Judul: Komparasi Kecernaan Ransum dengan Penambahan Hay dan Silase Daun Rami pada Ternak Kambing Jawarandu secara In Vivo
Abstrak: The study was aimed to compare in vivo digestibility of ramie leaves in the form of hay and silage in jawarandu goat ration. The experiment was done using ewe jawarandu goats weighted 27 ± 4,68 kg from September to December 2010 at the Field Laboratory of Dairy Cattle Nutrition, Faculty of Animal Science, Bogor Agricultural University. Randomized block design was used in this experiment. Three types of ration (R1= Control ration consisted of 50% grass + 50% concentrate; R2 consisted of 50% grass + 40% concentrate + 10% ramie leaf silage, and R3 consisted of 50% grass + 40 + 10% concentrate % hay ramie leaf) were used as treatments. Each treatment was repeated thrice. Ration and nutrients offered, ration and nutrients left over, total faecal and its composition were measured for consumptions and digestibilites calculations. The data obtained were analyzed using analysis of variance (ANOVA) and continued with Duncan's multiple range tests. The results showed that the digestibility of crude protein (DCP) in R1 (68.6%) was higher than R3 (54.90%) and R2 (40.51%) but there were no significant different effect of R1, R2, and R3 on digestibilities of dry matter (DMD), extract ether (DEE), crude fibre (DCF), and nitrogen free extract (DNFE) of the rations. Substitution of 10% concentrate by ramie either in hay or silage forms did not affect digestibility of ration and nutritions except protein digestibility. Subtitution of concentrat by ramie leave in form of hay produced a better digestibility compare to silage. The addition of 10% ramie leaf shaped silage or hay in the ration concentrate jawarandu goats could be done and could produce a good ration digestibility, especially digestibility of ether extract. However, the addition of 10% ramie leaf shaped silage or hay has not been able to replace the protein source of feed materials making up the concentrate control ration (soybean meal and coconut meal) in terms of crude protein digestibility. The provision of ramie in the form of hay produced higher digestibility DCP than ramie in the form of silage.
Keyword: 

Judul: The evaluation of nutrient quality of ramie leaves silage and hay in complete mixed ration for Etawah-Crossbreed goat using in vitro technique
Abstrak: A research have been conducted to evaluate the effect of ramie leaves silage and hay in Etawah Crossbreed (PE) goat complete mixed ration (CMR) on nutrient content, fermentability, and digestibility by in vitro. There were seven CMR dietary treatments i.e. P0 (control ration) = 50% napier grass + 50% concentrate, P1 = 30% napier grass + 20% ramie leaves silage + 50% concentrate, P2 = 20% napier grass + 30% ramie leaves silage + 50% concentrate, P3 = 10% napier grass + 40% ramie leaves silage + 50% concentrate, P4 = 30% napier grass + 20% ramie leaves hay + 50% concentrate, P5 = 20% napier grass + 30% ramie leaves hay + 50% concentrate, and P6 = 10% napier grass + 40% hay + 50% concentrate. Both ramie leaves silage and hay increased the CMR digestibility and nutrient content, except the crude fiber. Control ration had a higher crude fiber than silage and hay. The CMR which contain ramie leaves silage (40%) had higher nutrient digestibilities compared to the other rations. Rations which were added with ramie leaves silage (P1 – P3) had a higher VFA concentration compared to the other rations. Ammonia concentration of rations added with preserved ramie leaves were lower than control, however ammonia concentration in all treatments were in optimal range. Acetate proportion was higher in CMR which contain ramie leaves hay than CMR which contain silage and the nutrients digestibilities were lower. Adding ramie leaves silage in rations resulted higher propionate and butyrate proportion than control and rations which added with ramie leaves hay. Either silage or hay ramie leaves can be used up to 40% as Napier grass substitute in the PE CMR.
Keyword: 

Judul: Bifurkasi lokal pada titik tetap non-hiperbolik
Abstrak: Bifurkasi menggambarkan perubahan pada struktur orbit di sekitar titik tetap. Titik tetap dibagi menjadi dua yaitu titik tetap hiperbolik dan titik tetap non-hiperbolik. Titik tetap non-hiperbolik terjadi jika ada nilai eigen dengan bagian real sama dengan nol. Kestabilan dari titik tetap dapat diketahui dari nilai eigen yang diperoleh dari pelinearan medan vektor. Pada bifurkasi satu-dimensi ditemukan kasus-kasus untuk bifurkasi saddle-node, bifurkasi transcritical dan bifurkasi pitchfork. Bifurkasi saddle-node terjadi jika satu sisi dari nilai parameter tidak terdapat titik tetap dan pada sisi lain terdapat dua titik tetap, dimana yang satu stabil dan yang lainnya tak-stabil. Bifurkasi transcritical terjadi jika terdapat pertukaran kestabilan, yaitu dari titik tetap stabil menjadi titik tetap tak-stabil dan sebaliknya. Sedangkan bifurkasi pitchfork dibagi menjadi dua, yaitu: bifurkasi pitchfork supercritical dan bifurkasi pitchfork subcritical. Bifurkasi pitchfork supercritical terjadi jika satu titik tetap stabil berubah menjadi dua titik tetap stabil dan satu titik tetap tak-stabil, dan bifurkasi pitchfork subcritical terjadi jika satu titik tetap stabil dan dua titik tetap tak-stabil berubah menjadi satu titik tetap tak-stabil. Bifurkasi Hopf (bifurkasi dua-dimensi) terjadi jika terdapat orbit periodik pada struktur orbitnya yang berupa lingkaran dengan jari-jari konstan. Ada atau tidaknya orbit periodik dapat diketahui setelah sistem ditransformasikan ke dalam koordinat polar. Orbit periodik ini dapat bersifat stabil maupun tak-stabil. Model periklanan (advertising) Feichtinger merupakan salah satu contoh penerapan bifurkasi Hopf Model ini menghasilkan satu titik tetap dan orbit periodik yang bersifat stabil.
Keyword: