• Asian-Australasian Journal of Animal Sciences
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• 제7권1호
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• pp.137-145
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• 1994

Amino acid (AA) substituted diets had no influence on rumen levels of total volatile fatty acids (VFA), ammonia and ${\alpha}$-amino-N, but tended to increase molar proportions of isovalerate and counts of total viable AA utilizing and celluloytic bacteria in the rumen as compared with the control urea diet. The AA diets did not affect daily flow to the duodenum of dry matter (DM), organic mater (OM) and acid detergent fibre (ADF), and rumen digestibility of these nutrients. However, the AA diets, in particular the 10 essential AA (EAA) diet improved total digestibility of DM, OM and ADF by decreasing faecal output of these fractions. Although N flow to the duodenum and N retention were not affected with the dietary treatments, duodenal bacterial flow appeared to increase by the AA diets when it was estimated by means of 2,6-diaminopimelic acid (DAP) and nucleic acid-purine bases (PB) as markers. The results suggest that AA supplements to a urea diet could improve feed utilization by stimulating microbial activity and proliferation in the rumen but and increased microbial activity per se is not necessarily associated with improvement of feed conversion.

• Asian-Australasian Journal of Animal Sciences
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• 제16권10호
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• pp.1482-1486
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• 2003

In order to compare effects of feeding systems on rumen fermentation characteristics and nutrient digestion, steers were fed either total mixed ration (TMR) or separate concentrate-roughage ration (CR). Total tract digestibility of nutrients was higher in steers receiving TMR. Especially, DM, ADF and NDF in TMR were digested to a greater extent than those in CR. Rumen pH was not influenced by the feeding systems. Holstein steers on TMR had higher ruminal $NH_3$-N than those on CR. Feeding system did not alter VFA production but TMR feeding resulted in lower A/P ratio. TMR feeding tended to increase the number of bacteria and protozoa in the rumen fluid. Also steers fed TMR generally had higher fiber degrading enzyme activities, which might be the result of increased number of cellulolytic microbes in the rumen of animals on TMR. Our results indicate that TMR may provide more favorable condition for nutrient digestion both in the rumen and in the total tract of steers.

• Asian-Australasian Journal of Animal Sciences
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• 제19권2호
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• pp.273-279
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• 2006

The performance of an autothermal thermophilic aerobic digestion (ATAD) system was studied to determine if nitrogen loss, as ammonia, was affected by an exhaust gas condenser. The system was run with and without a condenser while treating $8m^3$ of piggery slurry for 8 days. The system with a condenser (SWC) maintained the reactor temperatures above $40^{\circ}C$ for 2 days during the 8 days run, while the system without a condenser (SWOC) remained above $40^{\circ}C$ for 6 days. The SWC maintained the reactor temperatures mostly at mesophilic conditions while the SWOC at thermophilc conditions. Differences in operation conditions for the two runs were mainly caused by differences in atmospheric temperatures. Soluble chemical oxygen demand (SCOD) and volatile solids (VS) removal efficiencies of the SWC (SCOD: 62%, VS: 41%) were higher than those of the SWOC (SCOD: 40%, VS: 20%). The total Kjeldal nitrogen (TKN) removal efficiency of the SWC (7%) was less than that of the SWOC (25%). The concentration of total volatile fatty acids (VFA) in the SWC was observed to be lower than the threshold value of 0.23 g total VFA/L after 6 days, while the SWOC progressed below the threshold value after 3 days. No offensive odor emissions were observed in either run, which suggest that the use of the ATAD system may be a good odor removal strategy.

• 유기물자원화
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• 제21권3호
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• pp.64-73
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• 2013

가축분뇨 처리시스템에 대한 환경영향을 분석하기 위하여 전과정 평가방법을 적용하였다. 전과정평가의 첫 번째 부분은 사용될 분석 항목을 구성하는 것으로, 가축분뇨 처리시스템에 대한 유입 및 배출에 대한 항목이다. 전과정 영향평가를 위한 다음 단계로서 전체 환경부하를 최종적으로 하나의 지수로 통합하기 위하여, 특정 항목에 대한 자료를 취합하고 분석하는 것이다. 전과정 영향평가를 위해, Eco-indicator 95 방법은 체계화 되었으며, 규칙적으로 적용된 영향평가 방법이기 때문에 선택하였다. 전과정 영향 분석을 위한 실례로서 호기 및 혐기소화 시스템과 같은 두 종류의 돈분 처리시스템을 선정하였다. 돈 분뇨 처리시스템에 대한 농업환경영향을 평가한 항목을 확립하였고, 혐기소화시스템에서는 전 인산 배출이 높았으며, 호기소화시스템에서는 이산화탄소 배출이 높은 것으로 관측되었다. 돈분 1ton을 처리하는데 관련된 돈분처리시스템에 대한 환경영향 평가에서 Eco-indicator 수치에 따르면, 호기소화 시스템에 있어 지구온난화 및 토양산성화에서 음의 지수를 보인 반면 혐기소화시스템은 수계 부영양화 부분에서 비교적 높은 양의 지수를 보였다.

