Judul: Sifat Karkas dan Daging Sapi Silangan Lokal yang Diberi Ransum Silase dan Konsentrat
Abstrak: The objective of the study was to evaluate carcass and meat traits of local crossbred cattle fed on silage and concentrate based rations. There were 10 animals alloted to 2 level feeding treatments; 5 animals given P1 ration (60% silage + 40% grass) and the other 5 animals given P2 ration (60% concentrate + 40% grass). Data of carcass and meat traits were analyzed using analysis of covarian (ANCOVA) corrected by the weight cut. The results showed that the carcass weight and percentage of local crossbred cattle fed on concentrate ration was higher than silage ration (P<0.05). Carcass weight and percentage of carcass beef fed on ration concentrate is 179.148 ± 1.617 kg and 54.941 ± 0.523% while the carcass weight and percentage of local crossbred cattle fed on silage ration is 172.851 ± 1.617 kg and 54.941 ± 0.523%. However, fat thickness, ribeye area, and meat traits were not significantly affected by such treatment. It was concluded that the local crossbred cattle given silage based ration produced lower carcass weight and percentage but similar fat thickness, ribeye area, and meat quality compared to that given concentrate based ration.
Keyword: silage, meat traits, concentrate, carcass traits

Judul: Perbandingan Potongan Komersial Karkas pada Sapi Silangan Lokal Jantan yang Diberi Pakan Silase dan Konsentrat
Abstrak: Penelitian ini bertujuan untuk membandingkan sebaran daging, lemak, dan tulang pada setiap potongan komersial antara sapi silangan lokal yang diberi perlakuan pakan silase dan konsentrat. Total 10 ekor sapi silangan lokal jantan dengan umur I0-I2 dan rataan bobot awal 252.5 kg. Perlakuan pakan yang digunakan adalah konsentrat dan silase dengan masing-masing 5 ekor ternak untuk setiap perlakuan. Data karakteristik karkas, bobot potongan komersial, dan persentase potongan komersial dianalisis dengan menggunakan Analysis of Covariance (ANCOVA). Data karakteristik karkas dikoreksi terhadap bobot awal. Data bobot dan persentase potongan komersial dikoreksi terhadap bobot potong. Rataan bobot potong sapi yang diberi konsentrat dan silase berturut-turut 332.94 kg dan 319.06 kg. Sapi yang diberi pakan konsentrat menghasilkan persentase karkas dan bobot daging yang nyata lebih tinggi dibanding pakan silase (P<0.05). Rataan persentase karkas sapi yang diberi pakan konsentrat dan silase berturut-turut adalah 54.99% dan 52.90%, sedangkan rataan total bobot daging sapi yang diberi pakan konsentrat dan silase berturut-turut adalah 65.74 kg dan 58.81 kg. Hasil penelitian menunjukkan data potongan komersial tidak berbeda nyata kecuali bobot lemak bagian topside dan brisket sapi dengan pakan konsentrat nyata lebih tinggi (P<0.05) dibandingkan dengan perlakuan pakan silase, serta persentase lemak bagian topside sapi dengan perlakuan konsentrat nyata lebih tinggi dari silase (P<0.05).
Keyword: Characteristic carcass, Concentrate, Commercial cut, Silage, Animal science, Analysis of coveriance, Ancova, Feed treatment

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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