• Asian-Australasian Journal of Animal Sciences
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• v.3 no.3
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• pp.231-242
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• 1990

A study is reported which investigated the additive nature of digestible energy (DE) from dietary nutrients and to estimate the relative energy values of different energy-yielding nutrients in practical trout diets. A growth study was conducted over 12 weeks with 6 diets. Rainbow trout (Oncorhynchus mykiss) were fed diets once a day ad libitum. Digestible energy values determined and calculated had direct relationship indicating additive nature of such values for feed ingredients. Overall growth performance was best in a diet containing 33% digestible protein (DP) with a DP/DE ratio of 18.6. A reduction in digestible protein level with the same DP/DE rat io led to a significant decrease in growth and feed efficiency. The increase of 7% of lipid with concomitant decrease in protein resulted in the relative gain of 130% in growth and nutrient retention, suggesting that 1 g of lipid is equal to about 1.3 g of proteins in terms of net energetic value. Replacement of 10% of dietary lipid by carbohydrates led to a slight decrease in energy retention efficiency but to a great increase in lipid retention efficiency (130%) showing that dietary carbohydrates led to increased lipogenesis.

• Journal of Korean Society on Water Environment
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• v.16 no.4
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• pp.501-512
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• 2000

This study was carried out to develop the new process for RBC process which is capable of nutrient removal and to obtain its design parameters for Sludge Settling Type Rotating Biological Contactors by comparing RBC with RBC combined with HBR (Hanmee Bio-Reactor). To achieve more than 90% of organic removal efficiency, organic loading rate less than $6.0g\;BOD/m^2/d$ is recommended. Nitrification rate was about 90% at $6.0g\;BOD/m^2/d$. TN removal efficiency of RBC+HBR was higher than those of RBC1 and RBC2. TN removal efficiency at condition of $5.0g\;BOD/m^2/d$ was about 60% in RBC1. When BOD loading rate was $6.0g\;BOD/m^2/d$. TN removal efficiencies in RBC2 and RBC+HBR were about 70%, 80%, respectively. TP removal efficiency was more than about 67% for RBC1, about 63% for RBC2 and about 71 % for RBC+HBR at the same loading rate. From the blank experiment to observe removal efficiency in the first stage, it can be known that COD removal efficiency was about 30% and suspend solids settling rate was about 45%. It was proved that RBC+HBR is much better in sludge dewatering than RBC.

• Journal of Korean Society on Water Environment
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• v.23 no.1
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• pp.19-26
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• 2007

The lab-scale BNR processes fed with Municipal Wastewater Before or After Primary Clarifier (MWBPC or MWAPC) were operated to observe the behavior of particle organic matter in terms of nitrification and denitrification efficiency. As a result of the fractionation of the COD from MWBPC or MWAPC using an aerobic respirometric serum bottle reactor, the total mass of biodegradable organic matter from MWBPC is about 52% greater than the mass from MWAPC. Batch reactors were operated to observe the effect of the Particulate Organic Matter (POM) on substrate utilization for denitrification. Although the consumption of POM for denitrification was observed, the increment of the Specific Denitrification Rate (SDNR) was not great. In terms of the effect of POM on nitrification at different HRTs, activate sludge reactors were operated to determine the optimal HRT when MWBPC and MWAPC were fed relatively. All reactors showed a great organic matter removal efficiency. Reactors fed with MWAPC had obtained the nitrification efficiency above 90% when the HRT of 4 hr, at least, was maintained, while reactors fed with MWBPC had same efficiency when the HRT longer than 5 hr was kept. Three parallel $A^2/O$ systems fed with MWBPC or MWAPC relatively were operated to investigate the effects of POM on BNR processes with varying the HRT of an anoxic reactor. For all systems, the efficiency of organic matter removal and denitrification, respectively, was great and about the same. In case of denitrification efficiency, system with MWAPC had 1.5% lower than system with MWBPC at the same HRT of anoxic reactor of 2 hr, and the increasing the HRT of the anoxic reactor by 1 hr in systems fed with MWBPC resulted in a 3.5% increment. The denitrification rate was similar while the consumption of organic matter in systems fed with MWBPC was higher than system fed with MWBPC. It suggests that POM in MWBPC was not be used significantly as a substrate for denitrification in system with the HRT of 3 hr of an anoxic reactor.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.9
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• pp.1213-1220
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• 2010

