Judul: Peran Tepung Darah sebagai Fe Organik pada Pakan dalam Meningkatkan Imunitas Ikan Kerapu Bebek Cromileptes altivelis
Abstrak: The problem that was dealt in the grouper culture was the stress condition caused by the decrease of water quality (environmental stress). If this happen, amount of the pathogen bacteria in grouper will increase so will impact in decline of appetite and immunity response. The further problem was the limitations of the waste fish as main food the grouper. As the replacement, normally was used pelet. But, evidently the production of the fish-meal as the main raw material the compiler pelet that was expensive and continued the production reduction in the period for the last 10 years enabled to look for the alternative to the use of the fish-meal as the food raw material. Blood meal was one of the raw materials of the fish-meal of replacement food. Apart from having the content of high protein (89-92 %), blood meal also had the iron content that was high reached 2769 mg/kg. The iron content that was high could it was hoped increase the response of fish immunity if stress happening. Furthermore, the height of protein could it was hoped encourage the growth of the fish. The research was carried out in the month May-October 2009 took place in the Station Field Center of the Study of Knowledge of Fisheries Institut Pertanian Bogor (PSIK IPB) Ancol, North Jakarta. This research used the random plan complete (RAL) with five treatments and respectively the treatment used three tests. The amount of blood meal that was used was 0%, 9%, 12%, and 15%. Commercial food was used as the standard. The beginning weight in general the fish that was tested was 11,6 0.23 g. The maintenance was carried out for 40 days density 10 tails/litre and was given food 3 times a day in struck 07,00, 12,00, and 17,00 WIB in an at adsatiation (until the fish was full). After 40 maintenance days, the fish was taken totalling 3 tails to be carried out by the analysis proksimat and to count retention of protein and his fat. Further, was carried out by the test about towards the bacterial infection Vibrio algynolitycus to know the level of resistance of the fish body. Observation of the health of the fish was carried out through the taking of the sample of fish blood on the day 0, that is before the infection and on the 3rd day, on the 5th day, and on the 9th day after infection. For 40 treatment days with the use of blood meal to the fish, was received by results that were not different real towards the parameter of the amount of consumption of food, retention of protein, retention of fat, the growth rate of the daily, and food
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Judul: Suplementasi Mineral Seng Zn sebagai Penyeimbang Penggunaan Tepung Darah dalam Pakan Terhadap Kinerja Pertumbuhan dan Ketahanan Tubuh Ikan Kerapu Bebek Cromileptes altivelis
Abstrak: Tepung darah selain dapat dijadikan sebagai sumber protein dapat juga dijadikan sebagai sumber zat besi (Fe) organik. Tepung darah merupakan bahan baku yang mengandung Fe dalam konsentrasi yang sangat tinggi mencapai 2769 mg/kg (NRC 1993 dalam Fox 2004). Kandungan Fe yang sangat tinggi ini dapat menyebabkan penurunan kemampuan penyerapan Zn (Linder 1992). Zn merupakan mikro mineral yang essensial bagi ikan yang memiliki peranan penting dalam proses metabolisme tubuh ikan. Apabila konsentrasi Zn dalam tubuh ikan kurang dari batas normal dapat menyebabkan munculnya gejala defisiensi antara lain pertumbuhan yang lambat, erosi sisik, dan katarak pada mata yang apabila dibiarkan akan menyebabkan kerugian bagi para pembudidaya. Selain berperan dalam proses metabolisme, Zn juga memiliki peranan penting dalam kinerja sistem imun (Calder 2002). Penelitian ini dilakukan untuk mengevaluasi pengaruh suplementasi Zn dengan level berbeda dalam pakan yang mengandung tepung darah sebagai sumber Fe organik terhadap kinerja pertumbuhan dan ketahanan tubuh ikan kerapu bebek Cromileptes altivelis pada saat sebelum dan sesudah perlakuan stress.
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Judul: Bifurkasi Hopf pada Model Siklus Bisnis Kaldor Kalecki tanpa dan dengan Waktu Tunda
Abstrak: Business cycle model is one of dynamical system models in economic. One of the business cycles model is Kaldor-Kalecki model. Kaldor-Kalecki business cycle model that is written in delayed defferential equations, is a business cycle model that involves gross product and capital stock of a company. In this paper Kaldor-Kalecki business cycle model is analyzed using both nondelay and delay in time of capital stock. By Taylor expansion for the time delayed model, an analysis of stability around the fixed points has been done. Furthermore, by using Hopf bifurcation theorem, it can be shown that there exists periodic orbits and limit cycle. In the nondelayed model, changing the parameter of goods market could lead to the occurrence of Hopf bifurcation and the existence of limit cycle. Similarly, for the delayed model, it has been shown that changing the time delay parameter may result in the occurrence of Hopf bifurcation and limit cycle.
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