• 한국환경생태학회지
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• 제31권3호
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• pp.279-286
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• 2017

$CO_2$농도와 온도의 상승으로 인한 지구온난화가 진행되었을 때 광, 수분 그리고 유기물 구배에 따른 멸종위기식물인 황근의 생육과 생태적 지위폭의 변화를 알아보았다. 대조구(야외)와 처리구($CO_2$ + 온도 상승구)로 나누어 각각 광, 수분 그리고 유기물구배를 두어 재배하였다. 그 연구결과, 황근은 낮은 광량보다 높은 광량을 선호하나, 광량이 $787{\pm}77.76{\mu}mol\;m^{-2}s^{-1}$을 넘어가면 높은 광량이라 하더라도 생육이 어려웠다. 또한 유기물이 없거나(0%) 너무 많은 토양(20%)에서는 생육이 어려웠다. 그러나 수분 구배에 따른 경향이 보이지 않았다. 황근의 고사율은 대조구보다 처리구에서 광량이 높은 조건을 제외한 모든 구배에서 높았다. 이는 $CO_2$와 온도가 상승하면 광에 대한 내성범위가 좁아진다는 것을 의미한다. 대조구와 처리구를 비교하였을 때, 수분구배에 따른 경향은 보이지 않았다. 유기물구배에서는 대조구보다 처리구에서 모두 고사율이 낮았는데, 이는 유기물에 대한 내성의 범위가 넓어진 것을 의미한다. 황근의 생태적 지위폭은 처리구가 대조구보다 광 구배에서 30.1% 좁아졌으며, 수분 구배에서 8.6% 그리고 유기물 구배에서 30% 넓어졌다. 따라서 $CO_2$농도와 온도의 증가로 인한 지구온난화가 진행되면, 황근의 생육은 광량에 의해서 제한될 것으로 판단된다.

• 한국축산식품학회지
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• 제36권1호
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• pp.109-113
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• 2016

This study aimed to examine the nutrient utilization of rump round meat and lotus root using young (32 wk) and aged hens (108 wk) as an animal model. Rump round meat and lotus root were prepared with or without enzymatic treatment. For each age group of laying hens, a total of 24 Hy-Line Brown laying hens were randomly allotted to one of two dietary treatments with six replicates. For rump round meat, the true total tract retention rate (TTTR) of dry matter (DM) and nitrogen (N) were unaffected by either enzymatic treatment or hen age. However, aged hens had greater (p<0.01) TTTR of energy and crude fat than young hens. Enzymatic treatment did not influence the TTTR of energy or crude fat. In addition, we did not observe any significant interaction between the TTTR of DM, energy, N, or crude fat in rump round meat and hen age or enzymatic treatment. The TTTR of DM remained unchanged between controls and enzyme-treated lotus root for young hens. However, enzyme-treated lotus root exhibited greater (p<0.05) TTTR of DM than control lotus root for aged hens, resulting in a significant interaction (p<0.05). The TTTR of energy and N in lotus roots were greater (p<0.01) for aged hens than for young hens. In conclusion, enzymatic treatment exerted beneficial effects on energy and nutrient utilization in aged hens, suggesting the aged hen model is practical for simulation of metabolism of elderly individuals.

• 생물환경조절학회지
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• 제13권4호
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• pp.240-244
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• 2004

순환식 양액재배시 계면활성제가 무기이온 흡수 증진에 미치는 영향을 알아보고자 상추의 생육, 광합성율, 증산율 및 무기이온 함량을 분석하였다. 상추 생육은 $0.3mg{\cdot}L^{-1}$ PVA-95처리에서 가장 높았으며, l/2배액에서 재배된 상추의 생육도 양호하였다. 칼슘 함량이 증가된 $0.3mg{\cdot}L^{-1}$ CLS 처리의 상추는 생육이 낮음에도 불구하고 높은 증산율과 광합성율 및 엽내 카리, 칼슘 및 마그네슘 함량이 높았다. 따라서 높은 생육량과 비료 절감 효과가 인정된 PVA-95 처리와 CLS 처리에 의한 엽내 무기 성분 함량 증가가 인정됨에 따라 수경재배 상추의 고품질 생산에 유용하게 사용 가능하리라고 판단된다.

• 한국작물학회지
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• 제46권2호
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• pp.78-83
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• 2001

Two rice cultivars of the japonica type, ozone-resistant Ilpumbyeo (IL) and ozone-susceptible Keu-mobyeo#l (KM) were exposed to ozone ($O_3$) at 0.15 ppm for 30 days. The available nutrient regimes were varied by doubling the supply of nitrogen (N), phosphorus (P) and potassium (K) within a basic fertilizer status (N, P, K; 15, 12, 12 kg l0$a^{-1}$). There was little difference on plant height between ozone-treated and nontreated plants. The most significant ozone stress on tiller number was shown on the 30th day of ozone exposure. Slight recovery from ozone stress was noted on the 60th day. On the 30th day, tiller number was greatly decreased by 40.8% in IL and 64.6% in KM, whereas at a high nitrogen supply regime (2N), it was decreased by 21.4% in IL and 42.7% in KM as compared to the control not treated with ozone at basic fertilizer status. The inhibition of tiller production caused by ozone exposure was alleviated on the 60th day. In both cultivars, number of spikelets per plant and weight of 100 grains were affected little by the ozone treatment irrespective of nutrient regime. However, the number of panicles per plant and yield were reduced significantly. In both cultivars, yield of ozone-treated plants with 2N status was 12.4-16.1 % higher than that of the ozone-treated plants with basic nutrient status. A significant yield decrease of 47.8% and 33.4% was observed for IL and KM, respectively, in ozone-treated plants with higher potassium (2K) status.

