Judul: Identifikasi Produktivitas Induk Domba yang Digembalakan sebagai Dasar Kriteria Seleksi di Unit Pendidikan Penelitian dan Peternakan Jonggol Institut Pertanian Bogor (UP3J-IPB).
Abstrak: Local sheep is one of the animal genetic resources which is potential to be developed in supporting national meat supply. Local sheep has some superiorities such as twinning birth, early mature age and non seasonally breeding. Nevertheless, instead of these superiority, some problem still occurred as lacking of lamb survivability rate, low carcass percentage and high variances both genotype and phenotype parameters. The objectives of this study were to find the relationship between ewe age and its productivity, and ewe body measurements and its milk yield on grazing system. This study was conducted in the Jonggol Animal Science Teaching and Research Unit (JASTRU), Singasari Village, Bogor District, from June up to November 2007. As many 100 lactating ewes, on 1 to 4 years of age, were used in this study. Sheep were reared on grazing system from 9 a.m. to 4 p.m. and housed at night. The results showed that ewe age highly significant affected the body weight after lambing (p<0,01), milk yield (p<0,01), total birth weight (p<0,01) and total weaning weight (P<0,01) but did not significant for litter size. Breast circle, udder base circle, and udder height showed strong relationship in predicting 3 to 5 year ewe milk yield (p<0,01). The most productive ewes was 3 to 4 year ewes group.
Keyword: Sheep, udder size, milk yield, Weaning weight

Judul: Karakteristik Pertumbuhan Pra dan Pascasapih Domba Lokal di Unit Pendidikan dan Penelitian Peternakan Jonggol Institut Pertanian Bogor (UP3J-IPB)
Abstrak: Selection program on sheep needs some important factors like season, sex, body weight and age of dam. This research was aimed to get the characteristic of pre and post-weaning growth of local sheep in Jonggol Animal Science Teaching and Research Unit (JASTRU) IPB and selection criteria. The result can be used as a basic information on selection program to grade up the genetic properties of these sheep. This research located at JASTRU IPB, Singasari Village, sub district of Jonggol from June 2007 to May 2008 which represent two different seasons, rainy and dry. The number of sheep in the beginning of research was 154 head and in the end of research was only 33 head. The result showed that the value of Temperature Humidity Index were on slight and adequate heat. Statistic t test showed that there was a significant difference (p<0,05) between male and female birth weight in rainy season but in age of 90 and 180 day showed no significant difference. Also, birth weight between rainy and dry season was significantly different (P<0,05) and body weight on age 90 and 180 day was not significantly different. Variance analysis showed that age of dam significantly affected the male birth weight in dry season (p<0,05) and female birth weight in rainy season (p<0,05). The highest lamb body weight was owned by lamb from 2,5 to 3,0 years of dam. Pre-weaning weekly average daily gain (ADG) was higher than that of post-weaning, both on male and female, and rainy and dry season. Body weight on age 90 day can be used as a selection criteria and selection on dam can be done at age 1 to 2 years of age. Selection response of 90 day weight in dry season was higher than that of rainy season.
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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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