• KSBB Journal
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• v.16 no.3
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• pp.314-319
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• 2001

A nitrifier consortium immobilized in polyvinyl alcohol was used to remove ammonia nitrogen from synthetic wastewater in an airlift bioreactor. The minimum aeration rates were 0.4, 0.6, 0.8 and 1.0 vvm for 5, 10, 15 and 20% immobilized bead packing volume fraction, respectively. The efficient packing fraction and the aeration rate for ammonia nitrogen removal were 15% and 2.4 vvm, respectively. With a hydraulic retention time of 0.5hr, the removal rate and the efficiency of ammonia nitrogen removal were 1685 g/㎥$.$day and 48% at an influent ammonia nitrogen concentration of 75 g/㎥.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.4
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• pp.673-679
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• 1992

To investigate the effects of molasses addition at ensiling on nutritional quality of wilted napier grass, chemical quality and nutrient composition of the silages, digestibility and nitrogen retention at feeding trials were analysed using 4 goats in a cross over design. The results are as follows : 1. Molasses addition at ensiling decreased pH value (3.99) and ammonia nitrogen, and increased lactic acid content by 285% compared to non-additive silage (83.5 g/kg dry matter). 2. There were no differences in digestibilities of dry matter, crude protein, neutral detergent fiber, acid detergent fiber, hemicellulose and cellulose between the silage ensiled with molasses (MS silage) and the silage ensiled without molasses (WS silage). Urinary nitrogen excretion, however, significantly (p<0.05) decreased in goats fed the MS silage, and nitrogen retention was positive in goats fed the MS silages, but negative in goats fed the WS silage. 3. Acetic acid concentration in remained fluids in goats fed the MS silage was lower and propionic and butyric acid concentrations were higher than those in goats fed the WS silage. As water soluble carbohydrate content was higher in the MS silage than in the WS silage, a part of added molasses was still remained in the silage at the feeding trials and could be utilized for energy sources by the goats. Nitrogen may be also effectively utilized in goats fed the MS silage, because the silage were inhibited in proteolysis during ensiling.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.4
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• pp.601-605
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• 1993

This study was purposed to investigate the efficiency of protein utilization of rapeseed meal (RSM) and formaldehyde-treated RSM (TRSM) by sheep, and their influence on performance of growing heifers. Experiment 1 was conducted according to a double $3{\times}3$ Latin square design involving sex yearling Hu Sheep and three experimental diets. All diets contained 600 g ammoniated rice straw and 200 g concentrate mixture. Three dietary treatments were: (1) 100 g RSM + 40 g soybean meal (URUS), (2) 100 g TRSM + 40 g soybean meal (TRUS) and (3) 100 g TRSM + 40 g treated soybean meal (TRTS). Apparent nitrogen digestibility was significantly higher for diet TRUS than that for URUS or TRTS (p<0.05), but with no significant difference between URUS and TRTS (p>0.05). Proportion of nitrogen retention (NR) to the digestible nitrogen intake for diet TRUS and TRTS was 25.57 (p<0.05) and 23.44% (p<0.05) higher than that for URUS respectively. As a result, proportion of NR to nitrogen intake for diet TRUS and TRTS was 34.74 (p<0.05) and 23.78% (p<0.05) higher than that for URUS respectively. Experiment 2 was conducted with 59 Holstein heifers. They were 12-20 months of age at the start of the trial. The experiment was a $2{\times}2$ factorial trial in which the heifers were given the ammoniated rice straw ad libitum and 1.5 kg hay, and supplemented with either RSM or TRSM at a daily allowance of 1.2 or 1.8 kg per day. The live weight gains for heifers receiving 1.2 and 1.8 kg/d of RSM or TRSM were 0.491 and 0.556 or 0.564 and 0.665 kg/d, respectively. The results suggest that formaldehyde treatment can effectively improve the efficiency of protein utilization of rapessed meal and cattle's performance.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.1
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• pp.45-51
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• 1993

With the purpose to utilize cage layer manure (CLM), whole crop corn forage was ensiled with 30% CLM (MS silage) and without CLM (CS silage). MS silage was significantly (p < 0.05) higher in pH value, total VFA, propionic and butyric acids, and the ratio of ammonia nitrogen to total nitrogen, but lower (p < 0.05) in lactic acid and water soluble carbohydrate (WSC) contents than CS silage. Digestibility was evaluated using Shiba strain Japanese goats. Urea was supplemented to CS silage at feeding to adjust nitrogen intake to MS silage (US silage). There were no differences in digestibilities of dry matter (DM) and energy among the three silages. However, US silage showed higher (p < 0.05) digestibility of crude protein, but digestibilities of NDF, ADF, hemicellulose and cellulose were higher (p < 0.05) in MS silage. Nitrogen retention was positive in US and MS silages, but it was negative in CS silage. Voluntary feed intake of goats was 11.02, 12.03 and 13.34 g of DM per metabolic body weight ($kg^{0.75}$) for 10 minutes, for CS, US and MS silages, respectively.

• Journal of Nutrition and Health
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• v.28 no.4
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• pp.291-297
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• 1995

This study aimed to verify the nutritional and curative effects of protein hydroysate in rats model with gastric ulcer induced by restraint and water-immersion stress. Sprague-Dawley, famale rats weighing approximtely 200g were forced in 5$\times$5$\times$15cm plexiglas cage. The restraint and water immersion stress was carried at 20$\pm$2$^{\circ}C$ for 8-hours. After stress 4 kinds of diets(10% casein, 20% casein, 10% casein hydrolysate, 20% casein hydrolysate) were given for 5 days. In the gastric ulcer rats model, the growth, gastric emptying rate, trypsin activity in gastrointestinal content, plasma total protein, albumin, $\alpha$-amino-N, UUN, creatinine and hydroxyproline of the urine and nitrogen retention were analyzed for nutritional effects of dietary nitrogen levels(10%, 20%) and sources (casein, casein hydrolysate). The results were as follows ; In gastric ulcer rats model, severeness of ulcer, plasma protein, gastric emptying rate, nitrogen retention rate were not different between 20% casein-fed group and 20% casein hydrolysatefed group. But 10% casein hydrolysate-fed group had more curative group. The casein hydrolysate diet-fed group was lower trysin activity in small intestianl content than the casein-fed group, at both casein level(10%, 20%). Finally at 20% levels, there was no difference between casein and casein hydrolysate diet, but 10% level, casein hydrolysate diet was more curative of ulcer than casein diet in gastric ulcer rat model. The results of this study provide useful information concerning diet therapy for the patients with gastrointestinal diseases and the field of enteral diet materials.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.3
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• pp.238-244
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• 2015

Three growing wethers were used to investigate the differences in nitrogen (N) retention, blood plasma metabolite concentration and energy-yielding nutrient supply to muscle and adipose tissue. The wethers were fed one of three diets: timothy hay with concentrate (THD), Italian ryegrass with concentrate (IRD), and rice straw with concentrate (RSD) for 11 days. The experimental diets were adjusted to the animals to provide 100 g of daily gain. The triglyceride (TG) concentration of blood plasma in arterial and portal veins was higher with THD and IRD than with RSD. Conversely, the available amount of TG in tissues was higher with IRD. The daily amount of glucose and non-esterified fatty acids (NEFA) supplied to muscle tissue and adipose tissue was numerically higher with THD than IRD or RSD. Although N retention did not differ among the diets, it was numerically higher with THD than with IRD or RSD. The results suggest that the difference in the amount of glucose and NEFA delivered to muscle tissue may reflect the N retention in response to forage based diets.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.6
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• pp.797-803
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• 2017

Objective: Effects of nitrogen supplementation associated with different levels of starch on voluntary intake, digestibility, and rumen and metabolic characteristics of cattle fed low-quality tropical forage (Brachiaria decumbens hay, 7.4% crude protein, CP) were evaluated using ruminal and abomasal cannulated steers. Methods: Five European${\times}$Zebu young bulls (186 kg body weight, BW) were distributed according to a $5{\times}5$ Latin square. The following treatments were evaluated: control, supplementation with 300 g CP/d (0:1), supplementation with 300 g starch/d and 300 g CP/d (1:1), supplementation with 600 g starch/d and 300 g CP/d (2:1), and supplementation with 900 g starch/d and 300 g CP/d (3:1). A mixture of nitrogenous compounds provided 1/3 from true protein (casein) and 2/3 from non-protein nitrogen (mixture of urea and ammonium sulphate, 9:1) was used as the nitrogen supplement. In order to supply energy a unique source of corn starch was used. Results: Supplements increased (p<0.05) dry matter intake, but did not affect (p>0.05) forage intake. There was a cubic effect (p<0.05) of starch on voluntary intake. This was attributed to the highest forage intake (g/kg BW) when using the 2:1 starch:CP ratio. Supplements increased (p<0.05) organic matter (OM) digestibility, but did not affect (p>0.05) neutral detergent fibre corrected for ash and protein (NDFap) digestibility. There was a positive linear effect (p<0.05) of the amount of starch supplemented on OM digestibility. Total NDFap digestibility was not affected (p>0.05) by the amount of supplemental starch. Ruminal ammonia nitrogen concentrations were higher (p<0.05) in supplemented animals, however, a negative linear effect (p<0.05) of amount of starch was observed. Supplements increased (p<0.05) the nitrogen balance (NB) and efficiency of nitrogen utilization. These effects were attributed to increased body anabolism, supported by higher (p<0.05) serum concentration of insulin-like growth factor 1. Increasing the amount of starch tended (p<0.06) to linearly increase the NB. In spite of this, there was a highest NB value for the 2:1 starch:CP ratio amongst the treatments with supplementation. Conclusion: Nitrogen supplementation in cattle fed low-quality tropical forage increases nitrogen retention in the animal's body. An additional supply of starch increases nitrogen retention by increasing energy availability for both rumen and animal metabolism.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.4
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• pp.341-350
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• 2008

