품종(品種)에 따라 차이(差異)가 크므로 질소내비성(窒素耐肥性)을 고려(考慮)하여 품종(品種)을 선정(選定), 재배(栽培)함이 필요(必要)하였다. 2. 질소(窒素) 시비최적량(施肥最適量)이 높았던 품종(品種)에서는 수확기(收穫期) 질소함량(窒素含量)(경엽(莖葉)) 및 총질소(總窒素) 흡수량(吸收量)(경엽(莖葉)+곡실(穀實))이 증가(增加)하였으나 최적량(最適量) 시용시(施用時) 시비(施肥) 및 흡수질소(吸收窒素)의 생산효율(生産效率)과 질소이용율(窒素利用率)은 오히려 감소(減少)하였다 3. 품종별(品種別) 무질소구(無窒素區) 정조수량(正租收量)에 대(對)한 질소(窒素) 최적량(最適量) 시용시(施用時) 정조수량(正租收量)의 증수효과(增收效果)를 증수율(增收率)로서 볼 때 29~121%의 범위(範圍)로서 품종간(品種間) 질소응수(窒素應酬)의 차이(差異)가 현저(顯著)하였다. 4. 질소(窒素) 최적량(最適量) 시용시(施用時) 질소응수(窒素應酬)가 큰 품종(品種)은 수확기(收穫期) 총질소(總窒素) 흡수량(吸收量), 시비(施肥) 및 흡수질소(吸收窒素)의 생산효율(生産效率)과 질소이용률(窒素利用率)이 높았다.

• 한국환경농학회지
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• 제30권2호
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• pp.138-143
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• 2011

본 연구는 탄질비가 다른 유기자재를 시용하였을 때 유기재배 벼의 수량과 질소이용율이 미치는 기상 조건의 영향을 조사하기 위해서 2010년에 수행되었다. 처리구는 질소함량 9kg/10a 수준으로 화학비료, 가축분퇴비, 유박1배, 유박2배 (18 kg/10a), 헤어리베치, 베치+호밀을 포함하였다. 유박과 헤어리베치는 가장 낮은 탄질비를 나타내었고 가축분퇴비는 34 : 1의 가장 높은 탄질비를 보였다. 유기자재 처리구의 초기 생육은 양호하였으나 후기 태풍과 같은 기상조건에 따라 전반적으로 생육이 부진하고 수량이 감소하였다. 특히, 유박2배구는 초기생육이 월등하였으나 태풍의 영향으로 도복정도가 가장 심하게 나타났다. 탄질비가 높은 가축분퇴비구는 정상적인 질소공급이 이루어지지 않아 초기생육이 불량하였고 도복하지 않았더라도 낮은 수량을 보였다. 질소흡수량은 유박2배와 베치+호밀구에서 높았고 가축분퇴비에서 가장 낮았으며, 질소이용율도 비슷한 경향을 나타내었다.

• 한국유기농업학회지
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• 제26권4호
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• pp.731-743
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• 2018

배추 유기재배 시 녹비작물과 추비방법이 배추의 생육과 질소이용에 미치는 영향을 구명하기 위하여 2012년부터 2014년까지 수원에 있는 국립농업과학원 포장에서 시험을 수행하였다. 녹비작물은 여름철 크로타라리아와 겨울철 헤어리베치를 이용하였다. 녹비처리 방법은 전면경운 토양혼입방법과 부분경운 토양혼입방법, 그리고 무경운 예취피복처리를 비교하였다. 추비방법은 녹비만 처리한 것과 녹비 처리 후 유박과 액비로 추비한 처리를 비교 하였다. 시험결과 녹비 처리 방법은 예취 후에 경운하여 토양혼입 하는 것보다 무경운 피복처리 하는 것이 좋았다. 봄배추재배 시 동계 녹비작물 헤어리베치 재배로 정상적인 생육과 수량이 가능하였고 관행의 화학비료 처리구에 비하여 무름병과 Tip-burn 발생이 적어 수량성도 높았다. 가을재배에서는 녹비 연속재배와 유박 추비로 관행의 화학비료처리구와 비슷한 수량을 보였다. 하지만 하계 단기성 녹비작물 재배 시에는 관행 수량의 70% 내외에 그쳤다. 녹비재배에 이은 액비 활용 양분관리로 관행과 비슷한 수량이 가능하였고 토양중 무기태 질소가 안정적으로 유지되고 질소이용효율도 향상되었다. 결론적으로 배추 유기재배를 위해서는 겨울과 여름 녹비작물을 재배하고 가을 작기를 선택하여 액비로 추비하는 것이 권장된다.