• ALGAE
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• 제33권4호
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• pp.319-327
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• 2018

Ettlia sp. YC001, a highly settleable and productive microalga, was shown to be effective in removing nutrients and capturing suspended solids from eutrophic pond water. The optimum conditions for the Ettlia sp. YC001 cultivation were investigated using water from a landscape pond. The pond water was supplemented with different N : P ratios by weight, and the biomass production and nutrient removal compared in batch cultures. The maximum removal rate of N and P was with an N : P ratio of 16 : 1. Plus, the turbidity dropped to near zero within 4 days. Meanwhile, chemostat cultivation showed that the biomass productivity and nutrient removal rate increased when increasing the dilution rate, where a dilution rate of $0.9d^{-1}$ showed the highest N and P removal rate at $32.4mg\;L^{-1}\;d^{-1}$ and $1.83mg\;L^{-1}\;d^{-1}$, respectively, and highest biomass and lipid productivity at $0.432g\;L^{-1}\;d^{-1}$ and $67.8mg\;L^{-1}\;d^{-1}$, respectively. The turbidity was also reduced by 98% in the chemostat cultivation. Moreover, auto-flocculation and pH were closely connected to the turbidity removal. As a result, this study identified the optimal N : P ratio for small pond water treatment using an Ettlia sp. YC001, while also establishing the optimal conditions for nutrient removal, turbidity reduction, and biomass production.

• 농업과학연구
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• 제49권4호
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• pp.639-646
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• 2022

The present experiment was conducted to assess the effect of Buttiauxella-derived phytase in finishing pigs fed corn/soybean meal diets with an increase in the calcium (Ca)/total phosphorus (P) (Ca/tP) ratio and a reduction in net energy on the growth performance and nutrient digestibility on the finishing pigs. A total of 90 crossbred ([Yorkshire × Landrace] × Duroc) finishing pigs with an average initial body weight (BW) of 56.94 ± 2.43 kg were used for an 11-week feeding trial. The pigs were randomly allotted to one of three dietary treatments (six replication/treatment and five pigs/pen) in a randomized complete block design according to their BW and gender. Dietary treatments consisted of supplementation of phytase (0.05, 0.07, and 0.1% in the control, Trt1 and Trt 2 diets, respectively) maintaining the Ca/tP ratio (1.67 : 1, 1.84 : 1, and 2.19 : 1 in control, Trt1 and Trt 2 diets, respectively) and reducing the net energy by 1% in Trt1 and Trt2 diets compared with the control diet. The results showed that dietary supplementation with phytase in the energy-reduced diet had a similar (p > 0.05) effect on the BW, average daily gain, average daily feed intake, and gain/feed ratio of the finishing pigs. Also, there were no effects (p > 0.05) of treatment matrixes on the nutrient digestibility of dry matter, nitrogen calcium, phosphorus, and gross energy. In conclusion, the increase of phytase and Ca/tP ratio and the reduction of net energy in the corn/soybean meal diet resulted in comparable growth performance and nutrient digestibility of finishing pigs relative to pigs fed the control diet.

• 농업과학연구
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• 제49권1호
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• pp.45-50
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• 2022

The aim of this study is to evaluate the effects of supplementation of low-energy diets with PROSOL^® (sodium stearoyl-2-lactylate) as an emulsifier on the growth performance and nutrient digestibility of growing pigs. A total of 120 crossbred ([Landrace × Yorkshire] × Duroc) growing pigs with an average initial body weight of 23.80 ± 4.87 kg were used in a 56-day feeding trial and were sorted into three dietary treatments. Each treatment utilized eight replications with five pigs per pen. The dietary treatments were as follows: PC (high, net energy diet [NE] = 2,488 kcal·kg^-1 [weeks 1 to 4] and NE = 2,477 kcal·kg^-1 [weeks 5 to 8]); NC (low, NE = 2,472 kcal·kg^-1 [weeks 1 to 4] and NE = 2,468 kcal·kg^-1 [weeks 5 to 8]); NC1 (NC + 0.05% PROSOL^® emulsifier). Growth performance outcomes were measured at the initial point and at weeks 4 and 8 while nutrient digestibility parameters were measured at weeks 4 and 8. From weeks 1 - 8, body weight and the average daily gain of the NC1 group pigs showed significant increases (p < 0.05) compared to those of the PC and NC treatment groups. At the end of the trail, pigs fed a diet containing low net energy with 0.05% of the emulsifier showed reduced feed conversion ratio (FCR) levels. However, the average daily feed intake and nutrient digestibility of dry matter and nitrogen remained unaffected throughout the experiment. In summary, the addition of a low-net-energy diet with 0.05% sodium stearoyl-2-lactylate as an emulsifier enhanced the body weight and daily gain with no adverse effects on nutrient digestibility in growing pigs.

