• 대한토목학회논문집
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• 제31권4B호
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• pp.343-352
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• 2011

본 연구에서는 상류단 경계조건으로 입력되는 본류 유량에 생성과 소멸로 작용하는 지천유입량과 취수량을 포함하여 취수장에서의 취수가 하천흐름 및 수질에 미치는 영향을 살펴보기 위하여 팔당댐 직하류부터 잠실수중보 구간에 RMA-2 모형과 RMA-4 모형을 적용하였다. 수치모의 결과, 잠실수중보 상류에 위치해 있는 5개 취수장에서의 취수는 해당 하천 구간의 유량을 변화시키게 되며, 이는 하천의 수위, 유속 등 수리학적 인자를 변화시키는 것으로 밝혀졌다. 이러한 취수량 반영에 따른 수위 및 유속 변화는 해당 하천 구간의 수질의 변화를 초래하는 것으로 나타났다. 취수장에서 빠져나가는 유량을 포함하여 모의한 경우, 구의, 자양, 풍납취수장 부근에서 취수에 의한 유량 손실로 인하여 유속구조가 심하게 교란되었으며, 취수를 고려하지 않은 경우에 비해 유속은 평균 25% 낮게, 수위는 1.5 cm 높게 나타났다. 취수를 고려하지 않은 경우 전 구간에 걸쳐 농도분포가 평행하게 나타났으나, 취수의 영향을 고려한 경우 구의, 암사 및 자양 취수장 부근에서의 농도분포가 크게 변화함을 확인할 수 있었다. 또한 취수를 고려한 경우 취수에 의한 유랑소멸로 하류구간에서 취수를 고려하지 않은 경우에 비해 BOD 농도가 높게 나타났다. 따라서 자연하천의 동수역학적 흐름 및 오염물질 혼합거동을 보다 정확히 해석하기 위해서는 지천 합류량 뿐만 아니라 취수장으로부터 유출되어 빠져나가는 취수량을 동시에 고려해야 하는 것으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• 제13권2호
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• pp.188-191
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• 2000

Appetite stimulant ether-soluble neutral extract of a high-grain compound feed was separated into four fractions with an open column of silica gel chromatograph using four carrier solutions containing n-pentane and diethyl ether as 100:0 (Fraction A), 90:10 (Fraction B), 75:25 (Fraction C) and 0:100 (Fraction D). The stimulative effects of the fractions were examined by comparing the intake of hay (with or without the fractions) in two-choice test bioassays with cattle. The Fractions A, B and C of the neutral extract stimulated (p<0.05) hay consumption in cattle, whereas Fraction D had no effect on selective feeding when compared with the control fraction. Furthermore, Fractions A, B and C had higher (p<0.05) feeding stimulative indices (FSI) than that of the Fraction D. The results suggest that chemical stimulants to increase palatability of hay are present in the neutral Fractions A, B and C of high-grain concentrate.

• Asian-Australasian Journal of Animal Sciences
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• 제6권2호
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• pp.305-311
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• 1993

A total of thirty male Holstein calves were reared outdoors with simple housings or in warmed pens in three experiments conducted in three consecutive midwinters in Hokkaido. Average outdoor air temperatures during the experiments were between -5.3 and $-6.1^{\circ}C$, and average minimum air temperatures were between -9.7 and $-10.6^{\circ}C$. The age of calves at the start of the experiments were $16{\pm}6$ hours. There was no difference in the liquid feed intake, while the solid concentrate (artificial milk) intake by the calves in the simple housing systems (outdoors, calf hutch and open shed) tended to be higher than those in the warmed pen. No significant differences in the daily gain or the monthly development of wither height were observed among housing systems. There were no serious cases of diarrhea. However, coughing was observed in several of the calves reared in the poorly ventilated warmed pens.

