• Asian-Australasian Journal of Animal Sciences
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• 제16권3호
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• pp.394-402
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• 2003

Individual and combined supplementation of phosphorus-adequate, wheat-based broiler diets with exogenous phytase and xylanase was evaluated in three experiments. The effects of the enzyme combination in lysine-eficient diets containing wheat and sorghum were more pronounced than those of the individual feed enzymes. The inclusion of phytase plus xylanase improved (p<0.05) weight gains (7.3%) and feed efficiency (7.0%) of broilers (7-28 days post-hatch) and apparent metabolisable energy (AME) by 0.76 MJ/kg DM. Phytase plus xylanase increased (p<0.05) the overall, apparent ileal digestibility of amino acids by 4.5% (0.781 to 0.816); this was greater than the responses to either phytase (3.6%; 0.781 to 0.809) or xylanase (0.7%; 0.781 to 0.784). Absolute increases in amino acid digestibility with the combination exceeded the sum of the individual increases generated by phytase and xylanase for alanine, aspartic acid, glutamic acid, glycine, histidine, isoleucine, phenylalanine, threonine, tyrosine and valine. These synergistic responses may have resulted from phytase and xylanase having complementary modes of action for enhancing amino acid digestibilities and/or facilitating substrate access. The two remaining experiments were almost identical except wheat used in Experiment 2 had a higher phytate concentration and a lower estimated AME content than wheat used in Experiment 3. Individually, phytase and xylanase were generally more effective in Experiment 2, which probably reflects the higher dietary substrate levels present. Phytase plus xylanase increased (p<0.05) gains (15.4%) and feed efficiency (7.0%) of broiler chicks from 4-24 days post-hatch in Experiment 2; whereas, in Experiment 3, the combination increased (p<0.05) growth to a lesser extent (5.6%) and had no effect on feed efficiency. This difference in performance responses appeared to be 'rotein driven'as the combination increased (p<0.05) nitrogen retention in Experiment 2 but not in Experiment 3; whereas phytase plus xylanase significantly increased AME in both experiments. In Experiments 2 and 3 the combined inclusion levels of phytase and xylanase were lower that the individual additions, which demonstrates the benefits of simultaneously including phytase and xylanase in wheat-based poultry diets.

• Asian-Australasian Journal of Animal Sciences
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• 제27권12호
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• pp.1744-1748
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• 2014

A dose-response experiment with seven supplemental pyridoxine levels (0, 0.66, 1.32, 1.98, 2.64, 3.30, and 3.96 mg/kg) was conducted to investigate the effects of pyridoxine on growth performance and plasma aminotransferases and homocysteine of White Pekin ducks and to estimate pyridoxine requirement for these birds. A total of 336 one-day-old male White Pekin ducks were divided to 7 experimental treatments and each treatment contained 8 replicate pens with 6 birds per pen. Ducks were reared in raised wire-floor pens from hatch to 28 d of age. At 28 d of age, the weight gain, feed intake, feed/gain, and the aspartate aminotransferase, alanine aminotransferase, and homocysteine in plasma of ducks from each pen were all measured. In our study, the pyridoxine deficiency of ducks was characterized by growth depression, decreasing plasma aspartate aminotransferase activity and increasing plasma homocysteine. The ducks fed vitamin $B_6$-deficient basal diets had the worst weight gain and feed/gain among all birds and this growth depression was alleviated (p<0.05) when pyridoxine was supplemented to basal diets. On the other hand, plasma aspartate aminotransferase and homocysteine may be the sensitive indicators for vitamin $B_6$ status of ducks. The ducks fed basal diets had much lower aspartate aminotransferase activity and higher homocysteine level in plasma compared with other birds fed pyridoxine-supplemented diets (p<0.05). According to quadratic regression, the supplemental pyridoxine requirements of Pekin ducks from hatch to 28 days of age was 2.44 mg/kg for feed/gain and 2.08 mg/kg for plasma aspartate aminotransferase and the corresponding total requirements of this vitamin for these two criteria were 4.37 and 4.01 mg/kg when the pyridoxine concentration of basal diets was included, respectively. All data suggested that pyridoxine deficiency could cause growth retardation in ducks and the deficiency of this vitamin could be indicated by decreasing plasma aspartate aminotransferase activity and increasing plasma homocysteine.

