Judul: Variasi Kandungan Nutrien dalam Pakan dan Prediksi Kecukupannya pada Ransum Sapi Perah di Indonesia
Abstrak: Feed is the greatest cost component in dairy production. Availability and quality of feed dictate the productivity of the animal. This study was done to evaluate the nutrient content of dairy feed variation in Indonesia. Nutrition content of feed samples analized according to the proximate analisis conducted from 2008-2011 in Feed Quality Control Agency, Directorate General of Livestock Services, Ministry of Agriculture were used in this study. Data were evaluated according to descriptive analyis. The result showed that nutrient content of dairy feed had high variability. Nutrient content of some feed was higher or lower than that of Indonesia National Standard. Proportion of concentrate which their nutrients content were not in the range of SNI, were 81.63 %, 92.20% and 67.65% for ash, Ca and P respectively. It was suggested, that the policy in animal feed were important to establish inorder to inforce the available regulation in feed to minimize the potential loss experienced by the farmers
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Judul: Penyediaan Pakan dan Kecernaan Nutrien Berdasarkan Produksi Susu dan Skala Tingkat Kepemilikan Ternak Sapi Perah Berbeda
Abstrak: Penelitian ini bertujuan untuk mengetahui dan mengevaluasi kecukupan nutrien dan utilitas nutrien pada produksi susu sapi perah berdasarkan skala tingkat kepemilikan peternak. Penelitian ini dilaksanakan pada bulan September 2016 hingga April 2017 yang mencakup survei lapang dan analisis laboratorium. Parameter yang diukur pada penelitian ini adalah pemberian pakan, intake nutrien, manure score, produksi susu, komposisi susu, bobot badan, dan BCS (Body Conditioning Score). Analisis data yang digunakan adalah analisis deskriptif untuk mengetahui dan membandingkan performa ternak dan produksi susu berdasarkan skala tingkat kepemilikan. Hasil dari penelitian ini menunjukkan bahwa performa yang dimiliki oleh sapi berdasarkan produksi susu sebagian besar masih belum ideal dengan bobot badan antara 394.54±37.26 kg-424.38±43.33 kg, BCS berkisar antara 2.51±0.27-2.60±0.26, dan manure score berkisar antara 2.94±0.44-3.07±0.81. Persentase ternak yang sudah memenuhi kebutuhan nutrien berdasarkan produksi susu sebesar 48.2%, 64.8%, dan 61.4%. Tingkat produksi susu yang relatif tinggi terdapat pada tingkat kepemilikan ternak 1-3 ekor, yaitu 18.59 l e-1 hari-1 dan ternak yang telah memenuhi kebutuhan nutrien berdasarkan produksi susu terdapat pada skala tingkat kepemilikan ternak 1-3 ekor. Data yang dihasilkan menunjukkan bahwa skala tingkat kepemilikan yang relatif memiliki produksi susu tinggi dan kebutuhan nutrien yang mencukupi adalah 1-3 ekor. Oleh karena itu, perlu adanya perhatian lebih untuk peternak rakyat yang memiliki ternak sapi perah lebih dari 3 ekor.
Keyword: produksi susu, sapi perah, skala tingkat kepemilikan

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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