• Asian-Australasian Journal of Animal Sciences
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• 제13권7호
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• pp.922-928
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• 2000

The effects of animal species and supplements on rumen fluid characteristics, plasma urea-N (PUN) concentration, plasma urea-N pool size, urea-N degradation in the gut and urea-N net flux (urea-N synthesis rate) were studied in goats and sheep, with some minor differences detected. The animals were fed either chopped rice straw ad libitum+200 g soybean meal (SBM), or chopped rice straw ad libitum+190 g soybean meal+300 g sago meal (SBM+SM) for 14 days. The supplements were isonitrogenous (80 g crude protein/animal/d). [$^{14}C$]-urea was used as the marker for urea metabolism studies. Two animals from each species were fed either supplement in a cross-over design in two periods. The results showed that rumen pH was significantly (p<0.001) lower in animals fed SBM+SM than those fed SBM supplement. The ammonia concentrations of rumen fluid were significantly (p<0.01) higher in sheep (382.9 mg N/L) than goats (363.1 mg N/L) when fed SBM supplement but lower (282.5 mg N/L) than that of goats (311.0 mg N/L) when fed SBM+SM supplement. Total VFA concentrations were significantly (p<0.05) higher in animals fed SBM+SM supplement than those fed SBM supplement. Goats had significantly (p<0.01) higher molar proportions of acetate (79.1, 77.7%, respectively) than sheep (75.8, 74.0%, respectively) in both supplements. The molar proportion of acetate was significantly (p<0.05) higher, while that of butyrate lower in animals fed SBM supplement than those fed SBM+SM supplement. In animals fed SBM supplement, the molar proportion of propionate was significantly (p<0.01) higher in sheep (18.0%) than in goats (15.6%), but in animals fed SBM+SM, the molar proportion of butyrate was significantly (p<0.01) higher (9.6%) in sheep than in goats (7.2%). Plasma urea-N concentration, plasma urea-N pool size, urea-N degradation in the gut, urea-N net flux and the fraction of urea-C from the blood entering the rumen were not significantly different between goats and sheep fed either supplement. However, PUN concentration was significantly (p<0.05) lower in animals fed SBM+SM supplement (average of 13.8 mg N/100 ml) than in those fed SBM supplement (average of 16.5 mg N/100 ml). The urea net flux was significantly (p<0.05) higher in goats (average of 14.5 g N/d) than sheep (average of 12.9 g N/d), and animals fed SBM supplement showed higher (average of 14.9 g N/d) urea net flux than animals fed SBM+SM supplement (average of 12.9 g N/d). A significant (p<0.05) positive correlation was observed between urea-N net flux and urea-N degradation; urea-N net flux and pool size; urea-N net flux and urea excretion in the urine; and PUN and rumen ammonia in goats. While in sheep, significant (p<0.05) positive correlation was observed between urea-N net flux and urea excretion in the urine; and PUN and rumen ammonia.

• Journal of Applied Biological Chemistry
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• 제57권4호
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• pp.313-320
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• 2014

Black liquor (BL) is a by-product of rice straw pulping process. It is a low costs raw material for production value-adding proteins and enzymes, which has been paid more and more attention to reduce its environmental pollution. Mixed cultures of micelial fungi, Trichoderma reesei Northern Regional Research Laboratory (NRRL)11236, Trichoderma reesei NRRL 6165 and Aspergillus niger strains NRC 5A, NRC 7A, and NRC 9A were evaluated for their ability to produce xylanase using crude hemicellulose (CHC) prepared from BL and peat moss as an inert support under solid state fermentation (SSF). The most potent strains, A. niger NRC 9A (818.26 U/g CHC) and T. reesei NRRL 6165 ($100.9{\pm}57.14$ U/g CHC), were used in a mixed culture to enhance xylanase production by co-culturing under SSF. In the mixed culture, xylanase production ($1070.52{\pm}12.57$ U/g CHC) was nearly1.3 and 10.6-fold increases over the activities attained in their monocultures, A. niger NRC 9A and T. reesei NRRL 6165, respectively. Optimization of the culture parameters of the mixed culture SSF process, concentration of ammonium sulfate and corn steep liquor, CHC/peat moss ratio, inoculum size and ratios of the two strains, initial pH value, initial moisture content and incubation time, exhibited a significant increase ($2414.98{\pm}84.02$ U/g CHC) in xylanase production than before optimization.

