Judul: Utilisasi Silase Jerami Jagung dengan Suplementasi Kulit Matoa terhadap Penurunan Produksi Gas Metan secara In Vitro
Abstrak: Penelitian ini bertujuan untuk menganalisis pengaruh jerami jagung dengan suplementasi kulit matoa terhadap fermentabilitas dan kecernaan rumen secara in vitro. Penelitian menggunakan rancangan acak lengkap (RAL) dengan 4 perlakuan dan 4 ulangan. Perlakuan meliputi P0 = 1 kg jerami jagung; P1 = 1 kg jerami jagung + 20% kulit matoa; P2 = 1 kg jerami jagung + 30% kulit matoa; P3 = 1 kg jerami jagung + 40% kulit matoa. Parameter yang diamati yaitu analisis proksimat, gas total, gas metana, pH rumen, volatile fatty acid (VFA), NH3, sintesis protein mikrobial (SPM), kecernaan bahan kering (KcBK), kecernaan bahan organik (KcBO), total bakteri, dan populasi protozoa. Data dianalisis menggunakan analysis of variance (ANOVA) dan diuji lanjut dengan Uji Duncan menggunakan program SPSS 25. Perlakuan tidak berpengaruh nyata terhadap pH rumen, kadar NH3, SPM, KcBK, dan KcBO. Namun, berpengaruh nyata pada total produksi gas total, penurunan gas metan, dan konsentrasi VFA. Silase jerami jagung dengan suplementasi kulit matoa efektif menurunkan gas metan, tetapi tidak mempengaruhi fermentabilitas dan kecernaan rumen., This study aimed to analyze the effect of corn straw silage with matoa peel supplementation on fermentability and rumen digestibility in vitro. This study used a completely randomized design (CRD) with 4 treatments and 4 replications. The treatments consisted of P0 = 1 kg corn straw; P1 = 1 kg corn straw + 20% matoa peel; P2 = 1 kg corn straw + 30% matoa peel; P3 = 1 kg corn straw + 40% matoa peel. Parameters observed were proximate analysis, gas production, methane gas, rumen pH, volatile fatty acid (VFA), NH3, microbial protein synthesis (MPS), dry matter digestibility (DMD), organic matter digestibility (OMD), total bacteria, and protozoa population. Data were analyzed using analysis of variance (ANOVA) and further tested with Duncan's test using the SPSS 25 program. The treatment had no significant effect on rumen pH, NH3 levels, MPS, DMD, and OMD. However, the treatment had a significant effect on total gas production, methane gas reduction, and VFA concentration. Corn straw silage with matoa peel reduced methane gas but it did not affect on rumen fermentability and digestibility.
Keyword: fermentabilitas, in vitro, jerami jagung, kulit matoa, Metan

Judul: Evaluation of The Use of Gynura procumbens Leaves in Total Mixed Ratio Silage on Fermentability and Methane Gas Production
Abstrak: Perbaikan pakan khususnya untuk ternak ruminansia harus memperhatikan aspek lingkungan karena adanya gas metan yang dihasilkan dari proses fermentasi oleh mikroba rumen. Sambung nyawa (Gynura procumbens) memiliki potensi untuk dikembangkan sebagai hijauan pakan ternak yang mampu menekan emisi gas metan. Namun, belum banyak ditemukan informasi terkait pengolahannya. Penelitian ini bertujuan mengevaluasi penggunaan sambung nyawa dalam silase ransum komplit terhadap fermentabilitas rumen dan produksi gas metan. Penelitian ini menggunakan rumput gajah dan sambung nyawa sebagai hijauan dan beberapa bahan konsentrat untuk pembuatan silase ransum komplit. Formulasi ransum ditujukan untuk sapi perah laktasi dengan bobot badan (BB) 450 kg, produksi susu 10 kg 4% FCM. Rancangan percobaan yang digunakan adalah rancangan acak lengkap (RAL) dengan 4 perlakuan dan masing-masing perlakuan dilakukan ulangan sebanyak 5 kali. Parameter yang diukur adalah kualitas fisik silase ransum komplit (warna, aroma, tekstur, penyusutan), pH silase, pH rumen, NH3, volatile fatty acid (VFA), sintesis protein mikroba (SPM), kecernaan bahan kering (KcBK), kecernaan bahan organik (KcBO), total bakteri, total protozoa, produksi gas total, dan gas metan. Data yang diperoleh dari hasil penelitian dianalisis dan diolah menggunakan sidik ragam (ANOVA) dengan software SPSS Statistic 23 dan Microsoft Excel. Hasil penelitian menunjukkan bahwa perlakuan penambahan sambung nyawa memberikan pengaruh nyata (p<0,05) terhadap pH silase, SPM, total protozoa, total bakteri, produksi gas, dan gas metan. Perlakuan Gynura procumbens sambung nyawa tidak memberikan pengaruh nyata (p>0,05) terhadap penyusutan silase ransum komplit, pH rumen, NH3, volatile fatty acid (VFA), kecernaan bahan kering, dan kecernaan bahan organik. Simpulan penelitian ini adalah penambahan sambung nyawa hingga taraf 15% dapat diberikan tanpa mempengaruhi kualitas fisik silase, kecernaan bahan kering dan organik, pH silase, pH rumen, penyusutan silase ransum komplit, VFA, dan NH3 masih dalam kisaran normal, meningkatkan SPM, total bakteri, dan total produksi gas, serta mampu menurunkan populasi protozoa dan produksi gas metan., Feed improvement, especially for ruminants, must pay attention to environmental aspects because of the methane gas produced from the fermentation process by rumen microbes. Gynura procumbens has the potential to be developed as forage that can reduce methane emissions. However, not much information has been found regarding its processing. The research was conducted to evaluate the use of hibiscus in complete ration silage on rumen fermentability and methane gas production. The research used elephant grass and Gynura procumbens as forage and several concentrate ingredients for making total mixed ratio silage. The ration formulation was intended for lactating dairy cows with body weight (BW) 450 kg, milk production 10 kg 4% FCM. The experimental design used was a completely randomized design (CRD) with 4 treatments and each treatment was replicated 5 times. Parameters measured were the physical quality of total mixed ratio silage (color, aroma, texture, shrinkage), total mixed ratio silage pH, rumen pH, NH3, volatile fatty acid (VFA), microbial protein synthesis (MPS), dry matter digestibility, organic matter digestibility, total bacteria, total protozoa, total gas production, and methane gas. Data obtained from the results of the study were analyzed and processed using variance analysis (ANOVA) with SPSS Statistic 23 software and Microsoft Excel. The results showed that the treatment of the addition of Gynura procumbens gave a
Keyword: fermentabilty, Gynura procumbens, methane

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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