• 한국수산과학회지
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• 제4권2호
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• pp.55-60
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• 1971

Palaemon modestus 유생을 실험실 수조 내에서 사육한 결과는 아래와 같다. 1. 포란 개체의 산란 소요 시간은 실험실 수조내에서 8시간 이내였다($20^{\circ}C\~20.9^{\circ}C$). 2. 먹이를 주지 않았을 때 6일째부터 사망하기 시작하였다. 3. 유생의 섭이는 3일째부터 활발하므로 사육시 투이시기는 부화 3일째부터가 적당하겠다. 4. 수중 먹이량의 밀도와 식이 관계는 Artemia Salina의 nauplii $2\~6$마리/ml 내에서는 큰 차이가 없었다. 5. 유생 사육일(X)과 먹이량(Y)과의 회귀 관계는 $Y=6.49824X^{1.8384}$이었다. 6. 유생의 갑장 성장은 $Y=1.1608X^{0.10024}$로 표시되었다. 7. 먹이량(X)에 대한 체장(Y)의 회귀 관계는 $Y=2.8114X^{0.12767}$로 표시되었다. 8. 갑장(X)에 대한 체장(Y)의 회귀 관계는 Y= 3.7564X-0.4601로 표시되었다.

• 한국양식학회지
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• 제13권1호
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• pp.69-78
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• 2000

원유중 수용성 획분(WSF)이 양식 대상종인 감성돔 (Acanthopagrus schlegeli), 참돔(Pagrus major) 및 넙치 (Paralichthys olicaceus)의 전기자어에 미치는 영향을 파악하였다. 실험구는 0%(대조구), 25%, 50%, 75% 및 100% WSF로 하였고, 이에 따른 자어의 난황 흡수속도, 유영활성, 서장도, 기형률 및 생존율을 조사하였다. 수정란으로부터 부화후 자어까지 지속적으로 WSF에 노출시켰을 때, 전기자어의 난황 흡수 속도는 3어종 모두 대조구에 비해 고농도의 WSF에서 느렸다. 유영빈도와 유영속도는 WSF 농도가 높아질수록 낮아지는 경향이었고, 성장은 대조구에 비해 고농도의WSF에서 느린 것으로 나타났다. 고농도의 WSF(50%, 75% 및 100%) 노출은 대조구에 비해 높은 기형률을 나타내었고, 3어종중 참돔의 자어에서 가장 높았다. 전기자어의 생존율은 3어종 모두에서 WSf 농도가 높을수록 낮았다. 부화후의 자어를 WSF에 노출시켰을 때, 유영활성은 3어종 모두에서 SF 농도가 높아질수록 낮아지는 경향이었다. 기형률은 고농도의WSF (50%, 75% 및 100%)에서 높았으며, 3종중 참돔에서 가장 높았다. WSF 농도가 높아짐에 따라 생존율도 유의하게 낮아졌다.

• 한국응용곤충학회지
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• 제53권3호
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• pp.287-293
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• 2014

팥나방 (Matsumuraeses phaseoli) (나비목: 잎말이나방과)은 한국에서 팥 (Vigna angularis)과 녹두 (Vigna radiata)의 꽃과 꼬투리를 가해하는 주요 해충의 하나인데, 수원지방에서 이 곤충의 발육 특성과 월동태를 추정할 목적으로 야외 ($37^{\circ}$16'N $126^{\circ}$59'E 35ASL) 조건에서 인공사육을 통해 발육과정이 관찰되었다. 갓 부화한 유충 집단들은 약 14일 간격으로 인공사료를 이용하여 1년 이상 야외에서 사육되었는데, 봄에서 고온인 여름철로 감에 따라 발육기간이 짧아지고, 가을철로 감에 따라 다시 길어지는 경향이었다. 유충 혹은 번데기 발육에서 여름철 하면 현상은 발견되지 않았다. 2008년 10월 8일 사육이 시작된 집단은 번데기 상태로 월동하였는데, 6%의 생존율을 보이며 이듬해 4월말 우화하였다. 10월 23일에 사육이 시작된 집단은 노숙유충태로 월동하였는데, 이듬해 4월말 용화하여, 5월 초중순에 2%의 최종 생존율을 보이며 우화하였다. 한편 실내에서 사육되어 5령까지 발육된 유충들을 11월과 2월 사이에 야외로 옮겨 사육하였을 때, 생존하는 개체들은 발견하지 못하였다. 항온조건 ($25^{\circ}C$, 15L:9D)에서 갓 산란된 알을 11월과 12월 중에 야외로 옮겨 유지하였을 때, 월동하여 부화하는 알은 발견되지 않았다. 또 항온조건에서 갓 우화한 성충들을 11월과 12월 중 야외로 옮겨 사육하였을 때, 모두 사망하였다. 이 결과로 팥나방은 한국의 수원지방에서 10월 중 부화한 유충들이 유충과 번데기로 월동할 수 있는 것으로 추정되었다.

