• 멤브레인
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• 제24권3호
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• pp.201-212
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• 2014

본 연구는 국내 최초로 도입된 Y 정수장의 세라믹막 고도정수처리를 위한 최적 운영 인자를 도출하기 위하여 수행되었다. 경제성과 수질조건을 만족하면서도 세라믹막 여과성능을 지속 유지할 수 있는 최적 운영조건을 도출한 결과, Y 정수장의 평상시 수질 조건에서 막역세척으로 인한 배출수 발생량을 최소화시키면서도 막여과성능을 유지할 수 있는 최적 여과지속시간(역세척 주기)은 시설용량($16,000m^3$/일) 기준 시 4.0시간으로 조사되었다. 또한 화학세척(CIP)에 따른 막차압 회복력을 조사한 결과, 구연산을 이용한 산세정을 통하여 철, 망간, 알루미늄 등의 막 파울링을 일으키는 무기오염물질은 제거되지만 막회복률은 낮았다. 반면 차아염소산나트륨을 사용한 알칼리 세정을 통해서는 막 운영 초기 막차압으로 회복되는 것으로 나타났다. 막차압을 발생시키는 파울링 주요 원인물질은 친수성 고분자 유기오염물인 polysaccharides로 조사되었으며, 화학세척(CIP)시 막성능 회복률은 세척약품 온도에 의한 영향이 매우 크며, 온도가 높은수록 막성능 회복률이 향상되는 것으로 조사되었다.

• Animal Bioscience
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• 제34권6호
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• pp.1038-1048
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• 2021

Objective: The study aimed to evaluate the effect of storage time and formic acid (FA) on fermentation characteristics, epiphytic microflora, carbohydrate components and in vitro digestibility of rice straw silage. Methods: Fresh rice straw was ensiled with four levels of FA (0%, 0.2%, 0.4%, and 0.6% of fresh weight) for 3, 6, 9, 15, 30, and 60 d. At each time point, the silos were opened and sampled for chemical and microbial analyses. Meanwhile, the fresh and 60-d ensiled rice straw were further subjected to in vitro analyses. Results: The results showed that 0.2% and 0.6% FA both produced well-preserved silages with low pH value and undetected butyric acid, whereas it was converse for 0.4% FA. The populations of enterobacteria, yeasts, moulds and aerobic bacteria were suppressed by 0.2% and 0.6% FA, resulting in lower dry matter loss, ammonia nitrogen and ethanol content (p<0.05). The increase of FA linearly (p<0.001) decreased neutral detergent fibre and hemicellulose, linearly (p<0.001) increased residual water soluble carbohydrate, glucose, fructose and xylose. The in vitro gas production of rice straw was decreased by ensilage but the initial gas production rate was increased, and further improved by FA application (p<0.05). No obvious difference of FA application on in vitro digestibility of dry matter, neutral detergent fibre, and acid detergent fibre was observed (p>0.05). Conclusion: The 0.2% FA application level promoted lactic acid fermentation while 0.6% FA restricted all microbial fermentation of rice straw silages. Rice straw ensiled with 0.2% FA or 0.6% FA improved its nutrient preservation without affecting digestion, with the 0.6% FA level best.

• 한국작물학회지
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• 제31권4호
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• pp.420-425
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• 1986

Br, 21을 공시하여 급건엽이 발생하는 환경조건을 구명하기 위하여 온습도를 시험 I과 II로 구분하여 시험 I은 주간의 온습도를 달리하고 야간은 휴건하였으며, 시험 II는 황변 이후에 주야간 동일한 온습도를 건조상 내에서 각기 달리 조사하여 처리하였던 바 그 결과를 요약하면 다음과 같다. 1. 급건엽발생은 고온 저습에 의해 과도한 탈수로 발생되었다. 2. 야간은 휴건하고 주간은 습도 75~80%일 때35$^{\circ}C$ 이하에서는 급건엽이 거의 기생되지 않았다. 3. 주야간 온습도가 일정할 경우 3$0^{\circ}C$는 75~80%, 35$^{\circ}C$는 80~85%, 4$0^{\circ}C$는 85~90%로 온도가 상승할수록 습도를 더 높여야 급건엽이 발생되지 않았다. 4. 급건엽발생이 많을 수록 물리성이 불량하였고, 내용성분이 충분히 분해되지 않았다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권3호
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• pp.410-415
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• 2002

