Judul: Behavior, reproduction, and meat characteristics of white- Tail Rats (Maxomys Hellwandii)
Abstrak: This research was conducted to study behaviour, reproduction and meat characteristics, organoleptic test of white tail rats (Maxomys Hellwandii).The research was conducted in the native habitat of White tail rats in the forest of Minahasa, and in the farm outside the habitat in Tateli village of Pineleng District. The study was done for 12 months, using 190 rats consisted of 70 males and 120 females. Organoleptic test was done in the laboratory of Animal Husbandry of Sam Ratulangi University. The analysis of the meat physical and chemical properties was conducted in the Laboratory of Large Ruminant, Faculty of Animal Husbandry, and in the Laboratory of Physiology, Faculty Veterinary Medicine, IPB, Bogor. The research was conducted in four phases. The first phase was a preliminary periode to obtain information about wild white tail rats. The second phase was a study about food adaptation and behavior. The third phase was to study reproduction performance. The fourth phase was to study meat characteristic and organoleptic test. The result of the study in the original habitat showed that white tail forest rats adapted very well to environmental condition. Activity was done mostly in the evening (nocturnal) and the rats often found at wild piper, bamboo, and other fruit trees. During the day time the rats entered subterranean cave in bushes, in the roots of trees or at small stone cave. Activities done in the evening were coloning, grooming, resting, and playing. They ate most of all food types. The male rats consumed 3,89 g DM/head/day; while female rats consumed 3,34 g DM/head/day. The estrus cycle was 3 to 5 days, consisted of proestrus (12 hours), estrus (12 hours), metestrus (18-24 hours), and diestrus (45-54 hours). The carcass percentage were 59.17% for male rats, and 54.24% for female. Based on chemical properties, the meat of white tail rats had water and fat content lower than that of other domestic livestocks. The meat of white tail rats also had higher content of omega 3, 6 and 9 fatty acids. The content of free water in the meat of white tail rats was low as compared to that of beef, lamb, and napu. White tail rats meat can be accepted by people in the Regency of Minahasa and Manado City. This meat is prefer to dogs meat, pork, and beef.
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Judul: Perbedaan Ukuran Screen dan Die Terhadap Kualitas Fisik Pelet dan Performa Tikus Putih (Rattus norvegicus)
Abstrak: The purpose of study was to obtain pellets feed for White Rats (Rattus norvegicus) on growth phase form which has the best physical quality of pellets and rats performance. The research was carried out using factorial randomized complete design 2 x 2. The first factor was screen size (3 mm and 5 mm) and the second factor was die size (4 mm and 16 mm). The treatments were P1 (screen 3 mm die 4 mm), P2 (screen 3 mm die 16 mm), P3 (screen 5 mm die 4 mm), P4 (screen 5 mm die 16 mm). The study on physical quality of pellets was performed in four replications for each treatment. Parameters measured were durability, bulk density, density compacted and true density. The study on in vivo trial on rats was conducted in five replications for each treatment. Parameters measured were body weight gain, consumption, dry matter digestibility, and organic matter digestibility. Data were analyzed using Analysis of variance and Duncan multiple range test. The result showed that there was an interaction effect between screen and die size on durability (P<0.01) and true density (P<0.01) of pellets, and body weight gain (P<0.05) and consumption (P<0.01) of the rats. It was concluded that pellet P1 has the best physical quality and P2 showed the best performance of rats.
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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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