• Journal of Marine Bioscience and Biotechnology
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• v.1 no.2
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• pp.91-97
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• 2006

For efficient removal of nitrogenous compounds produced in recirculating aquaculture system, the N removal characteristics of immobilized mixed microorganisms were investigated at various mixing ratios of photosynthetic bacteria (PSB) immobilized in PVA beads or CTA cubes and ammonium utilizing bacteria (AUB) immobilized in PVA beads. On the optimal medium of AUB, the maxium gas production rate was obtained at the mixing ratio of 10:40 (PSB:AUB), and the gas production rate increased as the portion of AUB beads in the mixed beads increased. When the mixing ratios of PSB:AUB beads were 50:0, 40:10, 25:25 and 10:40, the final pHs were measured to be 6.29, 6.01, 5.69 and 5.13, respectively. On the optimal medium of PSB, however, the volume and the rate of gas production decreased remarkably as the portion of AUB beads in the mixed beads increased. The final pH was measured to be approximately 6.5, regardless of the mixing ratio. In the reactions by the mixed culture of PSB cubes and AUB beads, all results showed the same tendency of those by the mixed culture of PSB and AUB beads, but the volume and the rate of gas production decreased remarkably, even with 0.2ml of gas production in control. From all the results, the use of mixed PSB and AUB beads at the ratio of 10:40 seems to be efficient to remove nitrogenous compounds in wastewater from recirculating aquaculture system.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.4
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• pp.502-511
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• 2005

The effects of different levels of crude protein (CP) and cottonseed meal replacing for soybean meal in cassava chips and rice straw-based diets for mid-lactating cows (100-150 day in milk [DIM]), were studied using 32 multiparous Holstein Fresian crossbred dairy cows. Diets containing 10.5, 12.5, 13.7, 14.4% CP of the rations and 0, 12.1, 14.9, 17.8% cottonseed meal were fed to cows for 60 days. Thirty two cows were randomly divided into four dietary treatments using a Randomized complete block design. Four dietary treatments were offered in the form of total mixed ration (TMR) with concentrate to roughage (chopped rice straw) at 60:40 and offered ad libitum. Dry matter (DM) and neutral detergent fiber (NDF) intakes tended to linearly increase with increasing dietary CP levels. Intakes and digestibility of crude protein increased linearly with increasing dietary CP level (p<0.01). Crude protein digestibility of the 10.5% CP diet was lower (p<0.05) than that in diets with higher levels of CP, while there were no significant differences among the other three levels of CP (12.5, 13.7 and 14.4%). Daily milk yield tended to increase with increased CP from 10.5 to 14.4%. Income over feed in terms of US$/kg of milk increased with increased CP from 10.5 to 13.7% and decreased when the CP level was higher than 13.7% (quadratic effect p<0.09). Milk composition was not significantly affected by increasing level of CP, however there were relatively high contents of protein and fat among treatments. The proportion of milk-urea N (MUN), ammonia-N ($NH_3$-N) and bloodurea N (BUN) were closely correlated and increased linearly with increasing CP levels (p<0.01). Balanced diet was found in diet containing 12.5 and 13.7% CP of the rations when BUN and MUN were used as indicators of the protein to energy ratio in the diet. Conclusions can be made that increasing dietary CP levels from 10.5 to 13.7% using cottonseed meal as the main source to completely replace soybean meal was beneficial to cows consuming rice straw and cassava chips based-diets. Increasing the CP level above 13.7% of total ration did not additionally improve milk yield and composition or net income.

• Korean Journal of Microbiology
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• v.33 no.4
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• pp.267-273
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• 1997

Various physico-chemical and microbiological parameters of a composting system were compared with respect to their potential use for the monitoring and evaluation of composting processes for cattle manure. The temperature changed within a range of $30-65^{\circ}C$ during the whole composting process, and the period of active composting (>$40^{\circ}C$) persisted for 16 days. The concentrations of total carbon, total nitrogen, and organic matter decreased by 15% during active composting, but significant changes in C/N ratio were not observed. The decrease of temperature in the latter period of active composting caused a decrease of $NH_4^+-N$ and an increase of $NO_3^--N$ in the composting pile. When temperature exceeded $50^{\circ}C$, the population of thermophiles was higher than that of mesophiles by more than 1 or 2 orders of magnitude. Correlation analyses showed that amylase activity correlated positively with the population of mesophiles and reducing sugar content, but negatively with the population of thermophiles. Amylase activity was higher at the beginning of active composting, whereas cellulase, xylanase and ligninase activities which showed close relationship with each other, increased continually during active cornposting, suggesting the distinction of temporal niches between amylose-degrading and lignocellulose-degrading bacteria in the same habitat.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.4
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• pp.291-296
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• 1986

