• 한국유기농업학회지
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• 제20권3호
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• pp.369-383
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• 2012

사육밀도를 달리 했을 때 지렁이 개체군의 생체량 증가를 위한 최적 사육밀도를 추정하려고 하였다. 실험결과를 요약하면 다음과 같다. 1. 사육밀도 S-2과 S-3에서 상대증체량, 생체중 증가율과 유기물 전환효율이 높은 값을 나타내어, 지렁이 개체군의 최대 생체량을 얻기 위한 최적 사육밀도로 추정되었다. 이를 지렁이 생체중과 먹이량의 비율로 나타내면 1:32-1:48의 범위였다. 2. 사육밀도 S-1(1:16)에서 모든 조사시기의 분립생산량이 유의하게 많았고 분립비율도 유의하게 높았다($$P{\leq_-}0.05$$). 3. 사육밀도 S-3(1:48)에서 지렁이 생체중당 난포수와 분립생산량이 가장 많았다($$P{\leq_-}0.05$$). 4. 사육밀도가 높아지고 사육기간이 길어짐에 따라 분립의 전 질소함량, 유효인산함량, 양이온치환능력(CEC) 및 양이온 함량이 증가되는 경향이었다. 5. 유기농업에서 지렁이 분립은 상토 재와 토양개량제 및 작물보호를 위한 농자재로서 잠재적 유용성은 매우 높다고 판단된다.

• 수산경영론집
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• 제42권2호
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• pp.85-96
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• 2011

Oliver flounder population density affect Oliver flounder growth and mortality rate. In laboratory pilot experiment, Oliver flounder growth rate is inversely proportional to stocking density. But previous study has not proved external validity. This study is aimed to analyze the effect of stocking density on the Oliver flounder culture farms in Jeju Island. In order to do this, I selected 13 farms in Jeju island as a sample. In the study, various analytical methods including productivity analysis, regression analysis, statistical analysis were conducted for 13 Oliver flounder culture farms. The result of analysis can be summarized as follows. First, in case of the Oliver flounder culture farms, Bertalanffy equation is not applicable to the Oliver flounder growth. Second, the Oliver flounder stocking density, defined as the surface area of Oliver flounder per $m^2$ of water surface area, is preferred to density definition defined as the weight of Oliver flounder per $m^2$ of water surface area on the Oliver Flounder Culture Farms case. Third, growth rate and production weight on the Oliver flounder culture farms are inversely proportional to stocking density on spearman rank correlation test. When extensive comparable biological and culture condition data become available, analysis model can be easily modified to yield more accurate results.

• Asian-Australasian Journal of Animal Sciences
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• 제4권3호
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• pp.255-262
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• 1991

The effects of S fertilization and stocking rate on cattle production from native and sown pastures were studied in South Sulawesi, Indonesia. On the native pasture there was no effect of S application over the three years of the experiment. The per head production was lower at the higher stocking rate (1.0 hd/ha), but the overall production increased by an average of 49%. There was no response to S applied to the clean seedbed pastures in the first year, but significant responses developed in the second and third years. There was an overall higher production from the higher stocked pastures (3.0 hd/ha), but the per head production was lower. There was a mean of about a two-fold increase in animal production from the highest native to the lowest improved pasture and a 3.4 times increase from the low stocking rate native to the high stocking rate sown pasture.

• Asian-Australasian Journal of Animal Sciences
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• 제19권4호
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• pp.514-520
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• 2006

An abandoned mandarin orange orchard in southwestern Japan was set-stocked by Japanese Black cows at two stocking rates (1.0 and 2.0 animals/ha), and vegetation dynamics and diet selection by cattle were monitored for two years, in an effort to obtain information on effective use of abandoned agricultural fields for low-cost animal production and environmental conservation. Two dominant species at the commencement of grazing, kudzu (Pueraria lobata Ohwi) and tall goldenrod (Solidago altissima L.), showed different responses to grazing during the two years; the composition of kudzu decreased, contrasting with that of tall goldenrod which increased at both stocking rates. This was caused by high preference for kudzu and avoidance or low preference for tall goldenrod by cattle. Retrogression of vegetation due to cattle disturbances occurred at both stocking rates, with the high stocking rate leading to a lower degree of succession than the low stocking rate. It was shown that cattle grazing, particularly at a high stocking rate, was effective in the management of vegetation of an abandoned orchard.

