Judul: Kecernaan dan Fermentabilitas Rumen secara In Vitro dengan Penambahan Konsorsium Bakteri Selulolitik
Abstrak: Penelitian ini bertujuan menguji pengaruh pemberian konsorsium bakteri selulolitik yang berasal dari feses hewan herbivora endemik Indonesia terhadap karakteristik fermentatif dan kecernaannya dalam rumen secara in vitro. Penelitian ini menggunakan rancangan acak lengkap (RAL) dengan 4 perlakuan dan 5 ulangan. Perlakuan terdiri atas P0 (40% pakan konsentrat komersial, 30% rumput gajah, dan 30% daun sawit) sebagai kontrol, P1 (P0 + 105 cfu konsorsium bakteri selulolitik per gram sampel), P2 (P0 + 106 cfu konsorsium bakteri selulolitik per gram sampel), dan P3 (P0 + 107 cfu konsorsium bakteri selulolitik per gram sampel). Peubah yang diukur meliputi nilai pH, NH3, VFA total, koefisien cerna bahan kering (KcBK), koefisien cerna bahan organik (KcBO), dan koefisien cerna serat kasar (KcSK). Hasil penelitian menunjukkan bahwa pemberian konsorsium bakteri selulolitik memberi efek yang signifikan pada perlakuan P3 terhadap peningkatan nilai VFA total, KcBK, dan KcSK, namun tidak signifikan terhadap nilai pH, NH3, dan KcBO. Simpulan dari penelitian ini adalah pemberian konsorsium bakteri selulolitik dalam ransum dapat bekerja secara optimal terhadap fermentabilitas dan kecernaan rumen.
Keyword: cellulolytic bacteria, digestibility, in vitro, rumen fermentability

Judul: Characteristics of Rumen Fermentation In Vitro with Supplementation of Cellulolytic Probiotic: Quantitative Literature Review
Abstrak: Probiotik selulolitik merupakan feed additive yang mengandung bakteri selulolitik sebagai penghasil enzim selulase yang digunakan untuk menghidrolisis selulosa kompleks dari pakan hijauan menjadi glukosa, yang selanjutnya diubah menjadi Volatile Fatty Acid (VFA). Penelitian ini dilakukan untuk mengkaji penggunaan probiotik selulolitik secara in vitro terhadap karakteristik fermentasi di rumen dengan menganalisis data dari berbagai studi terkait menggunakan model matematis analisis regresi linear dan kuadratik. Sebanyak 19 studi diperoleh 119 data digunakan dengan variabel yang meliputi nilai pH, produksi gas total, produksi gas metana, konsentrasi amonia, konsentrasi total VFA, proporsi asetat, propionat, dan butirat, rasio asetat:propionat, kecernaan bahan kering dan organik, kecernaan Neutral Detergent Fiber (NDF), populasi bakteri, serta populasi protozoa. Hasil analisis regresi menunjukkan bahwa pemberian probiotik selulolitik sangat nyata meningkatkan (P≤0,01) produksi gas total, konsentrasi amonia, konsentrasi total VFA, proporsi asetat, serta kecernaan bahan kering dan organik. Pemberian probiotik selulolitik juga nyata meningkatkan (P≤0,05) proporsi asam butirat, rasio asetat:propionat, kecernaan NDF, dan populasi bakteri, namun tidak berpengaruh terhadap nilai pH dan populasi protozoa. Selain itu, pemberian probiotik selulolitik sangat nyata menurunkan (P≤0,01) proporsi propionat. Dapat disimpulkan bahwa pemberian probiotik selulolitik secara in vitro dengan taraf penggunaan mulai dari 106 -1012 cfu ml-1 cairan rumen dapat memodifikasi fermentasi di rumen.
Keyword: cellulolytic probiotic, cellulose, rumen

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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