Judul: Kecukupan Nutrien Makro pada Sapi Pejantan di Balai Inseminasi Buatan Lembang Jawa Barat
Abstrak: The shortage of replacement stock is a limiting factor in development of dairy and beef industry in Indonesia. Availability and performance of the replacement stock is influenced by feed availability and feeding management. The objective of this study was to evaluate the nutrient sufficiency in Bulls reared in the Institute for Artificial Insemination (BIB), Lembang - West Java. Information on feeding management, physiological condition and semen production recorded from 75 bulls was evaluated. The breed of bulls were Frisian Holstein (FH), Limousine, Simmental, Angus, Brangus, Brahman, and Ongole. They varied in their age and body weight. Feed offered were elephant grass, sugarcane top, hay, tauge and concentrate. Total feed offered was based on the body weight. Result indicated that the makro nutrients in the rations offered to the bulls was inacxess. Bulls produce high quality semen, therefore the bull has obtained the sufficient ammount of nutrient for reproduktif and milk production. Health problem of bulls was assciated with the inbalance nutrient intake.
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Judul: Evaluasi Kecukupan Nutrisi Sapi Perah di Kawasan Usaha Peternakan Cibungbulang Bogor, Jawa Barat
Abstrak: The study is aimed to evaluate nutritional status of cows and their relation to animal performance at two different seasons (drought and rainy). The study was conducted in two phases. First phase was drought season data collecting for 3 months and the second phase was rainy season data collecting. The sample collected was examined in Dairy Nutrition and PAU laboratories IPB (March – June 2013). Variable was measured including the type and amount of feeds and nutrients offered, milk production and quality, body condition score. The collected data was tabulated and analyzed using descriptive statistic. Comparison between nutrients offered and standard requirement was analyzed using T-test. T-test have also been used to compare nutritional status of animal in rainy and drought seasons. The result showed that farmers in KUNAK have offered sufficient amounts of nutriens for their cows exept for Ca, when drought season came, deficiency of P was also occured. Milk yield tent to decrease during drought season but milk fat content increase during drought season but milk fat content increased. It is concluded that imbalance ration is one of the cause for low average milk production in KUNAK.
Keyword: nutrient adequacy, milk quality, milk production, dairy cows

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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