• 한국축산시설환경학회지
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• 제18권2호
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• pp.63-74
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• 2012

사육밀도의 차이가 지렁이의 생육, 체조직으로의 유기물 전환효율 및 분립생산량에 미치는 영향을 조사한 결과를 요약하면 다음과 같다. 1. 공시 한우분의 탄질율은 25.1로, 지렁이 먹이로 적합한 탄질율로 추정되었다. 2. 지렁이 생체중과 먹이 량의 비율이 1:32였던 S-3에서 생체중 증가율과 체조직으로의 유기물 전환효율이 유의하게 높은 값을 나타내었는데, 이 비율을 사육공간으로 나타내면 $56.6cm^3$이었다. S-3에서 사육기간 평균 생체중 증가율과 체조직으로의 유기물 전환효율은 각각 10.63 mg/day와 6.65%를 나타내었다. 3. 지렁이 생체중과 먹이 량의 비율 1:8이었던 S-1에서 사육기간 중 분립비율이 가장 높았지만, 생체중 증가율과 체조직으로 유기물 전환효은 -값을 나타내었다. 이는 개체 간 먹이 경합이 심해진 결과로 추정된다. 4. 사육밀도가 높아짐에 따라 지렁이 분립의 pH, 전 질소함량, 유효인산함량, 양이온치환능력 (CEC) 및 양이온 함량이 유의하게 증가되었다. 특히 유효인산함량, 양이온치환능력 및 양이온함량은 사육기간이 길어짐에 따라 유의하게 증가되었다. 5. 지렁이 분립의 이화학적 특성으로 볼 때, 상토 재 또는 토양개량제로서 유용성이 높다고 판단되었다.

• 한국양식학회지
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• 제7권1호
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• pp.9-20
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• 1994

전복을 육상에서 사육하기 위한 시설형태 및 적절한 사육밀도의 구명을 위해 수조형태 및 수용밀도별 사육실험을 한 결과 1. 수조형태, 단별에 따른 성장과 생존율의 차리는 인정되지 않았고, 유수식과 순환식사육의 비교에서는 유수식의 성장도와 생존율이 좋았다. 2. 수조단수별 (3단)에 따른 성장과 생존율의 차이가 인정되지 않아 동일량의 사육수로 단위면적 당 3배의 생산이 가능하였다. 3. 밀도별실험에서 $1000-2000마리/m^2$로 수용한 각장 약 20mm치패는 수용밀도에 따른 성장 차가 없었지만, 각각 200-600, 100-300마리의 밀도로 수용한 각장 약 40mm와 50mm의 치패는 수용밀도가 낮을수록 성장이 빨랐다. 4. 일간섭식률과 사료전환효율은 밀도가 낮을수록 높았고, 치패 크기가 작을수록 높았다

• 수산경영론집
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• 제45권2호
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• pp.85-95
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• 2014

Fish stocking is important element of land-based aquaculture management. To maintain constant stocking rate considering biological and economic condition is a convenient strategy in intensive aquaculture. This study is aimed to analyze the effect of over-stocking(more than aquaculture capacity) for certain periods of time. This study make the mathematical decision making model that finds the value of decision variable to minimize cost that sums up the water pool usage cost and sorting cost under critical standing corp constraint. The proposed mathematical decision making model was applied to 12 sample combination of sorting cost and the number of fish on the Oliver flounder culture farms. If a immature fish can be sold for high price than farming cost, restricted over-stocking resulted in a improvement of economic performance. When extensive comparable biological and market data become available, analysis model can be widely applied to yield more accurate results.

