• 한국발생생물학회지:발생과생식
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• 제15권2호
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• pp.77-85
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• 2011

본 연구는 황복, T. obscurus 치어(TL $25.0{\pm}0.5$ mm, BW $0.53{\pm}0.03$ g)의 초기 생활사 동안 성장, 생존 및 공식행위에 있어 밀도와 먹이 공급횟수(공급량)의 관련성을 구명하기 위해 밀도와 먹이제한 조건에서 일렬의 실험을 실시하였다. 실험기간 중 실험 밀도는 1.43 inds./${\ell}$, 2.14 inds./${\ell}$, 2.86 inds./${\ell}$, 3.57 inds./${\ell}$, 4.29 inds./${\ell}$ & 7.14 inds./${\ell}$와 같이3반복으로 6개의 실험구를 설정하여 주었고, 먹이 공급은 1~15일까지 3회/일, 16~30일까지는 1회/일로 횟수를 제한하였다. 실험은 1톤 수조에서 30일간 실시되었다. 실험기간 동안, DFI, FE, 성장, 공식빈도, 공식 폐사율(생존율)을 조사하였다.DFI와 FE는 밀도에 따른 어떠한 경향도 보이지 않았다. 공식 빈도와 폐사율은 밀도가 증가하고, 먹이 공급횟수가 감소할수록 유의하게 증가하였다. 그에 따른 생존율은 밀도가 증가할수록 유의하게 감소하는 경향이 있었다. 결론적으로 군집밀도는 공식 행위와 정상관계를 보였지만, 먹이량은 공식과 역상의 관계를 지니고 있음을 확인할 수 있었다.

• 한국수산과학회지
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• 제18권5호
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• pp.491-495
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• 1985

1984년 11월 2일부터 1985년 2월 3일까지 부산수산대학 어류양식 연구실에서 평균 73.3g 및 26.7g되는 이스라엘잉어 각각 15미(총중량 1,100g및 400g)씩을 수용하고, 우리 나라에서 질이 우수하다고 인정되고 있는 상품사료와 $40\%$ 대두박분 대체사료를 대조구 사료로 하고, 인산일수소나트륨($Na_{2}HPO_{4}{\cdot}12H_{2}O$)을 $2\%$ 첨가하여 만든 인첨가 $40\%$ 대두박분 대체사료를 실험사료구로 하여 사료효율 시험을 하였다. 상품사료에서는 큰 개체군과 작은 개체군에서 각각 사료계수 1.340, 1.368, 1일 성장률 $1.696\%,\;1.708%$로 나타났고, 인첨가 $40\%$ 대두박분 대체사료에서는 사료계수 1.431, 1.558, 1일 성장율 $1.619\%,\;1.589\%$로 성장률이 상품사료에 비해 약간 떨어지기는 했지만 거의 비슷한 결과를 나타내었다. 그런데 $40\%$ 대두박분 대체사료는 사료계수 1.863, 1.820, 1일 성장률 $1.365\%,\;1.438\%$로 성장률이 크게 뒤떨어진 결과를 나타내었다. 그러므로 이상의 실험결과에 의하면 $40\%$ 대두박분 대체사료는 잉어의 사료로서는 적절하지 못했지만, 이에 적당량의 인을 첨가하게 되면 우수한 사료로 될 수 있다는 것을 밝혀주고 있다.

• 한국작물학회지
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• 제44권4호
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• pp.330-338
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• 1999

Extensive research has been conducted on effects of drought stress on growth and development of soybean but information is rather restricted on the limited-irrigation system by way of precaution against a long-term drought condition in the future. The experiment for limited-irrigation was conducted in transparent vinyl shelter at Asian Vegetable Research and Development Center (AVRDC), Taiwan in 1997. Two soybean varieties, Hwangkeum and AGS292, improved in Korea and AVRDC, respectively were used for this experiment. The relationships between normalized transpiration rate (NTR) and fraction of transpirable soil water (FTSW) in both varieties were similar that the NTR was unchanged until FTSW dropped to about 0.5 or 0.6. At FTSW less than those values, NTR declined rapidly. Days required to harvest in both varieties were significantly prolonged at IR6 treatment compared to any other treatments. Daily mean transpiration rate was significantly higher at IR5 treatment, as averaged over varieties. Similarly, water use efficiency was also high at 1R5 treatment. In both varieties, seed yield was the greatest at the IR5 treatment, as compared to any other limited-irrigation treatments, due to the increased seed number and high transpirational water use efficiency. The indices of input water and seed yield for the different limited-irrigation treatments against control indicated that Hwangkeum produced 59.6% or 60.7% of seed yield using 36.1% or 44.9% of input water, as compared to control, by irrigation at only R5 or R6 stages, respectively. The AGS292 produced 56.1% of seed yield with 35.4% of input water of control, when irrigated at R5 stage. The results of this study have elucidated that the limited irrigation at R5 stage in soybean can be minimized yield loss with such small quantity of water under the environment of long-term drought stress and the expected shortage of agricultural water in the future.