Adrenal glucocorticoids, secreted by the stimulus of adrenocorticotropic hormone (ACTH), are catabolic hormones in the pig. The present study was conducted to find whether active immunization against ACTH would suppress cortisol secretion accompanied by an increased growth rate in growing-finishing barrows. ACTH was conjugated to keyhole limpet hemocyanin or human histone using glutaraldehyde or 3-maleimidobenzoic acid N-hydroxysuccinimide, under a 2 (ACTH vs no hapten)${\times}$2 (carrier)${\times}$2 (crosslinker) factorial arrangement of treatments. Cross-bred barrows weighing approximately 25 kg were injected with an ACTHcarrier or carrier only conjugate every 4th wk and slaughtered at approximately 110 kg body weight. Antibodies against ACTH were detected in serum, as determined by $[^{125}I]$ACTH-binding activity, in most animals immunized against the ACTH conjugate, but not in carrier only-injected animals, except for the animals which had received the hapten conjugated to histone via glutaraldehyde. The $[^{125}I]$ACTH-binding activity of serum increased after the second booster injection, but overall ACTH antibody titer was very low. Main effect was not detected not only for the carrier and crosslinker but for the hapten in serum cortisol concentration, ADG, loin muscle area, backfat thickness and longissimus muscle composition including fat and protein. In addition, bound $[^{125}I]$ACTH percentage had no relation to cortisol concentration or to any of the above growth-related variables. Results suggest that ACTH or its conjugates used in the present study were not immunogenically potent enough to affect the glucocorticoid secretion and thus the growth of the immunized pigs.

• Journal of Animal Science and Technology
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• 제58권2호
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• pp.8.1-8.14
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• 2016

In this research data representing 72,946 primiparous cows from 724 herds with 638,063 total test day records calved between 2001 and 2011. These data were analysed to determine the effect of age at first and season of calving on parameters of the Wood lactation curve. Also, genetic trend of the lactation curve parameters in different calving years were evaluated. The results indicate that the highest rate of atypical lactation curve was related to cows that calved in summer (28.05 %). The maximum phenotypic relationship between initial milk yield and total 305-d milk yield was observed in cows calved in spring (0.40). The role of peak yield is more than peak time on 305-d total milk yield in primiparous Holstein. One month increase in age at first calving from 18 to 26 month raised 305-d milk yield by around 138 kg and from 27 to 32 month decreased by 61 kg. The persistency of lactation between 101 and 200 days is higher than that of 201-305 days. Our results indicate that the shape of lactation curve is largely dependent on the season of calving (higher level of milk production in cows which calved in autumn and winter). The heritabilities of parameters of lactation curve and persistency measures were low. The genetic trends for peak time, peak yield and 305-d milk yields were positive and estimated to be 0.019, 0.021 and 8.13 kg/year respectively. So the range from 24 to 26.5 month of calving is the optimum calving time in primiparous Holstein for maximizing 305-d milk yield.

• 한국식품저장유통학회:학술대회논문집
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• 한국식품저장유통학회 2004년도 총회및 심포지움
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• pp.67-72
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• 2004