• Asian-Australasian Journal of Animal Sciences
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• 제6권1호
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• pp.61-66
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• 1993

Sixteen Korean native bulls weighing about 211 kg were randomly allotted to investigate the effect of different dietary calcium levels on performance. Feeding period was divided into growing period and fattening period for 180 days. Four calcium levels (0.44, 0.58, 0.72 and 0.86%) were used to each period. Bulls fed the diet containing 0.72% calcium had greater body weight gain and consumed more feed than bulls fed diets containing 0.44, 0.58 and 0.86% calcium and improved in feed efficiency. Bulls fed the diet containing 0.44% calcium were worst in performance. It can be concluded that Korean native bulls in growing and fattening period required no more than 0.72% calcium in diet that contained 0.55% phosphorus, and appeared that when ratio of calcium to phosphorus intake was 1.45, performance of Korean native bulls was most beneficial.

• Asian-Australasian Journal of Animal Sciences
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• 제23권5호
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• pp.563-566
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• 2010

Using an open-circuit system, we compared the methane ($CH_4$) emission from dry cows fed first-cut Timothy silage ($1^{st}$ TY), second-cut Timothy silage ($2^{nd}$ TY), second-cut Italian ryegrass silage ($2^{nd}$ IR), third-cut Italian ryegrass silage ($3^{rd}$ IR), or second-cut red clover silage ($2^{nd}$ RC) as the sole feed. The methane emission ranged from 258.2 L $day^{-1}$ to 396.5 L $day^{-1}$. The methane emission from dry cows fed red clover silage was relatively lower than that from dry cows fed grass silage. However, the methane emission per unit digestible neutral detergent fiber (NDF) intake (dNDFI) did not differ significantly between the experimental silages. The methane emission was significantly correlated with the NDF intake and digestibility. Methane emission had a significant correlation with the quadratic function of dNDFI. The differences in the daily volume of methane emission from cows fed different forages can be explained by dNDFI.

• Asian-Australasian Journal of Animal Sciences
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• 제16권4호
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• pp.534-540
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• 2003

This study was conducted to investigate the effect of supplementation of galacto-oligosaccharides (GOS) on methane emission, nutrient digestibility, energy utilization and blood metabolites by Holstein cows fed silages. In two sequential digestion and respiratory trials, two non-lactating Holstein cows were arranged to a balanced incomplete block design. Experimental diets consisted of two silage types; orchardgrass (Dactylis glomerata L.) based silage (OS), mixed silage (orchardgrass based silage and alfalfa (Medicago sativa L.) silage) (MS), while two GOS levels were without supplementation (0) and 2% of dry matter intake supplementation (2). Four combination diets were OS-0, OS-2, MS-0 and MS-2. Significant effects of silage types and GOS supplementation levels were not observed for DM and OM intake. Whereas the digestibility of OM, NDF and ADF was significantly (p<0.05) higher in cows fed OS with and without GOS compared cows fed MS diets. As percentage of GE intake, fecal energy loss for OS diets was significantly (p<0.05) declined than for MS diets. In contrast, cows fed MS diets had lower (p<0.05) urine energy loss as a proportion of GE intake compared to OS diets. Energy loss as CH4 and heat production was numerically increased when cows fed both OS and MS with GOS supplementation. Compared to OS, CH4 emission in cows fed MS was numerically decreased by 10.8 %. Methane conversion ratio (energy loss as CH4 per unit of GE intake) for OS-0, OS-2, MS-0 and MS-2 were 7.1, 7.2, 6.8 and 7.0, respectively. Plasma of glucose and urea-N concentration were significantly (p<0.05) elevated from 1 h to 6 h after feeding, otherwise total protein in plasma was declined (p<0.01) at 6 after feeding.

