Judul: Evaluasi Kecukupan Nutrien Sapi Perah pada Musim yang Berbeda di Koperasi Peternak Sapi Bandung Utara (KPSBU) Lembang
Abstrak: This research was aimed at evaluating dairy cows nutritional status on milk production and quality in different rainfall. The research was done from September 2012 until June 2013 for field survey and laboratory analysis. Body weight, feed intake, nutrient contents, milk production, and milk quality have been measured and analyzed. The data were analyzed using T-test to compare the differences rainfall effect, correlation between all parameters heve been tested and regression model of milk production and quality have been made based on the correlation test. The results showed that in average dairy cows kept by small holder famer under KPSBU administration has been offered feed to fulfilled their nutrients requirement,except for mineral Ca. During early rainy, milk production, lactose, protein, and solid non fat (SNF) tends to be lower, but milk quality especially fat content of milk were higher. No satisfaction regression of milk production and quality model could be made from the parameters used which show that farmers did not consider cow performance in feeding their cattle.
Keyword: nutrient adequacy, milk quality, milk production, dairy cows

Judul: Evaluasi Kecukupan Nutrien Sapi Perah terhadap Produksi dan Kualitas Susu serta Performa yang Dihasilkan pada Peternakan Rakyat
Abstrak: Penelitian ini bertujuan untuk mengevaluasi kecukupan nutrien sapi perah laktasi serta mengetahui perbedaan produksi dan kualitas susu sapi perah di tiga lokasi peternakan rakyat terhadap intake dan penggunaan nutrien pakan serta performa sapi perah berdasarkan data intake dan penggunaan nutrien. Penelitian dilakukan mulai bulan September 2016 hingga April 2017 melaui survey lapang dan analisis laboratorium. Peubah yang diamati adalah intake pakan, intake nutrien, fermentabilitas pakan, kecernaan pakan, ME (metabolizable energy), manure score, produksi susu, komposisi susu, bobot badan, dan BCS (body conditioning score). Data dianalisis menggunakan analisis deskriptif, uji T, serta uji korelasi dan regresi untuk menduga performa ternak. Hasil penelitian menunjukkan bahwa ≤ 50% dari populasi ternak yang dapat memenuhi kecukupan nutriennya. Pendugaan performa sapi melalui analisis korelasi dan regresi intake dan penggunaan nutrien belum mendapatkan hasil yang memuaskan.
Keyword: intake nutrien, kecukupan nutrien, performa ternak, sapi perah

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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