• 대한환경공학회지
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• 제28권11호
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• pp.1207-1212
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• 2006

본 연구는 담수 퇴적물 중 유기물의 척도가 되는 화학적산소요구량, 염양염류인 총질소와 총인 및 금속류인 철과 망간에 대해 국내 외 분석법을 적용하여 분석을 실시함으로서 각 분석법간의 상관성을 파악하고 그 적용성을 알아보고자 하였다. 화학적산소요구량은 국내 해양환경공정시험방법과 일본의 위생시험법을 적용하였는데 두 방법 모두 측정범위가 넓고, 생물학적산소요구량이나 유기물질과 상관관계가 좋은 과망간산칼륨법을 이용하고 있기 때문에 분석법간 편차가 크지 않음을 확인하였다. 총질소와 총인의 경우 국내 식품공전에 의한 시험법과 일본의 위생시험법을 적용하여 분석을 실시하였다. 총질소는 두 방법 모두 중화 적정법이지만 시료 분해 및 증류 과정의 차이에 의해 일본의 위생시험법에 의한 분석 값이 약간 낮은 경향을 보였다. 총인의 경우 두 방법 모두 질산과 과염소산에 의한 분해 후 값을 측정하는 방법으로 비슷한 결과를 보였다. 철과 망간과 같은 금속류의 실험은 크게 용출방법과 산분해법을 실시하였다. 용출법에서 얻은 결과값은 산분해한 값에 비하여 적은 값을 나타내었는데 그 이유는 용출조건보다 산분해 조건에서 금속류가 더 잘 녹아나오기 때문이다.

• Asian-Australasian Journal of Animal Sciences
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• 제24권7호
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• pp.965-973
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• 2011

Our objective was to determine the differences in the rate and extent of dry matter digestion between barley subjected to differing agronomic variables. Two malting barley varieties, Copeland and Metcalfe were seeded at rates of 200 and 400 plants/$m^2$. Each of these varieties received nitrogen fertilizer at rates of 0, 30, 60 and 120 kg/ha, resulting in a total of 20 different barley grain samples. Samples were ground through a 6mm screen and approximately 3 g of each weighed into 50 ${\mu}m$ Dacron bags and sealed. The bags were incubated in three ruminally cannulated Holstein cattle for periods of 0, 3, 6 and 24 h. Using the data obtained from these incubations, rates of digestion were able to be predicted. The soluble fraction ranged from 0.229-0.327, the slowly degradable fraction ranged from 0.461-0.656, and the undegradable fraction ranged from 0.038-0.299. The rates of digestion ranged from 0.127-0.165 $h^{-1}$ and the effective degradability ranged from 0.527-0.757. At the Canora location, the Copeland samples which received 120 kg/ha of nitrogen fertilizer had a significantly lower (p = 0.013) soluble fraction than the rest of the samples at that location. A significant interaction (p = 0.009) was seen between the seeding rate and nitrogen fertilizer application with samples from the Canora location, as well as significant differences (p = 0.029) between nitrogen application rates in samples from the Indian head location. The rate of digestion of samples from the Indian head location differed (p = 0.020) between the two seeding rates, with samples seeded at 200 seed/$m^2$ having a slightly higher rate of degradation. Differences in the effective degradability were seen between the different nitrogen application rates with samples from both the Canora and Indian head locations, as well as an (p = 0.004) interaction between the seeding rate and nitrogen fertilizer application rate. Although there was not a clear correlation between the different variables, both nitrogen application and seeding rate did have a significant effect on the rates and extent of digestion across each of the four locations.

