• 농업과학연구
• /
• 제8권1호
• /
• pp.44-50
• /
• 1981

한국재래산양(韓國在來山羊)에 대(對)한 단백질(蛋白質)의 요구량(要求量)을 구명(究明)하기 위(爲)하여 생체종별(生體種別)로 단백질(蛋白質)의 급여수준(給與水準)에 차이(差異)를 두고 질소(窒素)의 축적율(蓄積率)을 측정(測定)하였고 혈청(血淸)의 단백질(蛋白質) 및 요소(尿素)의 함량(含量)을 조사(調査) 분석(分析)한 결과(結果)는 다음과 같다. l. 생후(生後) 8개월령(個月令)의 생체중(生體重) 14kg의 빈산양(牝山羊)에 대(對)하여 무단백질사료(無蛋白質飼料)를 급여(給與)하여 측정(測定)한 내인성요질소량(內因性尿窒素量)은 1일(日) 평균(平均) 1.29g이었으며, 내인성(內因性) 분질소량(糞窒素量)은 1.27g이었다. 따라서 1일(日) 최소(最少) 단백질(蛋白質) 요구량(要求量)은 22g이다. 2. 기온(氣溫)이 영하(零下) $10^{\circ}C$이하(以下)로 하강(下降)할때는 단백질수준(蛋白質水準)을 20%로 급여(給與)하여도 질소축적율(窒素蓄積率)이 부(負)를 나타내므로 energy의 소모량(消耗量)이 많은 것으로 추측(推測)된다. 3. 생체중(生體重) 20kg의 임신(姙娠)한 빈산양(牝山羊)의 질소(窒素) 축적율(蓄積率)은 17~20%로서 성장중(成長中)인 산양(山羊)에 비(比)하여 낮았다. 4. 혈청(血淸)의 단백질(蛋白質) 및 요소함량(尿素含量)은 단백질(蛋白質) 급여수준(給與水準)의 저하(低下)에 따라서 현저(顯著)하게 저하(低下)되었다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제14권9호
• /
• pp.1282-1289
• /
• 2001

One feeding trial and two metabolic trials were conducted to investigate the effects of lysine to protein ratio in practical swine diets on growth performance and efficiency of nitrogen retention and utilization in different growing phases. In Trial one (the feeding trial), 90 mixed sex pigs weighing $9.1{\pm}1.4kg$ (Duroc ${\times}$ Landrance ${\times}$ Beijing Black) were used to study the effects of concentrations of 5.2, 5.3, 5.8, 6.4 and 7.2 g lysine/100 g CP in diets containing 1.2% lysine on growth performance and serum urea nitrogen. The results showed that feed conversion efficiency and economic efficiency were best for pigs fed the diet containing the lysine concentration of 5.8 g /100 g crude protein. Serum urea nitrogen concentration decreased linearly (p=0.0009) and serum free lysine content increased linearly (p=0.0017) as the lysine to protein ratio in diets increased from 5.2 to 7.2 g/100 g. In Trials two and three (the metabolic trials), five growing barrows (Duroc ${\times}$ Landrance ${\times}$ Beijing black), with initial body weights of approximately $26{\pm}2.4kg$ and $56.3{\pm}3.5kg$, respectively, were allotted to five dietary treatments according to a $5{\times}5$ Latin square design. Trial two contained 5.2, 5.7, 6.1, 6.7 and 6.8 g lysine/100 g CP treatments. Trial three contained 4.6, 5.0, 5.6, 6.1 and 6.6 g lysine/100 g CP treatments. The results showed that nitrogen retention in growing pigs decreased linearly (p=0.0011 in Trial two; p=0.0099 in Trial three) as the lysine to protein ratio in diets increased. The ratio of lysine to protein in diets resulting in maximum nitrogen retention was 5.2 g/100 g and 5.0 g/100 g in Trial two and Trial three, respectively. In Trial two, apparent biological value and gross nitrogen efficiency increased linearly (p=0.0135 and p=0.0192, respectively) as the lysine to protein ratio increased from 5.2 to 6.8 g lysine/100 g CP. In summary, we concluded that the optimal Lysine to Protein Ratios for 8-20 kg and 20-80 kg pigs were 5.8 g/100 g and 5.0 to 5.2 g/100 g, respectively.

• 상하수도학회지
• /
• 제24권1호
• /
• pp.5-14
• /
• 2010

A pilot-scale biological aerated filter (BAF) was operated with an anaerobic, anoxic and oxic zone at $23{\pm}1^{\circ}C$. The influent sCOD and total nitrogen concentrations in the feedwater were approximately 250 mg/L and 35 mg N/L, respectively. sCOD removal at optimum hydraulic retention time (HRT) of 3 hours with recirculation rates of 100, 200 and 300% in the column was more than 96%. Total nitrogen removal was consistently above 80% for 4 and 6 hours HRT at 300% recirculation. For 3 hours HRT and 300% recirculation, total nitrogen removal was approximately 79%. Based on fitting results, the kinetic parameter values on nitrification and denitrification show that as recirculation rates increased, the rate of ammonia and nitrate transformation increased. The ammonium loading rates for maximum ammonium removed were 0.15 and 0.19 kg $NH_3$-N/$m^3$-day for 100% and 200% recirculation, respectively. The experimental results demonstrated that the BAF can be operated at an HRT of 3 hours with 200 - 300% recirculation rates with more than 96 % removal of sCOD and ammonium, and at least 75% removal of total nitrogen.

• The Korean Journal of Ecology
• /
• 제19권2호
• /
• pp.179-189
• /
• 1996

Growth and nitrogen retention of Persicaria thunbergii were investigated in the wetland microcosms which contained the plants growing on soil bed. Nitrogen solution was supplied to the microcosms with the same amount of $NH_4^{+}-N\; and\; NO_3^{-}-N$ at the rates of 0.00, 0.78, 1.57, 3.14g $N{\cdot}m^{-2}{\cdor}wk^{-1}$ from May 1 to August 31, 1995. The solution was detained for 5 days to react with soil and plant and then allowed to leach. The contents of NH_4^{+}-N\;and\; NO_3^{-}-N$ in the leachate, total Kjeldahl nitrogen, plant biomass, and soil characteristics were determined. Nitrogen retained by plant was estimated as the increment of TKN in plant biomass. The addition of 0.78 and 1.57g $N{\cdot}m^{-2}{\cdot}wk^{-1}$ resulted in significant increase of plant biomass. However, plant growth was inhibited when nitrogen was added at the rate of 3.14g $N{\cdot}m^{-2}{\cdot}wk^{-1}$. Overall, the plant biomass was positively correlated with the amount of nitrogen retained by plant and soil system. The amounts of $NO_3^{-}-N$ leached from the microcosms were 5~10 times higher than those of $NH_4^{+}-N$. While total nitrogen added ranged from 143.2 to 576.5g $N/m^2$, total leaching loss of inorganic nitrogen and nitrogen retained by plant was as little as 1.04~22.71g $N/m^2$, and 5.46~12.91g $N/m^2$, respectively. Then, the plant seemed to contribute to KDICical and microbial immobilization of nitrogen in the soil. Finally, it is suggested that a large portion of nitrogen added was lost into the air by denitrification and volatilizaton, and / or leached in organic forms.

• Journal of Animal Science and Technology
• /
• 제58권5호
• /
• pp.21.1-21.8
• /
• 2016

Background: The aim of the present study was to determine the effects of feeding trace mineralsfortified mixed microbial culture (TMC) on ruminal fermentation, nutrient digestibility, blood electrolyte status, nitrogen balance, and trace mineral balance in sheep. Methods: Mixed microbes [0.6 % (v/w) of Enterobacter sp., Bacillus sp., Lactobacillus sp., and Saccharomyces sp.] were cultured with 99 % feedstuffs and 0.4 % trace minerals including zinc and copper for ensiling. Six sheep (a mean body weight of $46.5{\pm}1.2kg$) were fed two diets: a control diet (concentrate mix and rye straw) and an experimental diet (a control diet + 3.1 % TMC). Results: TMC feeding did not induce negative effects on ruminal fermentation, nutrient digestibility, blood electrolytes, and nitrogen balance in sheep. Feeding with TMC increased the intake of trace minerals (p < 0.05) and did not affect absorption of trace minerals in the whole digestive tract. Feeding with TMC increased fecal excretion and absorbable intake, and retention of zinc and copper (p < 0.05) by 71 % and 77 %, respectively. Conclusion: Feeding with TMC resulted in higher zinc and copper bioavailability and retention without any adverse effects on sheep performance.

• Asian-Australasian Journal of Animal Sciences
• /
• 제15권9호
• /
• pp.1288-1293
• /
• 2002

Four adult rams ($22.25{\pm}0.90kg$) were used in a $4{\times}4$ latin square design to evaluate the rations without ($T_1$) or with supplementation of sunflower acid oil at 5 ($T_2$), 10 ($T_3$) or calcium soap at 10% of dietary DM ($T_4$) on nutrient digestibility and balances of nitrogen, calcium and phosphorus. The basal ration contained 60 parts Brazilian napier grass hay and 40 parts concentrate mixture. The DM, CF, NDF and ADF digestibilities and nitrogen retention (g/d) decreased (p<0.01) by inclusion of sunflower acid oil at 5% of dietary DM. In addition, depression (p<0.01) in digestibilities of CP, nitrogen free extract (NFE), cellulose, hemicellulose, retention of calcium and phosphorus (g/d) were also observed with increasing the level of sunflower acid oil to 10% of dietary DM. The EE digestibility, total digestible nutrients (TDN) content and calcium retention (g/d) were significantly higher (p<0.01) for ration supplemented with calcium soap. It is concluded that sunflower acid oil supplementation in free form as low as 5% of dietary DM is deleterious to fibre digestion in sheep while as calcium soap, it can be fed up to 10% of dietary DM as an energy source without any adverse effect.

• 한국환경과학회지
• /
• 제28권8호
• /
• pp.669-676
• /
• 2019

The purpose of this study was to evaluate the effects of different Hydraulic Retention Times (HRTs) on the contaminant removal efficiency using Aerobic Granular Sludge (AGS). A laboratory-scale experiment was performed using a sequencing batch reactor, and the Chemical Oxygen Demand (COD), nitrogen, orthophosphate removal efficiency, AGS/MLSS ratio, and precipitability in accordance with the HRT were evaluated. As a result, the COD removal efficiency was not significantly different with the reduction in HRT, and at a HRT of 6 h, the removal rate was slightly increased owing to the increase in organic loading rate. The nitrogen removal efficiency was improved by injection of influent division at a HRT of 6 h. As the HRT decreased, the MLSS and AGS tended to increase, and the sludge volume index finally decreased to 50 mL/g. In addition, the size of the AGS gradually increased to about 1.0 mm. Therefore, the control of HRT provides favorable conditions for the stable formation of AGS, and is expected to improve the contaminant removal efficiency with the selection of a proper operation strategy.

• 한국습지학회지
• /
• 제17권4호
• /
• pp.414-420
• /
• 2015

질소는 수계 부영양화를 유발하는 주요 원인이며, 수계 보호를 위해 반드시 처리해야 하는 오염물질이다. 본 연구에서는 고농도 질소를 처리하여 하수처리장 운전 효율 증대를 위한 방안을 연구하고자 하였다. 약 250일간 하수처리장 농축조상징액을 이용하여 실험실 규모 반응조를 운전하였다. 실험실 반응조 운전은 안정적인 아질산화 반응을 유도하고, 관련 운전 인자 영향을 분석하고자 하였다. 연구 결과 체류시간 조절을 통해 인위적으로 아질산화 반응이 유도가능한 것을 확인하였으며, 안정적인 아질산화 반응이 유도되는 구간을 파악하였다. 특히, 체류시간 1일 조건에서는 90%에 가까운 고효율의 아질산화율을 보이는 것을 확인하였다. 특히 ammonium nitrogen load는 암모니아성 질소 제거율과 아질산화율에 영향을 미치는 것으로 나타났다. 높은 ammonium nitrogen load 조건에서는 아질산화율과 암모니아성 질소 효율이 감소하였다. 반면, 낮은 ammonium nitrogen load 조건에서는 아질산화율이 감소하는 것으로 나타났다. 이는 아질산화 반응을 위해 암모니아성질소 농도 및 체류시간의 조절이 필요하다는 것을 의미한다. 농축조 상징액과 같은 슬러지 처리 공정 내 고농도 질소를 함유한 폐수는 아질산화 반응을 적용할 수 있으며, 이는 하수처리장 개조 방안으로 제안 될 수 있을 것으로 판단된다.

• Journal of Nutrition and Health
• /
• 제16권4호
• /
• pp.273-280
• /
• 1983

The effect of alteration of light-darkness cycle on the protein metabolism was studied in the rat. The light-darkness cycle was altered either every 3 or 9 days, and animals consumed diets containing 8 or 25% casein. The results were summarized as follows : 1) Food consumptions and body weight gains of the 25% casein groups were higher than those of the 8% casein groups, and, among the animals consumed 25% casein diet, the light-darkness cycle altered group had lower food consumption and body weight gain than the unaltered group. 2) Weights of liver and adrenal gland per l00g body weight were not different with the dietary protein levels, but, at the end of experimental period, the 8% casein diet group of which light-darkness cycle altered every 9 days had the smallest liver weight and the largest adrenal gland weight. 3) Liver nitrogen and plasma protein concentrations of the 25% casein groups were slightly higher than those of the 8% casein groups. 4) Percentages of nitrogen retention of the 25% casein groups at period III were slightly lower in the light-darknerr cycle altered animals than that of the unaltered group.

• Journal of Nutrition and Health
• /
• 제24권1호
• /
• pp.20-29
• /
• 1991

This study was carried out to compare the protein quality of lamb and beef meat. by feeding to growing rats. Sixty weanling rats, 30 males and 30 females, were blocked into 12 groups(6 gruops of males and 6 groups of females). They were fed casein. beef, or lamb as a protein source at two levels, 6 and 15%, for 5 weeks. The amount of food intake. food efficiency ratio, protein efficiency ratio. body weight gain. and the weights of skeletal muscles and liver were measured. Nitrogen retention, protein content in the liver and skeletal muscles, and the levels of protein and cholesterol in the serum were also assayed. Summarzing the results, there were no significant differences between lamb and beef on the growth and nitrogen utilization in the rats fed same percentage of protein diet. However. rats fed 15% protein diet showed significantly higher growth rate than those fed 6%. Therefore, it can be concluded that lamb is as good a protein food as beef in terms of protein quality.