This experiment evaluated the effects of dietary lysine restriction and energy density on growth performance, nutrient digestibility and meat quality of finishing pigs. A $2{\times}2$ factorial arrangement of treatments was utilized in a randomized complete block (RCB) design, and factor 1 was lysine restriction and factor 2 was energy density. The control diet was formulated to contain 3.265 Mcal of ME/kg, 0.75% lysine in the early-finishing phase and 3.265 Mcal of ME/kg, 0.60% lysine in the late-finishing phase and other nutrients met or exceeded NRC (1998) standards. Compared to the control diet (CON), lysine levels of experimental diets were restricted to 15% (treatment EL, EEL) or 30% (treatment ELL, EELL), whereas energy level of experimental diets was increased by 0.100 or 0.200 Mcal of ME/kg. A total of 100 crossbred pigs ([Yorkshire${\times}$Landrace]${\times}$Duroc), with average initial body weight of $58.47{\pm}1.42\;kg$, were allotted to 5 dietary treatments based on sex and body weight. Each treatment had 5 replicates with 4 pigs (two barrows and two gilts) per pen. ADG, ADFI and feed efficiency were calculated in an 8-week growth trial. In the late finishing period (5-8 weeks), pigs fed ELL or EELL diets had decreased ADG and feed efficiency (p<0.01), however, when the EEL diet was provided, a similar growth performance was observed compared to those fed the CON diet during the whole experimental period (p>0.05). In a metabolic trial, 15 pigs were used to evaluate the effect of dietary lysine restriction and energy density on nutrient digestibility. The digestibility of dry matter, crude fat and crude ash was not improved by restricting dietary lysine or energy density. However, crude protein digestibility was decreased (p<0.05) as dietary lysine was restricted. When dietary lysine was restricted, fecal nitrogen was increased whereas nitrogen retention was decreased. BUN concentration was affected by dietary lysine restriction; treatments ELL and EELL had higher BUN values than other treatments (p<0.01). Carcass characteristics and meat quality were measured when average body weight of pigs reached $107.83{\pm}1.50\;kg$. Treatment ELL had higher last rib backfat depth (p<0.05) than treatment CON, but ELL and EEL did not differ significantly. The ELL and EEL treatments had higher (p<0.05) subjective marbling score than treatment CON. Treatment EEL showed higher longissimus fat content than treatment EL and CON (p<0.01). The results indicated that finishing pigs fed a diet with 15% lysine restriction and 3.465 Mcal of ME/kg energy density had no detrimental effects on growth performance and N utilization, and could achieve substantial increases in marbling and longissimus fat content of pork.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.12
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• pp.1874-1879
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• 2007

A total of one hundred and forty four weaned pigs with an average BW of $8.09{\pm}0.05$ kg were used in a 28 day study to investigate the effects of fermented soy protein on growth performance, blood urea nitrogen and total protein concentrations in serum and nutrient digestibility in weaner pigs. Pigs were blocked by initial body weight and randomly allocated to one of four dietary treatments in a randomized complete block design. There were six replications per treatment. Dietary treatments included: SBM (corn-soybean meal basal diet), F 5, 10 and 15 (fermented soy product was used at 5, 10 and 15% to replace soybean meal in basal diet, respectively). ADG (average daily gain) and ADFI (average daily feed intake) were not affected (p>0.05) by dietary treatments during the entire 4-wk study period. There were linear increments in feed efficiency (p<0.01) as the dietary FSP level increased during the entire feeding period. No significant differences were observed for dry matter and nitrogen digestibility during the experimental period (p>0.05). Digestibilities of histidine, lysine and methionine were increased as the FSP level increased (linear effect, p<0.05, p<0.01). Among non-essential amino acids, alanine, glutamic acid, serine, tyrosine and total non essential amino acid digestibilities were increased linearly (p<0.05, p<0.01). There were quadratic effects in protein digestibility (p<0.05). Total amino acid digestibility of the F15 diet was improved compared with the F5 diet (p<0.05). There were no significant differences in fecal consistency score among the treatments (p>0.05). At the end of experiment, BUN (blood urea nitrogen) concentration was increased as the FSP level increased (linear effect, p<0.01) and total protein concentration was lowest (p<0.05) for pigs fed the SBM diet among treatments. In conclusion, the feeding of 10 or 15% FSP to nursery pigs improved feed efficiency, amino acid digestibility and blood urea nitrogen and total protein concentrations in blood.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.2
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• pp.267-274
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• 2009