• 유기물자원화
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• 제30권4호
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• pp.27-40
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• 2022

본 연구에서는, 탈수슬러지 및 음식물류폐기물의 효율적인 병합혐기성소화를 위해 폐기물의 혐기성소화 가능성 및 열화학적 전처리 방법에 대해 평가하였다. 폐기물의 혐기성소화 가능성 평가 결과, 음식물류폐기물이 탈수슬러지에 비해 혐기성미생물에 의해 분해 가능한 유기물 농도 및 methane yield가 각각 2.2배, 1.3배 더 높게 평가되었다. 바이오가스 발생량의 증대를 위해서는, 음식물류폐기물의 혼합비율을 증가시키는 것이 필요할 것으로 판단되었으며, 열화학적 전처리 효율은 반응온도, NaOH 주입량, 반응시간, 혼합비율 조건에 대해 평가하였다. 전처리 효율 및 탈수능을 통해 평가한 결과, 최적 열화학적 가용화 전처리 조건은 반응온도 140℃, NaOH 주입량 60 meq/L, 반응시간 60 min, 혼합비율 1:5로 평가되었다. 최적 열화학적 가용화 전처리 조건 적용 전과 후의 methane yield를 비교한 결과, 전처리를 적용한 경우에서, 가스발생속도 및 methane yield가 각각 1.6, 1.5배 증가하였다. 따라서, 탈수슬러지 및 음식물류폐기물의 효율적인 병합혐기성소화를 위해서는 음식물류폐기물의 혼합비율을 증가시키며, 폐기물의 전처리를 통해 가용화 효율을 증대시키는 것이 필요하다고 판단된다.

• 에너지공학
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• 제24권4호
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• pp.11-17
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• 2015

본 연구에서는 음식물류 폐기물 폐수(이하, 음폐수)를 이용하여 혐기성발효 시 부산물로 생성되는 메탄가스의 생산효율을 높이고자 산발효 전처리를 수행하였으며 전처리된 음폐수를 이용하여 BMP 실험을 통해 메탄생산량 증대를 위한 산발효 최적조건을 확인하고자 하였다. 산발효된 음폐수를 이용하여 BMP 실험을 진행한 결과 HRT 3일 조건에서 0.220 L/g VS의 가장 높은 메탄생산량을 확인하였으며, 초기 pH별 BMP실험에서는 pH 6에서 19,920 mg/L로 가장 높은 VFA와 Acetic acid/TVFA(76.2%)를 보였다. 이때 메탄생산은 약 10일 이내로 대부분 생산되어 일반적인 메탄발효(30일 이내)에 비해 약 1/3수준으로 단축됨을 확인하였다. 메탄생성량은 0.294 L/g VS로 대조군 대비 약 1.3배 높은 효율을 나타내었다.

• Mycobiology
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• 제35권3호
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• pp.135-144
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• 2007

The removal efficiency of the heavy metals Zn, Pb and Cd by the zoosporic fungal species Saprolegnia delica and the terrestrial fungus Trichoderma viride, isolated from polluted water drainages in the Delta of Nile in Egypt, as affected by various ranges of pH values and different temperature degrees, was extensively investigated. The maximum removal efficiency of S. delica for Zn(II) and Cd(II) was obtained at pH 8 and for Pb(II) was at pH 6 whilst the removal efficiency of T. viride was found to be optimum at pH 6 for the three applied heavy metals. Regardless the median lethal doses of the three heavy metals, Zn recorded the highest bioaccumulation potency by S. delica at all pH values except at pH 4, followed by Pb whereas Cd showed the lowest removal potency by the fungal species and vice versa in case of T. viride. The optimum bio-mass dry weight production by S. delica was found when the fungus was grown in the medium treated with the heavy metal Pb at pH 6, followed by Zn at pH 8 and Cd at pH 8. The optimum biomass dry weight yield by T. viride amended with Zn, Pb and Cd was obtained at pH 6 for the three heavy metals with the maximum value at Zn. The highest yield of biomass dry weight was found when T. viride treated with Cd at all different pH values followed by Pb whilst Zn output was the lowest and this result was reversed in case of S. delica. The maximum removal efficiency and the biomass dry weight production for the three tested heavy metals was obtained at the incubation temperature $20^{\circ}C$ in case of S. delica while it was $25^{\circ}C$ for T. viride. Incubation of T. viride at higher temperatures ($30^{\circ}C\;and\;35^{\circ}C$) enhanced the removal efficiency of Pb and Cd than low temperatures ($15^{\circ}C\;and\;20^{\circ}C$) and vice versa in case of Zn removal. At all tested incubation temperatures, the maximum yield of biomass dry weight was attained at Zn treatment by the two tested fungal species. The bioaccumulation potency of S. delica for Zn was higher than that for Pb at all temperature degrees of incubation and Cd bioaccumulation was the lowest whereas T. viride showed the highest removal efficiency for Pb followed by Cd and Zn was the minor of the heavy metals.

• 한국양식학회:학술대회논문집
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• 한국양식학회 2003년도 추계학술발표대회 논문요약집
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• pp.38-38
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• 2003

Blocking the first mitotic cleavage of the zygote is a key tool for chromosome-set manipulations in fish. We developed an improved method for inducing tetraploidy by blocking the mitosis with a combination of heat shock at 40.5$^{\circ}C$ for 1, 2 or 3 min followed by cold shock at $1.5^{\circ}C$ for 30, 45 or 60 min. When applied during the first cleavage metaphase of mud loach (Misgurnus mizolepis) zygotes, the optimal combination was heat for 2 min followed by cold for 45 min. At 1 month, the frequency of 4N survivors and the yield from total eggs fertilized was 55.7% and 14.4%, respectively, compared to heat shock alone with 20.0% efficiency and 3.6% yield. The effectiveness of the procedure was confirmed by diploid mitotic gynogenesis using transgenic markers. The overall yield of homozygous diploids, 34.0%, was better than that for single heat shock, 17.3%. The tetraploids and homozygous diploids had higher early mortality than normal diploid controls. However at 1 month, the viability of the tetraploids was the same as normal diploids. For gynogenetic diploids, the survival was similar to normal diploids after 3 months. The high efficiency of this new protocol extends the opportunity to study polyploidy in basic and applied research.

• 펄프종이기술
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• 제33권2호
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• pp.58-67
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• 2001

MOW (Mixed Office Waste) mainly consisted of photocopied paper is being recycled to produce tissue or fine paper products. Toner particles that are fused and set on paper surface in photocopying process turns into large and plate-shaped particles after repulping which prevents them to be removed effectively in flotation deinking. The immediate purpose of this study is to find the effective deinking technology that increases the recycling potential of photocopied papers for manufacturing tissue and fine paper products. In this study the effects of pulping temperature and the type of hydrophobic groups of nonionic surfactants on the deinking efficiency of photocopied paper has been investigated. Particle size distribution of the toner particles after pulping and flotation, brightness, yield and ash removal were investigated. The size of toner particles after pulping increased as the pulping temperature was increased. When pulping at the low temperature finer toner particles were generated, however, greater amount of toner particles was found to attach to the fiber. When the pulping temperature was greater than Tg of the toner, the amount of coarse hairy particles increased. When nonionic surfactants with a double bond in hydrophobic groups were used, toner removal efficiency, brightness and ash removal were increased. As the addition level of surfactant was increased, yield decreased rather sharply without improving brightness.

• Asian-Australasian Journal of Animal Sciences
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• 제14권10호
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• pp.1409-1418
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• 2001

Two trials were carried out during two different grazing seasons to evaluate effect of grass silage supplementation, when amount of pasture is limited on dry matter intake (DMI), milk production, and gross energetic efficiency (GEE) of grazed lactating cows on a high forage-based diet. Fifty-one Holstein cows were randomly assigned to one of two dietary treatments: high pasture group or high silage group. In the spring flush, pasture and silage DMI, milk yield, milk fat percentage, and GEE were not different between the dietary groups. After the spring flush, pasture and silage DMI were higher for the high silage group than for the high pasture group. After the spring flush, although these were the higher total DMI of the high silage group than the high pasture group, milk yield was significantly (p<0.05) higher for the high pasture group than the high silage group. Milk fat percentage tended to be higher for the high silage group than the high pasture group. The GEE was significantly (p<0.05) higher for the high pasture group than the high silage group during after the spring flush. This study indicated that supplementation of grass silage, especially after the spring flush, can have a significant effect of increasing of forage intake and maintenance of the milk fat percentage; but not increase milk yield and GEE.