Quality of fresh-cut tomato slices was compared during cold storage under various modified atmosphere packaging conditions. Chilling injury of slices in containers sealed with Film A was higher than with Film B; these films had oxygen transmission rates of 87.4 and 60.0 ml $h^{-1}\;m^{-2}\;atm^{-1}$ at $5^{\circ}C\;and\;99\%$ RH, respectively. While slices in containers with an initial atmospheric composition of air, $4\%\;CO_2+1\;or\;20\%\;O_2,\;8\%\;CO_2+1\;or\;20\%\;O_2,\;or\;12\%\;CO_2+20\%\;O_2$ showed fungal growth, slices in containers with $12\%\;CO_2+1\%\;O_2$ did not. Low ethylene in containers enhanced chilling injury. Modified atmosphere packaging provided good quality tomato slices with a shelf-life of 2 weeks or more at $5^{\circ}C$. Experiments were conducted to compare changes in quality of slices of red tomato (Lycopersicon esculentum Mill. 'Sunbeam') fruit from plants grown using black polyethylene or hairy vetch mulches under various foliar disease management systems including: no fungicide applications (NF), a disease forecasting model (Tom-Cast), and weekly fungicide applications (WF), during storage at $5^{\circ}C$ under a modified atmosphere. Slices were analyzed for firmness, soluble solids content (SSC), titratable acidity (TA), pH, electrolyte leakage, fungi, yeasts, and chilling injury. With both NF and Tom-Cast fungicide treatments, slices from tomato fruit grown with hairy vetch (Vicia villosa Roth) mulch were firmer than those from tomato fruit grown with black polyethylene mulch after 12 days storage. Ethylene production of slices from fruit grown using hairy vetch mulch under Tom-Cast was about 1.5- and 5-fold higher than that of slices from WF and NF fungicide treatments after 12 days, respectively. The percentage of water-soaked areas (chilling injury) for slices from tomato fruit grown using black polyethylene mulch under NF was over 7-fold that of slices from tomato fruit grown using hairy vetch under Tom-Cast. When stored at $20^{\circ}C$, slices from light-red tomato fruit grown with black polyethylene or hairy vetch mulches both showed a rapid increase in electrolyte leakage beginning 6 hours after slicing. However, slices from tomato fruit grown using the hairy vetch mulch tended to have lower electrolyte leakage than those grown with black polyethylene mulch. These results suggest that tomato fruit from plants grown using hairy vetch mulch may be more suitable for fresh-cut slices than those grown using black polyethylene mulch. Also, use of the disease forecasting model Tom-Cast, which can result in lower fungicide application than is currently used commercially, resulted in high quality fruit for fresh-cut processing. Experiments were conducted to determine if ethylene influences chilling injury, as measured by percentage of slices exhibiting water-soaked areas in fresh-cut tomato slices of 'Mountain Pride' and 'Sunbeam' tomato (Lycopersicon esculentum Mill.). Ethylene concentration in containers without ventilation significantly increased during storage at $5^{\circ}C$, whereas little or no accumulation of ethylene occurred in containers with one or six perforations. Chilling injury was greatest for slices in containers with six perforations, compared to slices in containers with one perforation, and was over 13-fold greater than that of slices in control containers with no perforations. An experiment was also performed to investigate the effectiveness of including an ethylene absorbent pad in containers on subsequent ethylene accumulation and chilling injury. While ethylene in the no-pad controls increased continually during storage of both 'Mountain Pride' and 'Sunbeam' tomatoes at $5^{\circ}C$ under modified atmosphere conditions, no increase in accumulation of ethylene was observed in containers containing ethylene absorbent pads throughout storage. The ethylene absorbent pad treatment resulted in a significantly higher percentage of chilling injury compared with the no-pad control. In studies aimed at inhibiting ethylene production using AVG during storage of slices, the concentration of ethylene in control containers (no AVG) remained at elevated levels throughout storage, compared to containers with slices treated with AVG. Chilling injury in slices treated with AVG was 5-fold greater than that of controls. Further, we tested the effect of ethylene pretreatment of slices on subsequent slice shelf-life and quality. In slices treated with ethylene (0, 0.1, 1, or $10\;{mu}L\;L^{-1}$) immediately after slicing, ethylene production in non-treated controls was greater than that of all other ethylene pre-treatments. However, pretreatment of slices 3 days after slicing resulted in a different pattern of ethylene production during storage. Ihe rate of ethylene production by slices treated with 1 L $L^{-1}$ ethylene 3 days after slicing was greater during storage than any of the other ethylene treatments. With slices pre-treated with ethylene, both immediately and 3 days after slicing, the rate of ethylene production tended to show an negative correlation with chilling injury. Chemical name used: 1-aminoethoxyvinylglycine (AVG).

• Asian-Australasian Journal of Animal Sciences
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• 제29권4호
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• pp.500-508
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• 2016