• 생물환경조절학회지
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• 제3권2호
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• pp.99-105
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• 1994

본 실험은 양액내 NO$_3$$^{-}$-N : NH$_4$$^{+}$-N 비율이 잎파(Allium fistulosum L.) 생육 및 품질에 미치는 영향을 알아보고자 실시하였으며, 그 결과는 다음과 같다. 양액내 pH는 NO$_3$$^{-}$-N : NH$_4$$^{+}$-N 비율이 9:1인 처리구에서는 상승하였고, NO$_3$$^{-}$-N : NH$_4$$^{+}$-N 비율이 1:1, 1:3인 처리구에서는 하강하는 경향이 있었으나, 3:1 처리구에서는 안정적인 PH를 유지하였다. 외관상 생육은 NO$_3$$^{-}$-N : NH$_4$$^{+}$-N 비율이 9:1인 처리구에서 가장 양호하였으며, NO$_3$$^{-}$-N : NH$_4$$^{+}$-N 비율이 1 :3인 처리구에서 가장 저조하였다. 식물체내의 NO$_3$$^{-}$-N의 함량은 양액내의 NO$_3$$^{-}$-N 비율이 높을수록 증가하였다. Pyruvic acid 함량은 생육이 양호한 NO$_3$$^{-}$-N : NH$_4$$^{+}$-N 비율이 9:1, 3:1인 처리구에서 높았으며, 1:3처리구에서는 낮았다.

• Journal of Ecology and Environment
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• 제38권3호
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• pp.293-305
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• 2015

In order to understand the mechanisms of conversion between different algal dominance, an experiment was performed in a greenhouse from 22 June to 10 July 2011. The experiment included a treatment group subjected to three instances of nutrient enrichment and a control with no nutrient enrichment. The initial water was dominated by Ankistrodesmus of Chlorophyta. The average water temperature at 08:30 h and 14:00 h during the experiment was $31.6^{\circ}C$ and $34.6^{\circ}C$, respectively. The results showed that the total nitrogen (TN), total phosphorus (TP), dissolved total nitrogen (DTN), dissolved total phosphorus (DTP), and soluble reactive phosphorus (SRP) concentrations in the treatment were significantly higher than in the control (P < 0.05). However, the TN/TP and DTN/DTP in the control was higher than in the treatment (P < 0.05). The dominant algae in the control did not change during the experiment, while the dominant algae in the treatment switched to Planktothrix of Cyanophyta on day 9. The chlorophyll a (Chl-a), wet weight of all algae, wet weight of Cyanophyta, and percentage of Cyanophyta in the control were all significantly lower than in the treatment (P < 0.05). Amounts of zooplankton, especially rotifers, were present at the end of the experimental period. The density of rotifers between the control and treatment was not significantly different (P > 0.05), while the copepod density in the treatment was higher than in the control (P < 0.05). We conclude that green algae dominance quickly switches to cyanobacteria dominance after nutrient enrichment in a greenhouse with elevated temperature.

• Asian-Australasian Journal of Animal Sciences
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• 제30권10호
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• pp.1435-1441
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• 2017

Objective: The objective of this study was to determine the effect of adding water to total mixed ration (TMR) on fresh water intake, nutrient digestibility, wool cortisol, and blood indices in Corriedale ewes under hot and humid conditions. Methods: Nine non-pregnant Corriedale ewes (ave. body weight = $41{\pm}3.5kg$) were individually fed diets based on maintenance requirements in metabolic crates. Ewes were assigned to three treatment groups according to a triplicate $3{\times}3$ Latin Square design for 3 periods of 21 days duration each (9 ewes per treatment, 27 replications). Treatments were TMR (crude protein [CP] = 16.1, total digestible nutrients = 69.1%) moisture levels for 40%, 50%, and 60%. Results: No differences were found in body weight gain among all treatment groups (p>0.05). Nitrogen balance including digestible N, retained N, and urinary and fecal N showed no change among the treatment groups (p>0.05). Fresh water intake was the lower in 50% TMR moisture group than in the other groups (p<0.05). Other than ether extract which was higher in 60% TMR moisture group (p<0.05) the differences among nutrient digestibilities including CP, organic matter, dry matter, neutral detergent fiber, acid detergent fiber, and non-fiber carbohydrate were not significant (p>0.05). No significant difference was observed for serum protein, blood urea nitrogen, glucose, and triglyceride among the treatment groups (p>0.05). Wool and blood cortisol were not different among the treatment groups (p>0.05). Blood hematology including red blood cell, white blood cells, hemoglobin, hematocrit, basophils, and eosinophils were not different among the treatment groups (p>0.05). Conclusion: It is concluded that TMR moisture at 40%, 50%, and 60% had no effects on N balance parameters, and nutrient digestibilities except for the ether extract under hot and humid conditions. Additionally there were no effects on stress conditions include wool cortisol, as well as blood cortisol levels of ewes.