Judul: The Addition of Selenoprotein through Feed on the Growth of Tilapia Juvenile (Oreochromis niloticus)
Abstrak: Penelitian ini bertujuan mengevaluasi penambahan selenoprotein melalui pakan terhadap pertumbuhan benih ikan nila (Oreochromis niloticus). Terdapat tujuh perlakuan berbeda, yaitu K (pakan tanpa penambahan selenoprotein), A, B, C, D, E, dan F (pakan dengan penambahan selenoprotein berturut-turut sebesar 0,3 mg kgˉ¹, 0,6 mg kgˉ¹, 1,2 mg kgˉ¹, 2,4 mg kgˉ¹, 4,8 mg kgˉ¹, dan 9,6 mg kgˉ¹). Penelitian ini menggunakan rancangan acak lengkap dengan tujuh perlakuan dan tiga ulangan. Benih ikan nila berbobot 3±0,14 g dipelihara selama 42 hari pada akuarium berukuran 90 x 40 x 45 cm3 dengan padat tebar 15 ekor/akuarium. Ikan diberi pakan tiga kali sehari secara at satiation. Hasil penelitian menunjukkan penambahan selenoprotein dibawah 9,6 mg kgˉ¹ dapat meningkatkan kinerja pertumbuhan benih ikan nila dengan dosis terbaik 0,3 mg kgˉ¹ pakan yang menghasilkan pertumbuhan dua kali lebih besar., This study aimed to evaluate the addition of selenoprotein through feed on the growth of tilapia juvenile (Oreochromis niloticus). There were seven different treatments, namely K (feed without selenoprotein addition), A, B, C, D, E, and F (feed with selenoprotein addition respectively 0,3 mg kgˉ¹, 0,6 mg kgˉ¹, 1,2 mg kgˉ¹, 2,4 mg kgˉ¹, 4,8 mg kgˉ¹, and 9,6 mg kgˉ¹). This study used a completely randomized design with seven treatments and three replications. Tilapia juvenile weighing 3±0,14 g were reared for 42 days in an aquarium measuring 90 x 40 x 45 cm3 with a stocking density of 15 fish/aquarium. Fish were fed three times a day on an at satiation method. The results of this study showed that the addition of selenoprotein below 9,6 mg kgˉ¹ could increase the growth performance of tilapia juvenile with the best dose of 0,3 mg kgˉ¹ of feed which results in two times greater growth.
Keyword: growth, selenoprotein, tilapia

Judul: Suplementation of Selenium Yeast into the Feed on the Growth of Tilapia Oreochromis niloticus Juvenile
Abstrak: Selenium yeast merupakan salah satu bentuk selenium organik sehingga lebih mudah diserap oleh tubuh dan memiliki tingkat toksisitas lebih rendah daripada selenium anorganik. Penelitian ini bertujuan menganalisis penambahan berbagai dosis selenium yeast pada pakan terhadap pertumbuhan benih ikan nila Oreochromis niloticus. Penelitian menggunakan rancangan acak lengkap dengan tiga ulangan pada enam perlakuan, yaitu penambahan selenium yeast dengan dosis 0, 0,5, 1, 2, 4, dan 9 mg kg-1 pakan. Ikan nila bobot 3,15±0,04 g ekor-1 dipelihara dalam akuarium berukuran 90 × 40 × 45 cm3 dengan padat tebar 15 ekor akuarium-1. Ikan dipelihara selama 42 hari dan diberi pakan sebanyak tiga kali sehari secara at satiation. Hasil penelitian ini menunjukkan bahwa penambahan selenium yeast pada pakan memengaruhi biomassa akhir, bobot akhir, laju pertumbuhan harian (LPH), jumlah konsumsi pakan, dan feed conversion ratio (FCR) (p<0,05) namun tidak memengaruhi tingkat kelangsungan hidup (TKH) dan rasio efisiensi protein (REP) (p>0,05). Nilai LPH benih ikan nila meningkat seiring dengan meningkatnya dosis penambahan Se-yeast hingga dosis 1 mg kg-1 pakan. Penambahan Se-yeast dosis 1, 2, 4, dan 9 mg kg-1 pakan tidak berbeda secara signifikan pada nilai LPH, TKH, FCR, dan REP. Berdasarkan hasil penelitian ini, dapat disimpulkan bahwa penambahan selenium yeast dosis 1 mg kg-1 pakan dapat meningkatkan pertumbuhan benih ikan nila. Selain itu, penambahan selenium yeast hingga dosis 9 mg kg-1 pakan masih dapat ditolerir dan belum bersifat toksik untuk benih ikan nila., Selenium yeast is one of the forms of organic selenium, therefore more easily to be absorbed by the body and has lower toxicity than inorganic forms. This study aimed to analyze the different levels of selenium yeast supplementation into the feed on the growth of tilapia Oreochromis niloticus juvenile. The study used a completely randomized design with three replications in six treatments, namely the different levels of selenium yeast supplementation, 0, 0.5, 1, 2, 4, and 9 mg kg-1 feed. Fifteen tilapia with weigh of 3.15±0.04 g fish-1 were distributed in 90 × 40 × 45 cm3 aquarium. Fish were reared for 42 days and fed three times a day at satiation. The results showed that selenium yeast supplementation into the feed effected final biomass, final weight, daily growth rate (DGR), amount of feed consumption, and feed conversion ratio (FCR) (p<0.05), but did not effect survival rate (SR) and protein efficiency ratio (PER) (p>0.05). DGR of tilapia juvenile increased with increasing level of selenium yeast supplementation up to 1 mg kg-1 feed. Selenium yeast supplementation of 1, 2, 4, and 9 mg kg-1 feed were not significantly different on DGR, SR, FCR, and PER. In conclusion, selenium yeast supplementation of 1 mg kg-1 feed could increase the growth of tilapia juvenile. Moreover, selenium yeast supplementation up to 9 mg kg-1 feed was still tolerable and not toxic yet for tilapia juvenile.
Keyword: selenium yeast, feed, growth, tilapia

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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