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 Performa Sapi Potong yang Diberi Pakan Silase Ransum Komplit dan Konsentrat Komersial
Abstrak: Optimal beef cattle productivity could be achieved by feeding management. This study aims to determine the performance of local breed beef cattle by given commercial concentrate and silage treatments. There were 9 animal in this study aged between 1.5-2.5 th. Parameters observed during this study were feed consumption, body weight gain, feed efficiency, feed conversion, and IOFC. The study used completely randomized design model. Data was tested by analysis of covariance (ANCOVA). The results showed no significant was effect at the consumption of dry matter intake. There were significant (P<0.05) effect of treatment on IOFC value, daily gain, feed efficiency, feed conversion. The cattle feed on concentrate produced better value for the parameters observed than feed on complete rations in the form silage.
Keyword: silage., performance of livestock, commercial concentrates, beef cattle

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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