This study was conducted to investigate the effects of Momordica charantia saponin (MCS) on ruminal fermentation of maize stover and abundance of selected microbial populations in vitro. Five levels of MCS supplements (0, 0.01, 0.06, 0.30, 0.60 mg/mL) were tested. The pH, $NH_3-N$, and volatile fatty acid were measured at 6, 24, 48 h of in vitro mixed incubation fluids, whilst the selected microbial populations were determined at 6 and 24 h. The high dose of MCS increased the initial fractional rate of degradation at t-value = 0 ($FRD_0$) and the fractional rate of gas production (k), but decreased the theoretical maximum of gas production ($V_F$) and the half-life ($t_{0.5}$) compared with the control. The $NH_3-N$ concentration reached the lowest concentration with 0.01 mg MCS/mL at 6 h. The MSC inclusion increased (p<0.001) the molar proportion of butyrate, isovalerate at 24 h and 48 h, and the molar proportion of acetate at 24 h, but then decreased (p<0.05) them at 48 h. The molar proportion of valerate was increased (p<0.05) at 24 h. The acetate to propionate ratio (A/P; linear, p<0.01) was increased at 24 h, but reached the least value at the level of 0.30 mg/mL MCS. The MCS inclusion decreased (p<0.05) the molar proportion of propionate at 24 h and then increased it at 48 h. The concentration of total volatile fatty acid was decreased (p<0.001) at 24 h, but reached the greatest concentration at the level of 0.01 mg/mL and the least concentration at the level of 0.60 mg/mL. The relative abundance of Ruminococcus albus was increased at 6 h and 24 h, and the relative abundance of Fibrobacter succinogenes was the lowest (p<0.05) at 0.60 mg/mL at 6 h and 24 h. The relative abundance of Butyrivibrio fibrisolvens and fungus reached the greatest value (p<0.05) at low doses of MCS inclusion and the least value (p<0.05) at 0.60 mg/mL at 24 h. The present results demonstrates that a high level of MCS quickly inhibits in vitro fermentation of maize stover, while MCS at low doses has the ability to modulate the ruminal fermentation pattern by regulating the number of functional rumen microbes including cellulolytic bacteria and fungi populations, and may have potential as a feed additive applied in the diets of ruminants.

• Asian-Australasian Journal of Animal Sciences
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• 제13권8호
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• pp.1137-1146
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• 2000

This study was carried out to establish an optimum number of phase feeding regimen which enable to reduce nutrients excretion without affecting growth performance and to investigate the effects of different feeding regimens on growth performance, nutrients excretion and carcass characteristics in finishing pigs. A total of 120 finishing pigs (an average initial body weight of 54.3 kg) were assigned to the feeding trial and 12 pigs were assigned to the metabolic trial. Treatments included one phase (54 to 104 kg), two phase (54 to 80 and 80 to 104 kg), three phase (54 to 70, 70 to 90 and 90 to 104 kg) and four phase (54 to 65, 65 to 80, 80 to 95, 95 to 104 kg) feeding regimens. Experimental diets were formulated to contain 16% crude protein for one phase feeding regimen, 16% and 12% crude protein for two phase feeding regimen, 16%, 14% and 12% crude protein for three phase feeding regimen, and 16%, 14.7%, 13.4% and 12% crude protein for four phase feeding regimen, respectively. Although there were no significant differences in any criteria measured during the entire experimental period, pigs reared in three phase feeding regimen grew slightly faster than those reared in other feeding regimens and showed a tendency to increase ADFI during the whole experimental period. The metabolic trial indicated that there were no significant differences in DM (dry matter), CP (crude protein) and P (phosphorus) digestibilities. However, fecal nutrient excretion except P was significantly influenced by feeding regimens. DM excretion of one phase feeding group was significantly higher than that of three phase feeding group and daily fecal N (nitrogen) excretion of one phase feeding group was higher than that of other phase feeding groups (p<0.05). Three and four phase feeding regimens resulted in 12% lower fecal N and DM excretion than one phase feeding regimen. Blood urea concentrations were lower for pigs reared in two, three and four phase feeding regimens than for those reared in one phase feeding regimen (p<0.05). Three phase feeding regimen for the finishing period showed better carcass grade than one phase feeding regimen, though the difference was not significant. The tenth rib fat thickness of pigs fed on four phase feeding regimen was reduced most and there was a trend that backfat thickness decreased as the number of phases increased. Feed cost per kg weight gain was significantly low in four phase feeding group than one phase feeding group (p<0.05). In summary, it seemed that producers generally oversupply the expensive nutrients for the finishing pigs. High nutrient diets do not always guarantee high growth rate of pigs and cause more unwanted nutrient excretion. It rather seems that meeting nutrient requirements for the each growth phase is more important for the reduction of pollutants and economical pork production.