Two experiments were conducted to investigate the feeding value of wood vinegar in weanling pigs. In Experiment 1, weanling pigs (n = 224; Landrace ${\times}$Yorkshire ${\times}$Duroc, 21${\pm}$3 d-old, initial BW 6.12${\pm}$0.10 kg) were assigned to four dietary treatments. Different levels of wood vinegar were added to the diets as dietary treatments (0, 0.1, 0.2 and 0.3%). Each treatment comprised 4 replicates with 14 piglets in each. Experimental feeding was conducted for 28 d in two phases (phase I, d 0 to 14 and phase II, d 15 to 28). Feeding of wood vinegar linearly (p<0.05) improved the phase I, phase II and overall ADG and increased (linear, p<0.05) the overall and phase II ADFI. Linear improvements in the apparent fecal digestibility of dry matter (p = 0.013), gross energy (p = 0.019) and crude protein (p = 0.033) were observed as the level of wood vinegar was increased in the diet of pigs. Experiment 2 was conducted to compare dietary wood vinegar with commonly used growth promoters, organic acid (mixture of 21% phosphoric acid, 3.25% propionic acid, 2.8% formic acid, 10% calcium formate and 5% calcium propionate) and antibiotic (aparamycin). A total of 288 weanling piglets (Landrace ${\times}$Yorkshire ${\times}$Duroc, 22${\pm}$2 d-old, initial BW 6.62${\pm}$0.31 kg) were assigned to four treatments with four replicates (18 piglets/pen) for 28 days and fed in 2 phases: phase I, d 0 to 14 and phase II, d 15 to 28. The dietary treatments were control (corn-soybean meal basal diet without antibiotics) and diets containing 0.2% antibiotic, 0.2% organic acid and 0.2% wood vinegar. Pigs fed antibiotic showed higher (p<0.001) ADG and better feed efficiency followed by pigs fed wood vinegar and organic acid diets while those fed the control diet had lowest ADG and poorest feed efficiency. The overall and phase I ADFI was highest (p<0.001) in pigs fed wood vinegar and lowest in pigs fed the control diet. Apparent fecal digestibility of dry matter, gross energy and crude protein was significantly higher (p<0.05) in pigs fed the antibiotic diet when compared with pigs fed the control but comparable among pigs fed antibiotic, organic acid and wood vinegar diets. Higher populations of Lactobacillus (p = 0.004) were noted in the ileum of pigs fed the wood vinegar diet, while the population of coliforms in the ileum and cecum was higher (p<0.001) in pigs fed the control diet when compared with pigs fed antibiotic, organic acid or wood vinegar diets. These results indicated that wood vinegar could improve the performance of weanling pigs by improving the nutrient digestibility and reducing harmful intestinal coliforms; moreover performance of pigs fed wood vinegar was superior to those fed organic acid.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.5
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• pp.445-454
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• 1997

Rice bran commonly available in Bangladesh is a mixture of rice hulls (60%), bran (35%) and polishing (5%), referred here as rice mill feed (RMF). Dose response effect of RMF supplementation to a straw diet including a zero level was measured on the intake, digestibility, nitrogen balance, microbial N yield and growth rate of growing native (Bos indicus) bulls. Twelve bulls of 33 months old and $272{\pm}31.5kg$ weight were randomly allocated to diets having 0 (T1), 1 (T2) and 2 (T3) kg RMF in addition to 200 g wheat bran, 200 g molasses, 60 g salt and 30 g oyestershe\l powder. Concentrate intake was 5.5, 19.2 and 29.5% of the dietary intake for the T1, T2 and T3 treatment respectively. RMF supplementation had no significant effect on the straw DM intake. However, with the increasing levels of RMF supplementation, total DM & digestible OM intake and the whole gut digestibilities of DM, OM, N & ADF increased but in deminishig return. Total microbial N yield estimated from the urinary purine excretion were 15.35, 26.56 and 38.44 g/d for the treatment T1, T2 and T3 respectively. Both the N intake and the N balance increased linearly in response to increasing level of RMF. Supplementation of RMF linearly increased the energy intake and dietary energy concentration. Growth rate in the T1, T2 and T3 treatments were 112, 125 and 250 g/d respctively. The basal N excretion and the maintenance energy requirement of the experimental animals were estimated to be 615 mg/kg $W^{0.75}/d$ and 447 kJ/kg $W^{0.75}/d$ respectively. The estimated efficiency on N utilization was 0.83 mg/mg of N intake ($r^2=0.997$) while the efficiency of metabolizable energy utilization for growth was 0.15. Since animal refused higher levels of RMF, inclusion up to 2 kg level (about 25% of the total DM intake) appears to have no depressing effect on the performances of animal. However, RMF itself fail to meet the critical nutrient need of the rumen microbes. Therefore response of supplementing RMF after correcting the critical nutrient deficiency need to be studied.