This trial was conducted to investigate effects of different feeding types of conventional or total mixed rations (TMR) provision on feed intake, nutrient digestibility, nitrogen retention and blood metabolite characteristics in different breeds of native and cross bred Korean black goats. Ten Korean native male goats and 10 Korean crossbred black male goats (Korean native $\times$ Australian feral crossbred, 50:50), average 18 kg of BW, were used in this trial, and each breed of Korean black goats was separated into conventional and TMR diets treatments in a randomized complete block design. Conventional diet was based on forages and commercial diet. All animals were housed in individual metabolism crates and were fed ad libitum. Water was available at all times. Experimental period totally lasted for 38 days, consisting of 14 days of adaptation, 10 days of preliminary period and 14 days of sample collection period. Daily dry matter intake was significantly (p<0.05) higher in TMR treatments of the crossbred goats. Within breeds, crossbred rather than native-bred consumed more highly, and within the feeding type, TMR diets were more fed in comparison with conventional diet. Average daily gain ranked the highest in crossbred : TMR, followed by crossbred: conventional diet, native-bred: TMR, and native-bred: conventional diet (p<0.05). Dry matter digestibility was significantly (p<0.05) higher for TMR than for conventional diets, and it was higher in crossbred than in native-bred Korea black goats. Nitrogen retention was highest in TMR treatments of crossbreed, whereas it was lowest in conventional diet of native breed (p<0.05). Plasma glucose and urea nitrogen concentrations were significantly (p<0.05) higher in crossbred than in native-bred Korean black goats. Overall, the results indicated that feeding total mixed ration to crossbred rather than native-bred Korean black goats had more favourable influences on their performances, intakes, digestibility, nitrogen retention and blood metabolite characteristics. In conclusion, it is conceived that the results may contribute to economical benefit to farms producing Korean black goats together with establishment of an efficient feeding management system.

• Proceedings of the Korean Environmental Health Society Conference
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• 2003.06a
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• pp.144-146
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• 2003

The removal effect of total nitrogen in municipal wastewater by decreasing hydraulic retention time(HRT) from 6 hour to 4 hour on MNR process was not decreased.. The removal efficiencies of nutrient removal process combining A2/O process with media for T-N were 63.1% in the reactor operated 6 hour, and 73.5% in the reactor operated 5 hour and 77.0% in the reactor operated 4 hour.

• Journal of environmental and Sanitary engineering
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• v.11 no.3
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• pp.63-68
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• 1996

This study was to discuss limiting factors influenced on the removal efficiencies of nitrogenous compounds investigated using the polypropyrene media which was to attach microorganism in order to apply the fixed-biofilm process. The main limiting factors are the hydraulic retention time (HRT), C/N ratio, $COD/NO_{3}-N$ ratio and temperature. The hydraulic retention time HRT were 6, 8, 10, 12 hrs and the C/N ratio range was 2.5-9.5. The $COD/NO_{3}-N$ ratio range was 3.2-21.9 and the temperature were 15, 20, 25, 30, $35^{\circ}C$, respectively. The results of this study are summerized as follows. 1. Hydraulic retention time (HRT) to obtain removal efficiencies of T-N higher than 85% had to be 10 hrs above. 2. The removal efficiencies of T-N decreased at C/N ratio from 6.2 to 4.8 in this anoxic-contact aeration system. 3. Denitrification rate decreased at $COD/NO$_{3}$-N$ ratio from 8.0 to 5.0 4. As temperature increased, removal efficiencies of T-N increased.