• Asian-Australasian Journal of Animal Sciences
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• 제30권2호
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• pp.187-191
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• 2017

Objective: An experiment was conducted to examine the effect of dietary supplementation of dried and ground foliage of black gram (Vigna mungo L.) on feed intake and utilization, and production performance of crossbred lactating cows. Methods: Eighteen lactating crossbred (Bos taurus${\times}$Bos indicus) cows (body weight $330.93{\pm}10.82kg$) at their second and mid lactation (milk yield $6.77{\pm}0.54kg/d$) were randomly divided into three groups of six each in a completely randomized block design. Three supplements were formulated by quantitatively replacing 0, 50, and 100 per cent of dietary wheat bran of concentrate mixture with dried and ground foliage of black gram. The designated supplement was fed to each group with basal diet of rice straw (ad libitum) to meet the requirements for maintenance and milk production. Daily feed intake and milk yield was recorded. A digestion trial was conducted to determine the total tract digestibility of various nutrients. Results: The daily feed intake was increased (p<0.05) with the supplementation of black gram foliage. Although the digestibility of dry matter, organic matter, crude protein, and ether extract did not vary (p>0.05), the fibre digestibility was increased (p<0.05), which ultimately improved (p<0.05) the total digestible nutrients content of composite diet. Although, the average milk yield (kg/animal/d) and composition did not differ (p>0.05) among the groups, milk yield was increased by 10 per cent with total replacement of wheat bran in concentrate mixture with of black gram foliage. The economics of milk production calculated as feed cost per kg milk yield (INR 10.61 vs 7.98) was reduced by complete replacement of wheat bran with black gram foliage. Conclusion: Black gram foliage could be used as complete replacement for wheat bran in concentrate mixture of dairy cows in formulating least cost ration for economic milk production in small holders' animal production.

• Asian-Australasian Journal of Animal Sciences
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• 제2권3호
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• pp.331-332
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• 1989

• 한국초지조사료학회지
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• 제13권2호
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• pp.139-144
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• 1993

홀스타인 암소 육성우에 옥수수사일리지와 볏짚을 급여하면서 영양수준을 80, 100 그리고 12%(NRC 요구량 대비)로 급여할때 육성우의 중체량 및 영양소 섭취량을 조사하기 위하여 육성우 30두를 각 처리당 5두씩 완전임의 배치로 공시히여 체중 400kg까지 시험을 수행한 결과는 다음과 같다. 1. 옥수수사일리지 및 볏짚급여시 육성기 최대 일당중체량은 각각 체중 200과 250kg 일때였다. 2. 체중이 증가할수록 DM, CP 및 TDN 요구량은 증가되었으며 체중 250~300kg 일때 이들 영양소 요구량이 가장 높았다. 3. 체중 250~300kg일때 체중(X)과 DM, CP, TDN 섭취량(I)과의 관계는 다음과 같다. DMI = 8.0168X - 0.0209 (r=0.7986$^{**}$) CPI = 101428X - 0.0145 (r=0.5787$^{**}$) TDNI = 6.7620X - 0.3702 (r=0.6877$^{**}$)

• 한국물환경학회지
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• 제29권3호
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• pp.420-427
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• 2013

In this study, the ecological characteristics of Limnoperna fortunei were surveyed as a preceding research to solve the problem such as biofouling or biowaste caused by those organisms in the closed water pipeline. Limnoperna fortunei was collected not in the main reaches of Somjin River but inside and outside of the intake tower which is located in the lower part of Sueo Reservoir. The dense populations were found at the inlet mouth and near part of the pipeline. Their byssuses were formed as a thick and tightly interwind mat. The rusted parts of the pipeline hold relatively more shells than those of the normal parts. Average count of the numbers ranged $12.1{\sim}136.5ind./m^2$ through the sampling stations (A,B and C). The amount of attached shells at each station were A=386, B=258, and C=71, respectively. The relationships of shell height-length and shell length-width were proportional. The majority sizes in each station ranged A=20.01~22.00 mm (33.9%), B=10.01~14.00 mm (51.2%), and C=18.01~20.00 mm (22.5%), 24.01~26.00 mm (21.1%), respectively. Most of the bigger size of shells on C station was found dead. The ecological habitat seemed less suitable for Limnoperna fortunei when they located farther away from the intake tower of reservoir. From now on, it is necessary to consider the continuous monitoring of this organism.