• Journal of Animal Science and Technology
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• 제47권2호
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• pp.293-304
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• 2005

This experiment was carried out to investigate effects of honeybee venom treatment on the body weight gain, feed conversion and growth rate' in pigs. One hundred twenty nine piglets(LY) from 12 sows were allocated into two groups; honeybee venom-treated group (66 piglets from 6 sows) and non-treated control group (63 piglets from 6 sows). Natural honeybee venom was administrated at 0, 3, 14, 30, and 74 days after birth. The acupoints were Hai-men(ST-25), Du-kou(CV-8) and liao-chao(GV-I) points at 0 day, the regions of castration and tail ampution at 3 days, liao-chao(GV-1) and Bai-hui(GV-20) points at 14(weaning), 30(move into piglet stall) and 74(move into grower stall) days after birth. Control group was injected 1 ml of saline to the same site. Average body weight at 150 days after birth was 98.44 kg in bee venom treated group and 86.24 kg in control group, respectively. Average body weight of treated group was significantly increased by 14.15%(P < 0.0001). Average daily gain of bee venom treated group and control group were 649 g and 569 g, respectively, increased by 14.06%(P< 0.0001). Feed conversion of the treated group was 2.21 and control group was 2.49, increased by 11.25% in control group(P < 0.001). Survival rate at weaning was 95.5 % in treated group and 92.0% in control group, at growing(74 days after birth) was 92.4% in treated group and 85.7% in control group and survival rate at finishing(l50 days after birth) was 89.5 % and 79.4 %, respectively. Collecting together, the results in this study showed that growth performance and feed conversion were increased by treatment of natural honeybee venom to pigs. These results suggested that the treatment of bee venom could be used effectively for the increase productivity of livestock industry.

• 한국물환경학회지
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• 제35권3호
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• pp.234-247
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• 2019

In a deep lake and reservoir, thermal stratification is of great importance for characteristics of hydrodynamic mixing of the waterbody, and thereby influencesvertical distribution of dissolved oxygen, substances, nutrients, and the phytoplankton community. The purpose of this study, was to project the effect of a future climate change scenario on water temperature, stratification strength, and thermal stability in the Soyanggang Reservoir in the Han River basin of South Korea, using a suite of mathematical models; SWAT, HEC-ResSim, and CE-QUAL-W2(W2). W2 was calibrated with historical data observed 2005-2015. Using climate data generated by HadGEM2-AO with the RCP 4.5 scenario, SWAT predicted daily reservoir inflow 2016-2070, and HEC-ResSim simulated changes in reservoir discharge and water level, based on inflow and reservoir operation rules. Then, W2 was applied, to predict long-term continuous changes of water temperature, in the reservoir. As a result, the upper layer (5 m below water surface) and lower layer (5 m above bottom) water temperatures, were projected to rise $0.0191^{\circ}C/year$(p<0.05) and $0.008^{\circ}C/year$(p<0.05), respectively, in response to projected atmospheric temperature rise rate of $0.0279^{\circ}C/year$(p<0.05). Additionally, with increase of future temperature, stratification strength of the reservoir is projected to be stronger, and the number of the days when temperature difference of the upper layer and the lower layer becomes greater than $5^{\circ}C$, also increase. Increase of water temperature on the surface of the reservoir, affected seasonal growth rate of the algae community. In particular, the growth rate of cyanobacteria increased in spring, and early summer.

• Fisheries and Aquatic Sciences
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• 제14권2호
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• pp.105-110
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• 2011