• 한국토양비료학회지
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• 제34권3호
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• pp.165-172
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• 2001

가축사육으로 인해 매년 막대한 가축분이 발생하고 있으며, 그 처리방안 또한 여러 가지로 모색되고 있는 실정이다. 그러나, 밭농사를 영위함으로 인해 질소비료를 대체할 수 있는 가축분(돈분, 계분)의 양을 소화능으로 계산해 보았으며, 그 얻은 결과는 다음과 같다. 1. 우리나라의 가축분 발생량은 2000년도 기준으로 볼 때 년간 돈분 4,592,375톤, 계분 4,488,166톤이며, 이것을 질소 비료성분으로 환산할 경우, 돈분은 41,911톤, 계분 76,222톤의 질소비료성분에 해당하는 양이다. 2. 가축분 소화능이란 "토양에 가축분을 시용했을 때 토양자체가 역기능을 발휘하기 바로 직전까지의 최대소화량"이라고 정의 하였으며, 밭토양의 가축분 소화능계산 방법은 아래 식을 이용하여 계산하였다. 밭토양의 질소비료 대체 가축분 소화능(kg/10a) = 작물별 질소 표준시비량 / [(가축분중 T-N함량)${\times}$(가축분의 질소비효가용화율)] 3. 밭토양의 년간 질소비료 대체가능 가축분 소화능은 돈분 1,142.gkg/10a, 계분540.9 kg/10a으로 평가되었다. 4. 밭농사의 가축분 소화능의 작목별 기여도는 채소 > 과수 > 잡곡 > 맥류 > 서류 )> 두류 > 특작 > 초지 > 뽕밭 순이었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권3호
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• pp.11-21
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• 2022

The purpose of this study was to evaluate the influences of digestion temperature on the extraction of heavy metals from soil using the standard method established by Korean Ministry of Environment (KMES). A total of 7 heavy metals (As, Cd, Cr, Cu, Ni, Pb and Zn) in soil samples were extracted at varying digestion temperatures [(66 ± 2.0)℃, (73 ± 1.9)℃, (80 ± 1.3)℃, (85 ± 1.7)℃, (92 ± 2.0)℃, (98 ± 1.7)℃]. As, Cd, Cu, Pb and Zn concentrations remained relatively constant over the temperature range, but Ni and Cr concentrations greatly varied with the digestion temperature. The extent of variation in extraction efficiencies as compared to the concentration obtained at 66℃ was in following order; Ni (7.09% ~ 35.42%) > Cr (4.79% ~ 25.40%) > Zn (3.99% ~ 17.52%) > Cu (2.22% ~ 19.34%) > As (3.54% ~ 8.26%) > Cd (-5.08% ~ 1.08%) > Pb (-4.71% ~ -1.70%). The accuracy for certified reference materials at the digestion temperature of 80 and 85℃ was 98.7% ~ 105.8%. Therefore, digestion temperature of 80℃ ~ 85℃ is suggested to obtain reliable and reproducible data when the standard method by Korean Ministry of Environment is employed to analyze multiple heavy metal components in soil samples.

• Journal of Biosystems Engineering
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• 제35권1호
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• pp.53-63
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• 2010

The performance of two serial completely stirred tank reactors (CSTRs) for treatment of swine manure (SM) with Chinese cabbage silage (CCS) was studied. The two CSTRs of 41 liters each were connected in series and first reactor was fed swine manure with Chinese cabbage silage in 3:1 proportion by VS basis. The FOS/TAC, methane content (%) and pH were utilized as the parameters for the digester stability control. The FOS/TAC value was found to be effective indicator for instant digester condition. The stability of reactors can be obtained with the FOS/TAC value up to 1.0 with accumulation of FOS value below 10,000 mg/L. Material exchange method was effective in transferring the excess volatile fatty acids (VFA) from the first reactor to the second one and maintaining stability in both the reactors. The biogas yield and the methane yield was 0.55-0.61 and 0.41-0.42 L/g VS fed, respectively, at organic loading rate (OLR) of 2.2-2.6 g VS/L with total HRT of 32 days.

• Asian-Australasian Journal of Animal Sciences
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• 제17권6호
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• pp.820-824
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• 2004

The study was to see the effect of administration of ruminal fungi on feed intake, growth rate, rumen fermentation and nutrient digestion of calves (Tharparkar$\times$Holstein-Friesian, average age: 10 months, average body weight: 130 kg). The 6 calves in first group were fed a mixture consisted of 50% wheat straw and 50% concentrate (Maize 62%, Groundnut cake 35%, Mineral mix. 2% and Common salt 1%) along with 1 kg green oats $animal^{-1}$ $day^{-1}$ while second group calves were fed the above-mentioned diet in addition to a dose of 160 ml ($10^{6}$ CFU/ml) fungal culture $calf^{-1}$ $week^{-1}$. The average dry matter intake per day was slightly lowered in fungal fed calves yet feed conversion ratio was higher. The average daily weight gain was significantly higher (15.37%) in fungal administered group as compared to control. The nutrient digestibility was increased for crude fibre, NDF and ADF with fungal administration. Digestible energy value of straw-based diet in terms of percent TDN also increased. The pH and $NH_{3}$-N were lower whereas TVFA, total-N, TCA-N and number of zoospores were higher in rumen liquor in fungal administered group.