• 한국응용곤충학회지
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• 제53권3호
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• pp.311-315
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• 2014

꽃매미는 약충과 성충이 무리지어 식물체 흡즙하거나 그 과정에서 감로를 배출하여 그을음병을 유발시킴으로서 포도 등에 피해를 주는 외래해충이다. 본 연구는 경기도내 주요 포도 재배지에서 꽃매미의 발생특성과 월동기 극저온이 꽃매미 월동난괴의 생존율에 미치는 영향을 분석하기 위해 2010년부터 2013년까지 수행하였다. 경기지역에서 꽃매미 월동난괴는 5월 상순부터 부화하기 시작하여 5월 중순에 가장 높은 약충 밀도를 보이고 있으며 7월 하순부터 출현한 성충은 11월 상순까지 산란하는 특성을 보였다. 동절기 온도가 꽃매미 월동난괴 생존율에 큰 영향을 미쳤으며, 1월 중 극저온 출현일수(x)와 생존율(y) 간 관계를 선형회귀모형으로 분석하였다. 그 결과 예측치와 실측치 간 잔차자승합(residual sum of square) 가장 낮은 모형은 $-11^{\circ}C$를 임계 극저온으로 취급한 y = -1.0486 x + 94.496 ($R^2=0.7067$) 이었다. 본 연구 결과는 월동 중 꽃매미 알의 생존율 예측과 봄철 발생시기 정보를 제공함으로써 꽃매미 관리전략 수립에 유용하게 활용될 수 있을 것으로 판단된다.

• 농업과학연구
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• 제47권3호
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• pp.605-614
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• 2020

This study was conducted to compare the growth performances of three groups of commercial Korean native chickens (KNCs) including two strains of crossbreeds and H3 (Hanhyeop 3) from hatch to twelve weeks of age. (1A, 2A, and H3). A total of 468 one-day-old chicks were allocated in a completely randomized design with 15 replicates per treatment for the crossbreeds and 9 replicates per treatment for H3 (12 birds per cage). Commercial broiler diets (i.e., Week 0 - 5 crude protein [CP] 22.0%, metabolizable energy [ME] 3,025 kcal·kg^-1; week 5 - 8 CP 20.0%, ME 3,100 kcal·kg^-1; week 8 - 12 CP 19.0%, ME 3,150 kcal·kg^-1) were provided according to the Korean Feeding Standard for Poultry on an ad-libitum basis with fresh clean water during the twelve-week period. Body weight gain and shank length (SL) were measured weekly until week 6 and bi-weekly during week 6 to 12. Compared to H3, the two crossbreed groups had a higher body weight (BW) on weeks 3 to 8; however, the bodyweight of H3 on week 10 was significantly higher than the other groups (p < 0.05). Moreover, the average daily feed intake (ADFI) of H3 was higher than that of the two crossbreed groups from hatching to 84 days except for week 3, and H3 showed a lower average daily gain (ADG) on weeks 3 and 10 (p < 0.05). Furthermore, H3 had a higher feed conversion ratio compared to another crossbreed chicken on weeks 1 to 8 and the last week after hatching. Among all the groups, there was no significant difference for shank length during the experimental period.