This study determined the effects of the dietary moisture level and feeding rate on the growth and gastric evacuation of young olive flounder. Four experimental diets with different moisture levels (9%, 21%, 30%, and 40%) were prepared through the addition of water to the commercial extruded pellet. Three replicate groups of fish (initial weight: $106{\pm}1.4\;g$) were fed diets containing 9%, 21%, 30%, and 40% moisture to satiation or a moisture level of 9% and 30% at a restricted feeding rate (95% of satiation) for 15 weeks. The mean water temperature was $22{\pm}1.6^{\circ}C$ during the feeding trial. Gastric evacuation rates were determined post-feeding. The dietary moisture levels did not significantly affect weight gain, but the weight of the fish receiving 9% and 30% moisture diets to 95% satiation were significantly lower than those of the fish fed 9-40% moisture diets to 100% satiation (P<0.05). The feed efficiency, protein efficiency ratio, viscerosomatic index, and survival were not significantly affected by the dietary moisture levels and feeding rates. The daily feed intake of the fish fed to 100% satiation did not significantly differ among the treatment groups. The stomach contents that peaked within 3 h of feeding gradually decreased, and the stomachs of fish were completely evacuated within 18 h. The contents of the intestine peaked at 3-12 h post-feeding, and then declined with the intestine being mostly evacuated at 30 h. The moisture of the stomach contents reached approximately 70% within 3 h post-feeding and gradually increased to approximately 75% within 12 h. No considerable differences were observed in the gastric evacuation and moisture levels of the stomach contents in the fish fed the different diets. The results of this study suggest that the gastric evacuation of olive flounder was not affected by the dietary moisture level and that the addition of water into the diet displayed no beneficial effects on the growth of young olive flounder.

• Asian-Australasian Journal of Animal Sciences
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• 제29권3호
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• pp.436-443
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• 2016

Exposure to cold may affect growth performance in accordance with the metabolic and immunological activities of animals. We evaluated whether ambient temperature affects growth performance, blood metabolites, and immune cell populations in Korean cattle. Eighteen Korean cattle steers with a mean age of 10 months and a mean weight of 277 kg were used. All steers were fed a growing stage-concentrate diet at a rate of 1.5% of body weight and Timothy hay ad libitum for 8 weeks. Experimental period 1 (P1) was for four weeks from March 7 to April 3 and period 2 (P2) was four weeks from April 4 to May 1. Mean ($8.7^{\circ}C$) and minimum ($1.0^{\circ}C$) indoor ambient temperatures during P1 were lower (p<0.001) than those ($13.0^{\circ}C$ and $6.2^{\circ}C$, respectively) during P2. Daily dry matter feed intake in both the concentrate diet and forage groups was higher (p<0.001) during P2 than P1. Average daily weight gain was higher (p<0.001) during P2 (1.38 kg/d) than P1 (1.13 kg/d). Feed efficiency during P2 was higher (p = 0.015) than P1. Blood was collected three times; on March 7, April 4, and May 2. Nonesterified fatty acids (NEFA) were higher on March 7 than April 4 and May 2. Blood cortisol, glucose, and triglyceride concentrations did not differ among months. Blood CD4+, CD8+, and CD4+CD25+ T cell percentages were higher, while CD8+CD25+ T cell percentage was lower, during the colder month of March than during May, suggesting that ambient temperature affects blood T cell populations. In conclusion, colder ambient temperature decreased growth and feed efficiency in Korean cattle steers. The higher circulating NEFA concentrations observed in March compared to April suggest that lipolysis may occur at colder ambient temperatures to generate heat and maintain body temperature, resulting in lower feed efficiency in March.

• Asian-Australasian Journal of Animal Sciences
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• 제22권8호
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• pp.1180-1185
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• 2009

Two experiments were carried out to study the effects of dietary energy level on nutrient digestion, nitrogen (N) utilization, growth performance, insulin-like growth factor-I (IGF-I), and insulin-like growth factor binding protein-3 (IGFBP-3) in plasma, liver and longissimus dorsi muscle in growing-finishing pigs. In experiment 1 (Exp 1), 15 castrated male pigs (Duroc${\times}$Landrace${\times}$Large White) (Body weight, BW, 55.6${\pm}$1.8 kg) were divided into three groups and fed rations containing 13.33, 14.87 and 17.35 MJ digestible energy (DE)/kg as treatments I, II and III, respectively, using soybean oil as an energy source. The experiment lasted 8 days and faecal and urinary samples were collected during the last 3 days. The results showed that the digestibility of dry matter (DM), energy and N was increased from treatments I to III (p<0.01). N-retention and N-retention rate were not influenced by dietary DE level (p>0.05). In experiment 2 (Exp 2), 36 female pigs (Duroc${\times}$Landrace${\times}$Large White) (BW 41.5${\pm}$3.8 kg) were divided into three groups. The pigs were fed with the same three rations used in Exp 1 for 60 days. At the end of Exp 2, eight pigs were selected from each group for blood sampling and 4 pigs for slaughter trial. The results indicated that average daily feed intake (ADFI) and N-intake were significantly decreased (p<0.01), and DE intake (p<0.01) and average daily gain (ADG) (p<0.05) were increased. IGF-I and IGFBP-3 in plasma were increased (p<0.05). No significant differences in IGF-I and IGFBP-3 in liver and longissimus dorsi muscle were found between different treatments. It was concluded that higher dietary DE level improved nutrient digestibility, ADG and feed/gain ratio when soybean oil was used as an energy source in the ration of growing-finishing pigs. No significant differences were found in Nretention and IGF-I and IGFBP-3 in liver and longissimus dorsi muscle between different treatments.