• Journal of Korean Society of Disaster and Security
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• v.13 no.2
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• pp.65-75
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• 2020

The efficiency of sewage treatment was ananlyzed selecting a sewage treatment plant in Gyeonggi-do where A₂O process was applied. Statistical techniques based on the operation data of the sewage treatment were used. The main factors directly affecting the efficiency of the treatment process were analyzed using a GPS-X model. The correlation analysis and one-way ANOVA were performed. The T-N and NH₄⁺-N values of the effluent did not generate statistically significant level (p-value:>0.05) when compared with C/N ration values. Removel of nitrogen components form sewage treatment plants were affected by temperature, HRT, SRT and DO. In the case of BOD, all operating factors were affected, while COD was affecte by factors of HRT, STR and DO. In simulations using GPS-X, the parameters that greatly influence was included the maximum sedimentation rate, the dependent nutrient microbial yield (anoxic), the phosphorus saturation coefficient, the dependent nutrient microbial killing rate, the dependent nutrient microbial maximum growth rate, and the independent trophic microorganisms. The maximum growth rate and the maximum setting rate were identified.

• Journal of Environmental Health Sciences
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• v.39 no.1
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• pp.83-89
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• 2013

Objectives: The purpose of this experiment was to illuminate the relationship between the phosphorus removal rate of unit operation and the phosphorus removal rate of phosphorus volume loading in the Ferrous Nutrient Removal process, which consists of an anoxic basin, oxic basin, and iron precipitation apparatus. Methods: This study was conducted in order to improve the effect of nitrogen and phosphorus removal in domestic wastewater using the FNR (Ferrous Nutrient Removal) process which features an iron precipitation reactor in anoxic and oxic basins. The average concentration of TN and TP was analyzed in a pilot plant ($50m^3/day$). Results: The removal rate of T-N and T-P were 66.5% and 92.8%, respectively. The $NH_3-N$ concentration of effluent was 2.62 mg/l with nitrification in the oxic basin even though the influent was 17.7 mg/l. The $NO_3$-N concentration of effluent was 5.83 mg/l through nitrification in oxic basin even though the influent and anoxic basin were 0.82 mg/l and 1.00 mg/l, respectively. The specific nitrification of the oxic basin ($mg.NH_3$-Nremoved/gMLVSSd) was 16.5 and specific de-nitrification ($mg.NO_3$-Nremoved/gMLVSSd) was 90.8. The T-P removal rate was higher in the oxic basin as T-P of influent was consumed at a rate of 56.3% in the anoxic basin but at 90.3% in the oxic basin. The TP removal rate (mg.TP/g.MLSS.d) ranged from 2.01 to 4.67 (3.06) as the volume loading of T-P was increased, Conclusions: The test results showed that the electrolysis of iron is an effective method of phosphorus removal. Regardless of the temperature and organic matter content of the influent, the quality of phosphorus in the treated water was both relatively stable and high due to the high removal efficiency. Nitrogen removal efficiency was 66.5% because organic matter from the influent serves as a carbon source in the anoxic basin.

• Horticultural Science & Technology
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• v.34 no.3
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• pp.405-413
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• 2016

Quinoa (Chenopodium quinoa Willd.) is a plant native to the Andean region that has become increasing popular as a food source due to its high nutritional content. This study determined the optimal photoperiod, light intensity, and electrical conductivity (EC) of the nutrient solution for growth and yield of quinoa in a closed-type plant factory system. The photoperiod effects were first analyzed in a growth chamber using three different light cycles, 8/16, 14/10, and 16/8 hours (day/night). Further studies, performed in a closed-type plant factory system, evaluated nutrient solutions with EC (salinity) levels of 1.0, 2.0 or $3.0dS{\cdot}m^{-1}$. These experiments were assayed with two light intensities (120 and $143{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) under a 12/12 and 14/10 hours (day/night) photoperiod. The plants grown under the 16/8 hours photoperiod did not flower, suggesting that a long-day photoperiod delays flowering and that quinoa is a short-day plant. Under a 12/12 h photoperiod, the best shoot yield (both fresh and dry weights) was observed at an EC of $2.0dS{\cdot}m^{-1}$ and a photosynthetic photon flux density (PPFD) of $120{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. With a 14/10 h photoperiod, the shoot yield (both fresh and dry weights), plant height, leaf area, and light use efficiency were higher when grown with an EC of $2.0dS{\cdot}m^{-1}$ and a PPFD of $143{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Overall, the optimal conditions for producing quinoa as a leafy vegetable, in a closed-type plant factory system, were a 16/8 h (day/night) photoperiod with an EC of $2.0dS{\cdot}m^{-1}$ and a PPFD of $143{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$.