A pot experiment was conducted to find out the effects of water management and application of slaked lime and wollastonite on Pb uptake of rice in a Pb added soil. The soil was adjusted to 0, 150, 300 and 600 ppm of Pb concentration. The slake lime was applied at the equivalent amount of lime requirement with 150kg/10a adding and the wollastonite, 200kg/10a, respectively. The results obtained were as follows. 1. The lead contents in leaf stem and brown rice increased with increasing the soil Pb content and the ratio of Pb/(Ca+Mg) equivalent in soil but they showed no influence on yields. 2. The application of lime and wollastonite reduced Pb content in plant. 3. The lead content in plant was higher in intermittently irrigated treatment than in submersed irrigation. 4. The soil pH was increased in the order of lime, wollastonite and control. 5. $1N-NH_4$ OAC soluble Pb content in soil was higher in the submersed irrigation than in the intermittently irrigated and was higher in wollastonite application treatment than the slaked lime after harvesting.

• Korean Journal of Environmental Agriculture
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• v.38 no.4
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• pp.225-236
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• 2019

BACKGROUND: Hydroponics is one of the methods for evaluating plant production using the inorganic nutrient solutions, which is applied under the artificial light conditions of plant factory system. However, the application of the conventional inorganic nutrients for hydroponics caused several environmental problems: waste from culture mediums and high nitrate concentration in plants. Organic nutrients are generally irrigated as a supplementary fertilizer for plant growth promotion under field or greenhouse conditions. Hydroponic culture using organic nutrients derived from the agricultural by-products such as dumped stems, leaves or immature fruits is rarely considered in plant factory system. Effect of organic or conventional inorganic nutrient solutions on the growth and nutrient absorption pattern of green and red leaf lettuces was investigated in this experiment under fluorescent lamps (FL) and mixture Light-Emitting Diodes (LEDs). METHODS AND RESULTS: Single solution of tomatoes (TJ) and kales (K) deriving from agricultural by-products including leaves or stems and its mixed solution (mixture ration 1:1) with conventional inorganic Yamazaki (Y) were supplied for hydroponics under the plant factory system. The Yamazaki solution was considered as a control. 'Jeockchima' and 'Cheongchima' lettuce seedlings (Lactuca sativa L.) were used as plant materials. The seedlings which developed 2~3 true leaves were grown under the light qualities of FL and mixed LED lights of blue plus red plus white of 1:2:1 mixture in energy ratio for 35 days. Light intensity of the light sources was controlled at 180 μmol/㎡/s on the culture bed. The single and mixture nutrient solutions of organic and/or inorganic components which controlled at 1.5 dS/m EC and 5.8 pH were regularly irrigated by the deep flow technique (DFT) system on the culture gutters. Number of unfolded leaves of the seedlings grown under the single or mixed nutrient solutions were significantly increased compared to the conventional Y treatment. Leaf extension of 'Jeockchima' under the mixture LED radiation condition was not affected by Y and YK or YTJ mixture treatments. SPAD value in 'Jeockchima' leaves exposed by FL under the YK mixture medium was approximately 45 % higher than under conventional Y treatment. Otherwise, the maximum SPAD value in the leaves of 'Cheongchima' seedlings was shown in YK treatment under the mixture LED lights. NO₃-N contents in Y treatment treated with inorganic nutrient at the end of the experiment were up to 75% declined rather than increased over 60 % in the K and TJ organic treatment. CONCLUSION: Growth of the seedlings was affected by the mixture treatments of the organic and inorganic solutions, although similar or lower dry weight was recorded than in the inorganic treatment Y under the plant factory system. Treatment Y containing the highest NO₃-N content among the considered nutrients influenced growth increment of the seedlings comparing to the other nutrients. However effect of the higher NO₃-N content in the seedling growth was different according to the light qualities considered in the experiment as shown in leaf expansion, pigmentation or dry weight promotion under the single or mixed nutrients.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.6
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• pp.797-805
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• 2014