• 한국농공학회논문집
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• 제55권5호
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• pp.1-7
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• 2013

The objective of this research was to experimentally test the effect of tillage methods on the reduction of runoff, non-point source (NPS) pollution load, sediment and discharge under a rainfall simulation. We used the runoff plots of $5m{\times}30m$ ($L{\times}W$) in size. Experimental treatments were conventional tillage (CT), CT-rice straw bundle (CT-RSB) and two no-till (NT) plots; slope of 3 % or 8 % ; and rainfall intensity of 30 mm/hr. The rainfall simulation was conducted to three times. The time to initial runoff from NT plots was less than that from CT plots regardless of the slope and it was delayed about 65~90 % compared to that of CT plot. And sediment discharge of 8 % slope reduced to 55 % compared to CT plot. But the sediment discharge was not occurred at 3 % slope. The NT and CT-RSB methods have a great possibility of reducing runoff and NPS pollution loads. Runoff rate of NT plots was significantly lower than those of CT plot. The average NPS pollution loads of the NT plots and CT-RSB plot reduced about 55~80 % and 2.1~40 % compared to those of the CT plots, respectively. It was also shown that runoff and NPS pollution loads reduction by NT method could be very significant and contribute to improve the water quality of streams in agricultural regions. It was concluded that the use of NT method on agricultural fields could reduce soil erosion and muddy runoff significantly and help improve the water quality and aquatic ecosystem.

• Journal of Biosystems Engineering
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• 제42권3호
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• pp.136-146
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• 2017

Purpose: This paper presents an appropriate wrapping method by analyzing the pressure distribution applied to a bale surface, along with the change in pressure according to an increase in the number of film layers in rice straw bales, which account for 74% of the total bulky feed supply in Korea. Methods: A model with the shape of an actual bale was fabricated to analyze the distribution of surface pressure in bale wrapping, and the pressure was measured. Experiments were conducted to analyze the pressure using eight different layer numbers (2, 4, 6, 8 10, 12, 14, and 16 layers) at five wrapping speeds (27, 29, 31, 33, and 35 rpm). Results: The maximum pressure applied to a circular bale by the film occurred at the center of the end of the bale, whereas the minimum pressure occurred at the center of the bale side. An extreme value ratio between the minimum and maximum pressures was distributed as 8.5-56.6%, which was improved with an increase in rotation speed. The an uneven pressure distribution occurred because the number of film overlaps was 8.24-times greater at the center of the bale's end than at the center of the ba le side. At a level 5 rotation speed, the minimum pressure was $P_{LV5-M1}=0.0625{\sigma}^2+36.173{\sigma}-36.753$ ($R^2=0.9845$) at $M_1$, and the maximum pressure was $P_{LV5-M6}=5.5552{\sigma}^2+41.05{\sigma}-39.071$ at $M_2$, revealing a correlation of $R^2=0.9983$. Conclusions: To replace four layers with six layers, 2-4 layers were added only to the side of the bale, and the minimum pressure at $M_1$ was then improved from that at four layers to that at six layers, and the amount of film consumed for 4-6 layers was reduced by 84.6%.

• 농업과학연구
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• 제37권2호
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• pp.309-314
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• 2010

Bale is an operation of collecting livestock feed materials from field crop residue, and mechanization demand on the operation has been increased. Bailers imported from foreign countries such as Japan and European countries have been used, but those models showed improper performance in Korean situations. In recent years, a steel-roller type round baler attachable to medium size tractors(40 to 60 HP) for effective bale operation in Korea was developed. This study was conducted to evaluate field performance of the baler. For proper baling operation, engine speed was greater than 1,800rpm, average traction force and PTO torque were about 4kN and in a range of 380-671Nm, and maximum values were about 7kN and 3,000Nm, respectively. Performance evaluation tests for sudan grass, rice straw, and blue barley showed that field capacity was 0.59ha/h for blue barley and 0.99ha/h for sudan grass and rice straw. Bale weight, diameter, width, and bulk density were in ranges of 176.1~418.4kg, 1.07~1.12m, 1.02~1.04m, and 175.3~454.1kg/$m^3$. Noise sound level during the baling operation was 4dB greater than idle operation condition, which was considered to be ignorant.

• 한국초지조사료학회지
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• 제28권2호
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• pp.107-118
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• 2008