• Asian-Australasian Journal of Animal Sciences
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• 제22권3호
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• pp.365-370
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• 2009

An experiment was conducted to evaluate the effect of different levels of supplemental selenomethionine (Se-Met) on growth performance and serum antioxidant status in Taihang Black goats. Fifty 16-week-old goats with an average body weight of 12.5${\pm}$0.5 kg were randomly assigned to five treatments fed a basal diet (0.049 mg Se/kg DM) supplemented with 0 (control), 0.10, 0.30, 0.50 and 1.00 mg of Se/kg DM (form Se-Met) for 80 days. Average daily gain and feed efficiency were higher (p<0.05) in the groups supplemented with 0.30 to 0.50 mg Se/kg DM compared with the control group. However, Se-Met supplementation had no influence on average daily feed intake (p>0.05). Se-Met supplementation significantly increased (p<0.01) the activity of glutathione peroxidase enzymes (GSH-Px) and superoxide dismutase (SOD) in serum. The group supplemented with 0.50 mg Se/kg DM had the highest activity of GSH-Px compared with other groups (p<0.05). Serum SOD activity was higher (p<0.05) in goats supplemented with both 0.30 and 0.50 mg Se/kg DM than in control goats and goats supplemented with 1.00 mg Se/kg DM. Serum glutathione-S-transferase (GST) activity and malondialdehyde (MDA) concentration were significantly decreased (p<0.05) in goats supplemented with 0.30, 0.50 and 1.00 mg Se/kg DM compared with control values. These results indicated that Se-Met supplementation markedly improved the antioxidant status in goats. Blood Se concentration increased linearly (p<0.001) and quadratically (p<0.001) as the level of supplemental Se-Met increased. The concentration of Se in the control diet (0.049 mg Se/kg DM) did not satisfy the Se requirement in goats as indicated by reduced growth rate, feed efficiency, activities of GSH-Px and SOD in serum, and blood Se concentrations. In conclusion, it is recommended that 0.30 to 0.50 mg of Se/kg DM from Se-Met (total diet Se of 0.349 to 0.549 mg/kg DM) be supplied in the diet of Taihang Black goats to enhance growth performance and improve antioxidant status.

• 한국패류학회지
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• 제19권2호
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• pp.143-152
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• 2003

우리나라 남해안의 남면, 회진 및 돌산의 3개 해역에서 해만가리비의 사육기간 중 수온은 10.4-25.5$^{\circ}C$로 해역별 수온차이는 크지 않았으며, 염분은 25.00-31.17 psu, 용존산소는 최저 6.13 mg/l 이상으로 해만가리비 성장에 적합한 범위였다 . Chlorophyll-a는 1.69-7.40 $^{\mu}$g/l 로 낮은 농도를 보인 시기도 있었다. 6-8월 해만가리비 성장기에 phytoplankton 우점종은 성장이 좋았던 남면에서는 편모조류인 Ceratium sp.가 35.2%, 회진에서는 Ceratium sp.가 25.5%출현하였으나, 성장이 낮았던 돌산에서는 규조류인 Chaetoceros sp.가 40.4%로 우점하였다. 플랑크톤의 밀도는 대체적으로 8-9월에 높았고, 10월에 낮았다. 해만가리비의 치패를 대상으로 185 일간의 사육한 결과 , 각고는 남면 0.19 mm/day, 회진 0.18 mm/day, 돌산 0.16 mm/day였고, 전중량은 남면 0.16 g/day, 회진 0.16 g/day, 돌산 0.13 g/day 였다. 각고의 일간성장률은 남면이 0.606%, 회진 0.581%, 돌산 0.549%였고, 전중량의 일간성장률은 남면에서는 1.972%, 회진에서는 1.857%, 돌산에서는 1.746%였다. von Bertalanffy 성장모델에 의해 얻어진 각고의 최대 예상값은 각각 52.62 mm (남면), 51.74 mm (회진), 48.91 mm (돌산)였다. 생존율은 남면이 87.0%로 가장 높았으나, 회진 및 돌산은 11월 이후 급감하였다.