• Animal Bioscience
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• 제35권1호
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• pp.64-74
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• 2022

Objective: This study was conducted to investigate the effects of dietary multi-strain probiotic (MSP) (Bacillus coagulans Unique IS2 + Bacillus subtillis UBBS14 + Saccharomyces boulardii Unique 28) on performance, gut morphology and expression of nutrient transporter related genes in broiler chickens. Methods: A total of 256 (4×8×8) day-old CARIBRO Vishal commercial broiler chicks of uniform body weight were randomly distributed into four treatments with 8 replicates each and having eight chicks in each replicate. Four dietary treatments were T₁ (negative control-basal diet), T₂ (positive control-antibiotic bacitracin methylene disalicylate at 20 mg/kg diet), T₃ (MSP at 10⁷ colony-forming unit [CFU]/g feed), and T₄ (MSP at 10⁸ CFU/g feed). Results: During 3 to 6 weeks and 0 to 6 weeks, the body weight gain increased significantly (p<0.05) in T₃ and T₄ groups. The feed intake significantly (p<0.05) reduced from T₁ to T₃ during 0 to 3 weeks and the feed conversion ratio also significantly (p<0.05) improved in T₃ and T₄ during 0 to 6 weeks. The humoral and cell mediated immune response and the weight of immune organs were also significantly (p<0.05) improved in T₃ and T₄. However, significant (p<0.05) dietary effects were observed on intestinal histo-morphometry of ileum in T₃ followed by T₄ and T₂. At 14 d post hatch, the relative gene expression of glucose transporter (GLUT5), sodium-dependent glucose transporter (SGLT₁) and peptide transporter (PepT₁) showed a significant (p<0.05) up-regulating pattern in T₂, T₃, and T₄. Whereas, at 21 d post hatch, the gene expression of SGLT₁ and PepT₁ was significantly (p<0.05) downregulated in MSP supplemented treatments T₃ and T₄. Conclusion: The supplementation of MSP at 10⁷ CFU/g diet showed significant effects with improved performance, immune response, gut morphology and expression of nutrient transporter genes. Thus, the MSP could be a suitable alternative to antibiotic growth promoters in chicken diets.

• Journal of Ship and Ocean Technology
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• 제6권4호
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• pp.19-76
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• 2002

The author was appointed by the UK Department of Transport as a fellow Assessor with R. A. Williams during Lord Donaldson's Assessment (1995) of the loss of the OBO ship DERBYSHIRE and in 1996 as a UK Assessor for the planning and surveys of the wreck. He relinquished his appointment in October 1997 and was not thereafter Involved in the review and analysis of data gathered. This paper may be considered to be complementary to the reports of the UK and EC Assessors (Williams and Torchio, 1998a and 1998b) which followed that review and analysis. The paper deals with the history and loss of the ship, Including the concept developed in 1995 of 13 possible loss scenarios in a formal safety Risk Matrix of probability and seriousness. It analyses abnormal wave effects on hatch cover collapse, on ship bending, and on flooding of bow spaces and no. 1 hold. The implosion-explosion mechanics during sinking is outlined to explain the devastation of the wreck. The 1996 and 1997 underwater surveys are outlined as are the findings of fact. Each of the final 14 loss scenarios is analysed in the light of the firm and circumstantial survey evidence, plus many other factors of survey experience, analyses and experiments. The updated Risk Matrix speaks for itself and leads to the prime conclusions and major recommendations.

• 한국양식학회:학술대회논문집
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• 한국양식학회 2003년도 추계학술발표대회 논문요약집
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• pp.28-28
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• 2003

Viable interspecific hybrids between yellowtail flounder (Pleuronectes ferrugineus, Store.) and winter flounder (Pleuronectes americanus, Walbaum) were produced by artificial insemination of yellowtail flounder eggs with winter flounder sperm. However, mean fertilization rate, hatching success and early survival up to 3 weeks post hatch were significantly lower than those of parental pure cross controls (P<0.01). Overall, cytogenetic traits (karyological analysis and estimation of cellular DNA contents using flow cytometry) of hybrid flounder were intermediate between the two parental species. Microsatellite assay was used to distinguish the parental genomes in the hybrids; in most cases, one allele was specific to each of the parents. Morphometrics assessed by body proportions indicated that hybrids generally displayed a morphology intermediate between the maternal and paternal species. Interspecific hybrids exhibited abnormal and retarded gonad development in both sexes based on histological analysis of gonads from adult fish. The sterility of the hybrids presents a significant advantage for their use in aquaculture, as potential escapees would not be capable of reproducing in the wild and contaminating natural stocks.