• 수산경영론집
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• 제42권3호
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• pp.79-93
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• 2011

Water temperature of Oliver flounder farm affects Oliver flounder growth and mortality rate. In laboratory experimental tanks, optimal water temperature was $22.5^{\circ}C$($21{\sim}24^{\circ}C$) and cultivatable water temperature was $12{\sim}28^{\circ}C$. The purpose of this study is to identify applicable and useful water temperature of Oliver flounder farm in case of actual farming. The data applied in the analysis was collected from Jeju island. In the study, various analytical methods including productivity analysis, regression analysis, statistical analysis were conducted for 13 Oliver flounder culture farms. The result of analysis can be summarized as follows : First, growth rate on the Oliver flounder culture farms was related to mean of water temperature, variation of water temperature and low water temperature. Second, survival rate on the Oliver flounder culture farms was related to mean of water temperature. In case of including Oliver flounder stocking density, defined as the surface area of Oliver flounder per $m^2$ of water surface area, survival rate strongly related to mean of water temperature, variation of water temperature, cultivating capability and stocking density. Third, production weight per $m^2$ of water surface area was strongly related to mean of water temperature, low water temperature and cultivating capability. Growth rate and survival rate was analyzed into mediate variable character.

• 한국패류학회지
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• 제28권1호
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• pp.1-6
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• 2012

2002년 6월부터 2003년 10월까지 충남 태안군 안면읍 내파수도 연안의 수하식 양식장에서 비단가리비 치패 (평균 각고 $32.97{\pm}6.21mm$, 전중량 $5.63{\pm}3.86g$) 를 채롱에 수용하여 밀도에 따른 성장과 생존을 연구하였다. 비단가리비는 주로 한국의 서해안과 중국의 북부 연안에 자연적으로 서식하는 종이다. 조사해역의 표층 수온은 $4.3-25.3^{\circ}C$, 염분은 29.2-32.1 psu, 용존산소는 5.32-7.51 mg/L이었고, pH는 7.84-8.12로 나타났다. 실험을 시작할 때 채롱 당 수용밀도는 20, 30, 40, 50 개체로 하였다. 실험을 시작하여 16개월이 경과한 후의 평균 각고는 64.35-76.23 mm였고, 전중량은 41.53-64.85 g, 생존율은 82-100%로 나타났다. 비단가리비의 성장률은 수용밀도와 역상관 관계를 가지고 있었다. 각고와 전 중량의 성장은 수온이 하강하면서 감소하였다. 비단가리비의 폐사는 대부분 3-4월과 9-10월에 나타났다. 밀도에 따른 생존율은 밀도가 증가함에 따라 감소하였으며 20마리 실험구에서 가장 높게 나타났다.

• 수산해양기술연구
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• 제53권1호
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• pp.49-59
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• 2017

The objective of this study was to investigate the growth rate and the optimal stocking density of sea cucumbers. Grow-out was studied in situ by conducting a follow-up survey using visible implant elastomer (VIE) tags. The rearing systems were made of polypropylene pipe for the frames and netting. The experiment ran for 70 days near Yeosu, Korea in the water depth of about 7 m. A total of 576 sea cucumbers which have three groups of body sizes (small: 5.15, medium: 12.34 and large: 23.26 g) were used. The five groups of stocking densities (150, 300, 450, 600 and $850g/m^2$) in rearing system for sea cucumber were considered. Sea cucumbers were fed a mixed diet (mud, mineral, fish meal, etc.). The feed was supplied to 10% of their body wet weight once every 7 days. The survival rate (73%) of sea cucumber in $850g/m^2$ was lower than those of other density groups ($150g/m^2$: 89%, $300g/m^2$: 84%, $450g/m^2$: 78% and $600g/m^2$: 86%). The survival rate of medium size group was higher than those of small and large groups regardless of the density (P<0.05). Most of density groups have no significant difference except for $850g/m^2$ (P>0.05). The growth rate of small size group ($0.63%day^{-1}$) was higher than those of medium ($0.38%day^{-1}$) and large ($0.34%day^{-1}$) group regardless of the density (P<0.05). The threshold water temperature was $11.0^{\circ}C$ for sea cucumber growth in winter season.