Judul: Efektivitas Isolat Bakteri Rumen Kerbau Pencerna Serat dalam Fermentasi Hijauan Leguminosa dan Pemanfaatan Urea in vitro
Abstrak: Ruminants have ability to digest fiber component of feed due to the presence of cellulolitic bacteria in their rumen that secrete cellulase. Other bacteria have capability to digest protein by secreting protease and utilize non protein nitrogen. Fiber-digesting bacteria isolated from rumen of buffalo have not been confirmed in their ability to digest protein rich feed and utilize protein. This study aimed to evaluate the ability of fiber-digesting bacteria isolates in digesting leguminous herbage, degrading protein and utilizing non protein nitrogen. The first study was to compare the fermentability and coeficient digestibility of Calliandra callotyrsus, Leucaena leucocephala, Indigofera sp. and Gliricidia sepium by using bacteria in fresh rumen fluid and fiber-digesting bacteria isolates. The second study aimed to evaluate the ability of buffalo rumen bacterial isolates in the use of urea. Corn and cassava waste were used as carbohydrate sources with addition of urea as non protein nitrogen at level of 3%, 4,5%, and 6%. The first study showed that source of bacteria had no different effect on VFA concentration, and the coeficient digestibility of dry and organic matter of the herbage. The NH3 levels in the treatment of bacterial isolates was higher than that of fresh rumen fluid (P <0.05). The buffalo rumen bacterial isolates have the ability to degrade proteins and also showed that Indigofera sp., and Gliricidia sepium protein more susceptible to degradation than other legumes. The levels of NH3 in fermentaion media of feed added urea to 6% was in normal level. It was concluded that fiber-digesting rumen bacteria isolates were able to digest leguminous herbage and utilize the protein component of legume and capable of utilizing urea up to 6% in starchy feed.
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Judul: Potency of bacteria isolates from rumen buffaloes for enhancing forage digestion and performance of frisian holstein calves
Abstrak: Rumen bacteria plays an important role in digesting feed. The respective bacteria are adapted to low quality forage from agricultural by-product, especially those originated from rumen fluid of buffaloes. Study of innoculating buffalo rumen bacteria as probiotic into the rumen of Holstein Frisian calves have not been investigated so far. The aims of the present study were: (1) to isolate and characterize bacteria from buffalo, and (2) to evaluate the quality of isolates for enhancing forage digestion in Frisian Holstein calves. The study consisted of three studies: (1) Isolation, characterization, and genetic identification of buffalo rumen bacteria, (2) in vitro evaluation on various sources of forage and concentrates, and (3) in vivo evaluation into calves with different inoculation period. Design of the first study was based on a completely randomized factorial design with two factors: the type of bacteria and types of forage source, in which the diversity of bacteria were analyzed using NTSys 2.10 program. The second study was also based on a completely randomized factorial design, where the factors were various bacterial sources and feed types. The third study was consisted of two experiments, both were using completely randomized designs. The first experiment was to determine the effectiveness of bacteria consortium innoculation into Frisian Holstein calves with three calves received the respective inoculation (treatment group) and four calves without any inoculation (control group). The second experiment was todetermine the potency of bacteria consortium innoculation into Frisian Holstein calves during preweaning with three calves as treatment group and three calves as control. The results showed that: (1) buffalo rumen bacteria can grow well on forage substrates in which 14 isolates of bacteria possessed a high adaptability to fiber (high CMCase activity); these isolates could be clustered into six types which have similarity ≥ 51%. (2) Dry matter digestibility of concentrate were almost the same between the consortium of bacteria and buffalo rumen fluid. (3) buffalo rumen bacteria is a potential probiotic and could effectively be innoculated since preweaning period. (4) Inoculation of bacteria consortium increased feed intake and cobalt uptake on weaning period. (5) Inoculation of bacteria consortium did not cause any negative effects on ADG, physiological status and rumen fermentability.
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Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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