Judul: The Influence of Participated Cows in Determining Candidate Bulls Based on Daughter Cow Milk Production in Jawa Barat
Abstrak: Uji zuriat (Progeny test) salah satu upaya untuk meningkatkan kualitas genetik ternak sapi perah. Uji zuriat menghasilkan anak betina (Daughter Cow/DC) yang memiliki produksi susu tinggi tidak hanya ditentukan oleh calon pejantan unggul (Candidate Bull/CB) tetapi juga dari kualitas induk betinanya (Participated Cow/PC). Performa Participated Cow (PC) yang digunakan dalam kegiatan uji zuriat sangat beragam, dengan pemilihan Participated Cow (PC) yang tepat menjadi salah satu metode yang efektif untuk meningkatkan kualitas genetik dan produksi susu ternak sapi perah. Tujuan penelitian untuk menganalisis keunggulan kualitas Participated Cow (PC) dan keunggulan Candidate Bull (CB) berdasarkan produksi susu Daughter Cow (DC) khususnya di daerah Jawa Barat. Penelitian menggunakan data sekunder uji zuriat periode III pada tahun 2017-2020. Parameter Participated Cow (PC) meliputi angka kelahiran, sex ratio, periode laktasi, dan produksi susu. Parameter Candidate Bull (CB) meliputi volume, dosis semen, kualitas, dan konsentrasi sperma. Parameter Daughter Cow (DC) hanya meliputi produksi susu. Analisa data secara deskriptif melalui program excel. Hasil penelitian menunjukkan bahwa kualitas pada Participated Cow (PC) di Jawa Barat menunjukkan angka kelahiran 52,45%, periode laktasi 1, 2, dan 3 masingmasing sebesar 34,02%, 46,08%, dan 19,90%. Sex ratio 44,75% berjenis kelamin betina dan 52,25% berjenis kelamin jantan. Produksi susu Participated Cow (PC) sebesar 14,25 kg/ekor/hari dan produksi susu Daughter Cow (DC) sebesar 17,75 kg/ekor/hari. Semen pada Candidate Bull (CB) di BIB Lembang memiliki kualitas yang baik dengan nilai rataan konsentrasi spermatozoa sebesar 1160,82±244,48 jt/ml, gerakan massa sebesar 2,01±0,07, motilitas individu sebesar 70,86±0,06%, pH sebesar 6,58±0,16, volume semen sebesar 6,31±1,80 mL dan produksi semen beku: 270,50±86,25, straw.. Disimpulkan bahwa produksi susu Daughter Cow (DC) lebih tinggi dari produksi susu Participated Cow (PC) akan tetapi belum signifikan. Keragaman kualitas PC merupakan salah satu faktor yang dapat mempengaruhi produksi susu Daughter Cow (DC). Standar operasional yang kurang tepat membuat pemilihan PC sebagai indukan masih belum optimalsehingga mempengaruhi hasil produksi susu DC. Candidate Bull (CB) uji zuriat periode III di BIB Lembang menunjukkan hasil normal sesuai dengan standar semen beku dan layak digunakan sebagai replacement pejantan unggul dalam pengembangan sapi perah di Indonesia.
Keyword: Sapi Perah, karakteristik semen, produksi susu, Uji Zuriat, progeny test, friesian holstein, semen characteristics, milk production

Judul: Kualitas Participated Cow untuk Menentukan Calon Pejantan Unggul berdasarkan Produksi Susu Daughter Cow di Jawa Timur
Abstrak: Optimal milk production of Daughter Cows (DC) is not only determined by the quality of Candidate Bulls (CB), but also by the Participated Cows (PC). The diversity of PC quality is one of the factors that can affect the milk production of DC. Improper operational standards can lead to the selection of less-than-optimal PC as dams. This study aims to analyze the superiority of PC’s quality based on DC milk production and evaluate the superiority of CB. This study uses secondary data from the third period of progeny test in 2017-2020. The PC parameters observed included birth rate, sex ratio, lactation period, and milk production. The CB parameters include volume, semen dosage, sperm quality, and concentration. The DC parameter only includes milk production. The data were analyzed using descriptive analysis through the excel program. The results showed that the quality of semen on the CB at NAIC Singosari has a good quality an average pH value of 6,46±0,17, an average semen volume of 7,15±1,87 mL, an average mass movement of 2,26±0,43, an average individual motility of 73,45±0,06%, an average concentration of 1012,25±287,29 million/mL, and frozen semen production of 295,57±123,03 straws. The quality of PC shows a high birth rate of 97,22% with lactation period 1, 2, and 3 respectively at 48.27%, 40,79%, and 10,94%. The sex ratio produced is 53% female and 47% male. The milk production of PC is 13,77 kg/head/day and the milk production of DC is 14,24 kg/head/day. It was concluded, that the milk production of DC is higher than the milk production of PC. The seven CBs based on DC milk production from the highest order are Aris, Flate, Flanggo, Glens, Doming, Folegan, and Shoty. Candidate bulls in the third period of progeny test are suitable to be launched as proven bull and their frozen semen is suitable for distribution for the development of the national dairy cattle.
Keyword: friesian holstein, milk production, progeny test, semen characteristics

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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