The effect of concentrate mixtures with crude protein (CP) levels 10%, 13%, 16%, and 19% and diets with roughage to concentrate ratios 80:20, 60:40, 40:60, and 20:80 (w/w) were determined on dry matter (DM) and organic matter (OM) digestibility, and fermentation metabolites using an in vitro fermentation technique. In vitro fermented attributes were measured after 4, 24, and 48 h of incubation respectively. The digestibility of DM and OM, and total volatile fatty acid (VFA) increased whereas pH decreased with the increased amount of concentrate in the diet (p<0.001), however CP levels of concentrate did not have any influence on these attributes. Gas production reduced with increased CP levels, while it increased with increasing concentrate levels. Ammonia nitrogen ($NH_3$-N) concentration and microbial CP production increased significantly (p<0.05) by increasing CP levels and with increasing concentrate levels in diet as well, however, no significant difference was found between 16% and 19% CP levels. Therefore, 16% CP in concentrate and increasing proportion of concentrate up to 80% in diet all had improved digestibility of DM and organic matter, and higher microbial protein production, with improved fermentation characteristics.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.7
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• pp.1004-1009
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• 2006

Four male crossbred native beef cattle (average body weight of 427.7 kg) were randomly allocated to four types of cassoy-urea pellet as a source of protein in concentrate according to a $4{\times}4$ Latin square design to determine effect of diets on ruminal fermentation and nutrient digestibility. The four types of cassoy-urea pellets contained cassava hay, soybean meal, urea and binding agent at 79.2:19.8:0:1 (27.9% CP dry matter), 78.4:19.6:1:1 (30.4% CP), 77.6:19.4:2:1 (33.0% CP) and 99:0:0:1 (23.8% CP) for dietary treatments; 1, 2, 3 and 4, respectively. All four concentrate mixtures contained similar crude protein levels (11% CP) and were fed to animals in two equal parts (0.5% of body weight per day) while urea-treated rice straw (5% urea) was given ad libitum. The experiment revealed that dietary concentrate treatments had no effect on dry matter intake while digestibilities of neutral-detergent fiber and crude protein were higher (p<0.05) in cattle fed dietary treatments 1, 2 and 3 than in cattle fed dietary treatment 4. Ruminal ammonia-nitrogen ($NH_3$-N), was higher and acetic acid concentration (C2) and ratio of C2 to propionic acid (C3) were lower (p<0.05) in cattle fed dietary treatments 1, 2 and 3 than in those on treatment 4. It is concluded that use of cassoy-urea pellet as a protein source in concentrates for cattle resulted in improvement of digestibility, ruminal fermentation and rumen ecology. Further research using cassoy-urea pellet in feeding trials with milking cows and fattening beef should be undertaken.

• Korean Journal of Microbiology
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• v.38 no.1
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• pp.31-37
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• 2002

For elucidating the correlation between the eubacterial community structure and environmental parameters in Nammae Reservoir located in Kyungsan, Kyungbuk, the bacterial community structure and their structure affecting environmental parameters were analyzed using Fluorescent In Situ Hybridization (FISH) monthly over year. $\alpha$ . $\beta$ . $\gamma$-subclasses of Proteobacteria and Cytophaga-Flavobacterium (CF) group known as dominant bacterial group in freshwater were detected in 3 stations over year. The ratio of each subclass to total bacteria was determined; $\alpha$.$\beta$ . $\gamma$-subclasses and CF group varied in the range of 4.0~29.2%, 1.7~25.8%, 1.8~12.8%, 4.9~36.3%, respectively and there was no substantial differences between stations. In terms of the correlation between each group specific bacteria and environmental parameters such as temperature, SS, pH, DOC, NH$_4$-N, NO$_3$-N, PO$_4$-P, standing crops of algae, the results were as follows: 1) total bacterial numbers correlated positively with temperature, SS and DOC, 2) Eubacteria positively with DOC and Chl-$\alpha$, 3)${\gamma}$-subclass positively with DOC, and 4) CF group positively with standing crops of chlorophyceae, 5) whereas $\beta$-subclass bacteria correlated negatively with standing crop of cyanobacteria and that of total algae.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.10
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• pp.1643-1653
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• 2018