본 실험은 NDF 및 ADF 함량이 높은 버섯폐배지(버섯잔사)에 대한 볏짚 대체 가능성을 채식 행동 관점에서 검토할 목적으로 실시하였으며, 시험사료인 농후사료+볏짚(Control: 5.32kg+자유채식), 농후사료+버섯폐배지+볏짚(T1 : 5.32kg+0.82kg+자유채식) 및 농후사료+버섯폐배지+ 볏짚 (T2 : 5.32 kg+1.64 kg+자유채식)를 급여하여 채식 행동 조사를 하였다. 공시가축은 평균체중 357.0+2.9kg인 한우 18두를 이용하였으며, 사료급여에 있어서는 농후사료와 버섯페배지는 1일 2회로 반량씩 급여하였으며 볏짚은 자유채식토록 하였다. 볏짚 채식량은 Control구가 2.66kg으로서 가장 높게, T2구가 2.03 kg으로 가장 낮게 나타난 반면, 총채식량 및 NDF 채식량은 T2 > T1 > Control구 순으로 높게 나타났다. 채식시간은 Control구가 289.3분, T2구가 290.5로 비슷했고 T1구가 236.0분으로 가장 적었다(p<0.05). 반추시간에 있어서는 버섯폐배지 첨가량을 0%(0.0kg), 15%(0.82kg) 및 30%(1.64kg)로 증가 시켜줌에 따라 반추시간은 451.0분에서 359.5분으로 직선적으로 감소하였다(p<0.05). 이는 버섯폐배지의 사료입자 크기가 매우 작았던 것에 기인된 것으로 생각된다. 1일 저작시간, 식괴수, 저작회수와 식괴당 저작수 및 사료가치지수는 볏짚을 급여한 대조구에서 모두 높게 나타났다(p<0.05). 그러나 식괴당 반추시간은 T2(69.4분)에서, 분 당 식괴수는 T1구(1.07번)에서 높게 나타났다(p<0.05). 채식율, 반추효율 및 저작효율성에 있어서는 버섯폐배지 첨가 급여구(T1, T2)가 무첨가 급여구(Control)에 비하여 높게 나타났으며, 이는 높은 채식량과 버섯폐배지의 작은 입자도가 관여한 것으로 생각된다. 군 행동은 모든 구(Control, T1 및 T2)에서 농후사료 급여시에 통일된 행동을 보였고, 반추 및 휴식에 있어서 군 행동은 처리 간 큰 차이가 없는 것으로 나타났다. 이상의 결과 육성우 배합사료에 버섯폐배지 15% 및 30%를 첨가 급여함으로서 반추시간, 식괴수, 저작수 및 FVI치는 다소 낮은 결과치를 보였으나, 채식행동에 큰 문제가 될 정도는 아니며, 오히려 채식율, 반추효율 및 저작효율에 있어서 무첨가구에 비하여 첨가구가 높았던 점을 감안 할 때 한우 육성우 조사료원으로서 대체 가능성을 기대할 수 있다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.337-340
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• 2001

The production of xylanase from Aspergillus niger mutant in SSF was optimized by' using statistical experimental designs. An inoculum size of $5{\times}10^5$ spores/g. initial moisture content of 65 %. cultivation time of 5 days and 10 times concentration of basal medium containing 50 times concentration of CSL were optimum for xylanase production ‘ Under the optimized conditions. the activity and productivity of xytanase obtained after 5 days of fermentation were 5.071 IU/gram of rice straw and 14.790 IU/l.h. respectively.

• Applied Biological Chemistry
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• 제27권
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• pp.18-28
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• 1984

In order to improve feed values of Korean agricultural by-products, various treatments including physical, chemical, physicochemical and fermentation were suggested in th is review article. Physical treatments such as chopping, grinding and pelleting reduce partiole size of agricultural by-products, and increase passage rate from the rumen, thus may increase voluntary feed intake and weight gain. Digestibility and voluntary feed intake of straw, rice hull and sawdust, also, may be increased by chemical treatment using sodium hydroxide or ammonia. Especially, because nitrogen content of by-products increase and toxic problem is not posed by ammonia treatment, it's practical usage is recommended in Korea. Silage or fermentation treatment using principles of microbial fermentation may improve palatability of low quality by-products. As mentioned above, it is concluded that various treatments suggested are desirable and improve feed value but may raise several problems. Unfortunately, because cost for installation and products is great and processing work is complicate, farmers are not using well these processing methods until now. Therefore, in order to increase the practical usage at farm level, it is thought that many research works be achieved for efficient process which have simple operation and low installation cost.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2002년도 춘계학술발표대회 발표논문초록집
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• pp.3-3
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• 2002

본 연구는 개의 동결정액제조 시 동결보호 희석액 내에 첨가되는 당의 종류와 조합이 동결융해 후 정자의 생존율 및 운동성에 미치는 영향과 정자동결 시 straw size, 예비동결 시 액체질소표면으로부터 straw까지의 거리 및 융해온도가 생존율에 미치는 영향에 대하여 조사하고자 실시하였다. 포유류의 경우 부생식선의 정낭선에서 분비되는 정장내에는 정자의 체외사출 후 정자의 영양물질인 fructose 가 분비되는데, 동결정액제조 시 회석액내에 첨가되는 당 성분은 fructose 및 glucose를 일반적으로 사용하고 있다. (중략)

• The Plant Pathology Journal
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• 제20권2호
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• pp.103-105
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• 2004

A destructive stem rot of strawberry (Fragaria x ananassa cv. Akihime) sporadically occurred in farmers' fields in Daegok-myon, Jinju city, Gyeongnam province in Korea. The infected plants showed stem and crown rot, with occasional blighting of the whole plant. White mycelia appeared on stems of infected clones and sclerotia formed on the old lesions near soil surface. The fungus formed white colony on PDA and showed maximum mycelial growth and sclerotial formation at $30^{\circ}C$. The fungus usually have many narrow hyphal strands, 2.6-10.0 $\mu\textrm{m}$ in width, in the aerial mycelium. Typical clamp connections were formed on the mycelium. Sclerotia were spherical and 1.0-2.4 mm in size. The fungus was repeatedly isolated from infected tissues and identified as Sclerotium rolfsii. Its patho-genicity was confirmed when inoculated onto straw-berry. This is the first report on the stem rot of strawberry caused by S. rolfsii in Korea.