• Journal of Plant Biotechnology
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• 제36권1호
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• pp.7-12
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• 2009

본 실험은 음나무 배발생 세포의 증식 및 체세포배 발달을 위한 액체 현탁 배양조건의 확립을 위해 수행되었다. 배발생 세포의 생장율은 접종 밀도가 증가할수록 감소하였다. 배발생 세포의 증식에 가장 효과적인 접종 밀도는 0.1 g/100 ml 로서 이 농도에서 세포의 생장율이 가장 높았다. 배양기간에 따른 배발생 세포의 생장 패턴 및 세포 주기 (G1, S, G2/M) 분석 결과, 세포의 생장은 배양 5일 후부터 증가가 시작되어 15일 까지 급격히 생장하였으며 그 이후에는 점차 감소하였다. 배양 기간 별 세포 주기 (cell cycle)의 변화가 명확하게 관찰되어 배양 5일째 5기는 초기의 5.5% 에서 11.7%로 두 배정도 증가하였으며, 배양 15일 이후부터는 다시 초기의 세포 주기로 되돌아가면서 안정화되는 것으로 나타났다. 따라서 음나무 배발생 세포의 현탁배양은 15일의 주기로 배양하는 것이 증식에 가장 효과적인 것으로 생각되었다. 한편 배발생 세포에서 체세포배의 유도는 배양초기의 접종 밀도가 중요한 것으로 나타났다. 0.5 g/L 의 낮은 밀도로 접종 시에는 65% 이상의 어뢰형 배가 유도된 반면 접종 밀도가 높아질수록 어뢰형으로의 배발달은 급격히 감소하였다. 초기의 접종 밀도가 증가할수록 특히 어뢰형 배의 발달은 지연되었으나 구형 및 심장형 배의 유도는 초기 접종밀도에 영향을 받지 않았다. 이상의 실험결과로 음나무 액체 배양 시 초기 접종 밀도를 조절함으로써 배발생 캘러스의 증식 및 체세포배를 효과적으로 유도할 수 있었으며 이는 체세포배 생산을 위한 배양 기간의 단축이 가능함을 보여주는 결과이다.

• Asian-Australasian Journal of Animal Sciences
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• 제23권2호
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• pp.205-212
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• 2010

The effects of chromium (Cr), dietary crude protein (CP) level, and potential interactions of these two factors were investigated in term of energy metabolism in lambs. Forty-eight 9-week-old weaned lambs (Dorper${\times}$Small-tail Han sheep, male, mean initial body weight = 22.96 kg${\pm}$2.60 kg) were used in a 2${\times}$3 factorial arrangement of supplemental Cr (0 ${\mu}g$/kg, 400 $\mu{g}$/kg or 800 ${\mu}g$/kg from chromium yeast) and protein levels (low protein: 157 g/d to 171 g/d for each animal, or high protein: 189 g/d to 209 g/d for each animal). Blood samples were collected at the beginning and end of the feeding trial. The lambs were then sacrificed and tissue samples were frozen for further analysis. Chromium at 400 ${\mu}g$/kg decreased fasting insulin level and the ratio of plasma insulin to glucagon, but these differences were not statistically significant; in contrast, chromium at 800 ${\mu}g$/kg increased the ratio significantly (p<0.05). Protein at the high level increased plasma tumor necrosis factor $\alpha$ (TNF-$\alpha$) level (p = 0.060). Liver glycogen content was increased significantly by Cr (p<0.05), which also increased liver glucose-6-phosphatase (G-6-Pase) and adipose hormone-sensitive lipase (HSL) activity. At 400 ${\mu}g$/kg, Cr increased muscle hexokinase (HK) activity. High protein significantly increased G-6-Pase activities in both the liver (p<0.05) and the kidney (p<0.05), but significantly decreased fatty acid synthase (FAS) activity in subcutaneous adipose tissue (p<0.05). For HSL activity in adipose tissue, a Cr${\times}$CP interaction (p<0.05) was observed. Overall, Cr improved energy metabolism, primarily by promoting the glycolytic rate and lipolytic processes, and these regulations were implemented mainly through the modulation by Cr of the insulin signal transduction system. High protein improved gluconeogenesis in both liver and kidney. The interaction of Cr${\times}$CP indicated that 400 $\mu{g}$/kg Cr could reduce energy consumption in situations where energy was being conserved, but could improve energy utilization when metabolic rate was increased.