Objective: This study investigated the effect of dietary crude protein (CP) supplementation on nutrient intake, nitrogen (N) utilisation, blood metabolites, ruminal fermentation and growth performance of young Holstein bulls. Methods: Twenty-one young bulls weighing $277{\pm}11.2kg$ were equally divided into three groups and were offered diets formulated with low CP (LCP; 10.21% CP and 4.22% rumen degradable protein [RDP]), medium CP (MCP; 12.35% CP and 5.17% RDP) and high CP (HCP; 14.24% CP and 6.03% RDP). Yellow corn silage was used as a unique forage source and was mixed with concentrate. This mixed feed was given ad libitum to the young bulls included in the study. Results: Results showed that CP intake, blood urea nitrogen, N intake, total N excretion and N balance increased linearly with an increase in dietary CP level (p<0.05). However, no significant difference was observed in nutrient digestibility among the bulls receiving the different diets. Ruminal pH (p<0.05) and ammonia nitrogen ($NH_3-N$) concentration (p<0.01) were significantly higher in the bulls receiving the MCP and HCP diets than in those receiving the LCP diet. The bulls receiving the HCP diet showed significantly higher ruminal bacterial protein level, propionate, acetate and total volatile fatty acid (TVFA) concentrations than bulls receiving the LCP diet (p<0.05). Moreover, dietary CP level exerted a significant positive effect on the final body weight, average daily gain and gain-to-feed ratio of the bulls (p<0.05). Conclusion: High dietary CP level is optimal for achieving maximum growth and high profitability without exerting a negative effect on the physiology of growing Holstein bulls.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.1
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• pp.36-45
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• 2014

The objective of this study was to determine the effects of protein sources and roughage (R) to concentrate (C) ratio on in vitro fermentation parameters using a gas production technique. The experimental design was a $2{\times}5$ factorial arrangement in a completely randomized design (CRD). Factor A was 2 levels of protein sources yeast fermented cassava chip protein (YEFECAP) and soybean meal (SBM) and factor B was 5 levels of roughage to concentrate (R:C) ratio at 80:20, 60:40, 40:60, 20:80, and 0:100, respectively. Rice straw was used as a roughage source. It was found that gas production from the insoluble fraction (b) of YEFECAP supplemented group was significantly higher (p<0.05) than those in SBM supplemented group. Moreover, the intercept value (a), gas production from the insoluble fraction (b), gas production rate constants for the insoluble fraction (c), potential extent of gas production (a+b) and cumulative gas production at 96 h were influenced (p<0.01) by R:C ratio. In addition, protein source had no effect (p>0.05) on ether in vitro digestibility of dry matter (IVDMD) and organic (IVOMD) while R:C ratio affected the IVDMD and IVOMD (p<0.01). Moreover, YEFECAP supplanted group showed a significantly increased (p<0.05) total VFA and $C_3$ while $C_2$, $C_2:C_3$ and $CH_4$ production were decreased when compared with SBM supplemented group. In addition, a decreasing R:C ratio had a significant effect (p<0.05) on increasing total VFA, $C_3$ and $NH_3$-N, but decreasing the $C_2$, $C_2:C_3$ and CH4 production (p<0.01). Furthermore, total bacteria, Fibrobacter succinogenes, Ruminococcus flavefaciens and Ruminococcus albus populations in YEFECAP supplemented group were significantly higher (p<0.05) than those in the SBM supplemented group while fungal zoospores, methanogens and protozoal population remained unchanged (p>0.05) as compared between the two sources of protein. Moreover, fungal zoospores and total bacteria population were significantly increased (p<0.01) while, F. succinogenes, R. flavefaciens, R. albus, methanogens and protozoal population were decreased (p<0.01) with decreasing R:C ratio. In conclusion, YEFECAP has a potential for use as a protein source for improving rumen fermentation efficiency in ruminants.