Judul: Responses of productivity and milk quality on suplementation of mineral soap, organic minerals and roasted soybeans in ruminant diets
Abstrak: Milk production and quality are limited by feed quality either macronutrient or micronutrient. The objectives of this study were to protect essential fatty acids from degradation of rumen microbes, increase ruminant productivity, increase CLA and omega-3 content of milk. The experiment was divided into 3 parts. The first experiment was supplement production. The second experiment was evaluation of the productivity response of sheep to supplements. Thirty two Garut sheep (initial body weight of 22.38±3.56 kg) were assigned into a randomized complete block design with 8 treaments. Body weight was used as a block (4 blocks). Eight rations evaluated in this trial were FO: basal diet + fish oil, CO: basal diet + corn oil, CaFO: basal diet + calcium soap of fish oil, CaCO: basal diet + calcium soap of corn oil, ZnFO: basal diet + zinc soap of fish oil, ZnCO: basal diet + zinc soap of corn oil, RS: basal diet + roasted soybeans, MM: basal diet + mineral mix. The experimental diets were offered for 8 weeks. The third experiment was designed to measure milk yield and quality responses of dairy cattle to supplement. Twenty lactating Frisian Holstein cows (initial weight of 361.4 ± 40.39 kg) were assigned into a randomized complete block design with 5 treatments and 4 block. The treatments were B: basal diet, RS: B + roasted soybeans, MM: RS + mineral mix (organic-Zn, Cu, Cr, Se), CaCO: MM + calcium soap of corn oil, CaFO: MM + calcium soap of fish oil. The experimental diets were offered for 2 weeks preliminary and 9 weeks of observations period.
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Judul: Konsentrasi mineral makro (Ca, P, Mg, dan S) dalam susu pada sapi yang diberi suplemen biomineral dienkapsulasi.
Abstrak: Lower productivity of dairy cow is caused by lack of grass availability especially in dry season, low concentrate quality and nutrient deficiency. The purpose of this experiment was to study the concentration of macro minerals (Ca, P, Mg, and S) in milk of Fries Holland dairy cows to the addition of encapsulated biomineral supplement in feed. The biominerals was prepared from rumen liquor. This experiment used a randomized block design, with 4 treatments and 4 groups as replications. Treatments consisted of R1 (control), R2 (R1 + 1.5 % biomineral without protection), R3 (R1 + 1.5% encapsulated biomineral) and R4 (R2 + 1.5% mineral mix). The experiment was conducted for 62 days with the adaptation periods for 2 weeks. Variables observed were dry matter intake, mineral consumptions and mineral concentrations (Ca, P, Mg, and S) in milk. The data were analyzed using Analysis of Variance, and differences among treatments were further examined with Contrast Orthogonal Test. The results showed that treatments did not significantly affect feed consumption, mineral intake and mineral concentrations in milk. However, the biomineral supplements can still be used as supplement in dairy ration.
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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.
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