Judul: Evaluation of Production Performance of Three Grand Parent  Stock Strains of 24-Week-Old Broiler Breeds in Indonesia
Abstrak: Ketersediaan ayam ras pedaging level Final Stock (FS) yang cukup di Indonesia tidak bisa lepas dari keberhasilan sejumlah perusahaan pembibitan ayam ras didalam melakukan pemeliharaan indukan level Parent Stock (PS) dan Grand Parent Stock (GPS). Secara teknis pemeliharaan GPS terbagi menjadi 2 (dua) periode yaitu periode rearing umur 1-24 minggu dan periode produksi umur 25 – 65 minggu. Tujuan utama pemeliharaan pada periode rearing adalah untuk menghasilkan ayam dengan berat ideal, keseragaman (uniformity) yang tinggi, kondisi dan kematangan seksual yang cukup sehingga dapat menghasilkan telur tetas yang baik pada saat memasuki periode produksi. Selain itu keberhasilan pemeliharaan pada periode rearing menjadi hal penting yang harus diperhatikan oleh setiap perusahaan pembibit dalam mempersiapkan GPS menuju periode produksi. Secara teknis di lapangan setiap perusahaan pembibitan berupaya untuk mencapai peforma produksi sesuai dengan standar yang telah ditetapkan oleh perusahaan principal sesuai dengan strain-nya masing-masing. Terdapat beberapa parameter yang harus diperhatikan oleh perusahaan pembibitan dalam pemeliharaan periode rearing antara lain bobot badan, konsumsi pakan, deplesi, keseragaman dan sex rasio. Capaian performa produksi masing-masing perusahaan pembibitan tentunya akan dipengaruhi oleh faktor internal dan eksternal, walaupun faktor cuaca dan kondisi mikro saat ini mampu diatasi dengan adanya teknologi closed house sehingga sangat dimungkinkan capaian performa produksi dari masing-masing perusahaan pembibit akan mengalami perbedaan. Atas kondisi tersebut perlu dilakukan evaluasi terhadap capaian performa produksi pada akhir periode rearing umur 24 minggu baik pada GPS ayam ras pedaging betina (D-Line) maupun jantan (C-Line) dari masing-masing strain yang dipelihara di perusahaan dibandingkan terhadap standar performa produksi yang telah ditetapkan prinsipal. Evaluasi performa produksi GPS umur 24 minggu ini belum pernah dilakukan sebelumnya sehingga hasil penelitian dapat memberikan informasi capaian performa produksi GPS ayam ras pedaging dari masing-masing strain yang berkembang di Indonesia. Ruang lingkup penelitian ini mencakup data performa produksi GPS ayam ras pedaging D-Line dan C-Line pada periode akhir rearing umur 24 minggu dengan strain S1, S2 dan S3 berasal dari 46 flock yang tersebar di 8 perusahaan pembibitan ayam ras di Indonesia pada wilayah Jawa Timur, Jawa Tengah, Jawa Barat, Lampung, Sumatera Selatan, Sumatera Utara dan Kalimantan Barat dari tahun 2019 sampai dengan tahun 2021. Penelitian evaluasi performa produksi GPS ayam ras pedaging ini terbagi dalam tiga bahasan yaitu perbandingan performa antar strain, perbandingan antar perusahaan/wilayah dan perbandingan performa aktual dibandingkan dengan standar prinsipal masing-masing. Hasil uji perbandingan capaian performa produksi GPS ayam ras pedaging antar strain S2 dan S3 sebagian besar menunjukkan adanya perbedaan. Pada GPS ayam ras pedaging D-Line perbedaan terjadi pada performa konsumsi pakan, tingkat kematian, dan keseragaman, sedangkan pada capaian bobot badan menunjukkan capaian yang relatif sama. Pada GPS ayam ras pedaging C-Line menunjukkan adanya capaian yang relatif sama pada performa bobot badan, kematian, dan sex rasio, sementara untuk capaian performa produksi untuk konsumsi pakan dan keseragaman menunjukkan adanya perbedaan capaian antar strain. Perbandingan capaian performa aktual dibandingan dengan standar prinsipal, sebagian besar strain menunjukkan adanya perbedaan dengan standar yang telah ditetapkan prinsipal. Untuk strain S1 pada GPS ayam ras pedaging D-Line dan C-Line menunjukkan adanya perbredaan capaian dibandingkan dengan standar yang ditetapkan prinsipal, terkecuali untuk sex rasio capaian relatif sama dengan standar yang ditetapkan
Keyword: performa, produktivitas, strain, GPS, performa, produktivitas, strain, GPS

Judul: FLOCK PERFORMANCE OF FOUR STRAINS OF BROILER GRAND PARENT STOCK IN INDONESIA
Abstrak: Indonesia annually imports broiler breeds classified as Grand Parent Stock (GPS) to meet the needs of the parent stock and produce broiler (Final Stock). The import of GPS since 1970 until now has not been fully researched to find out the performance of GPS maintenance results from breeding farm companies. The maintenance performance of imported GPS needs to be studied and evaluated carefully to describe the progress and productivity achievements of the breeding farm of all strains in Indonesia. This study aims to determine the performance of four strain broiler Grand Parent Stock (GPS) rearing flocks in Indonesia compared to the production (laying) period for young, medium, and old flock groups, which currently has never been conducted with similar studies. The research material used secondary data from the Directorate General of Livestock and Animal Health, Ministry of Agriculture, in the form of recordings of GPS maintenance of purebred chickens in Indonesia, including four types of strains, namely S1.1 strain, S1.2 strain, S1.3 strain and S1.4 strain spread across various farm units and flock. The total number of flocks studied was 94 flocks from 12 breeding farm companies. The analytical method used is one way ANOVA analysis to compare strains as a variable performance factor covering three GPS strains having one type of fast hair growth in common, namely Fast Feathering (FF), namely strains S1.1, S1.2 and S1.4. One way ANOVA analysis was also carried out to compare the performance of the S.1.3 strain which has a Slow Feathering (SF) type of hair growth in terms of four provincial locations. The variables studied included Hen Day Production (HDP), primary product, egg weight and hatching weight. The results for the S1.3 strain in terms of locations in four different provinces showed an average hen day production in the young age group of 78.98 ± 4.69%. the medium group was 63.95 ± 4.02% and the old group was 43.70 ± 2.59%. The average performance of the primary product strain S1.3 in the young group was 15.35 ± 1.47, in the medium group it was 39.34 ± 3.69 and in the old group it was 58.77 ± 2.78. The performance of the hatching egg weight of strain S1.3 in the young group was an average of 58.59 ± 1.33 g, in the medium group it was 64.95 ± 1.78 g and in the old group it was 67.43 ± 1.67 g. The average hatching weight performance of strain S1.3 in the young group was 38.26 ± 0.87 g, in the medium group it was 42.06 ± 1.29 g and in the old group it was 42.43 ± 1.16 g. The results of the one way ANOVA test showed that all variables did not show differences in performance at the four provincial locations. Comparison of performance between strains showed that the average HDP was significantly different and the highest HDP was strain S1.1 in the young age group with an average of 78.05 ± 4.88%, in the medium age group with an average of 51.55 ± 3.27% and in the middle age group with an average of
Keyword: performa flock, strain grand parent stock

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.
Keyword: