Judul: Kinerja Pertumbuhan Ikan Bawal Air Tawar (Colossoma macropomum) yang Diberi Makan Timol
Abstrak: Ikan bawal air tawar (Colossoma macropomum) merupakan komoditas ikan air tawar yang dibudidaya di Indonesia. Penelitian ini bertujuan mengevaluasi pengaruh pemberian thymol dengan dosis yang berbeda pada pakan terhadap kinerja petumbuhan ikan bawal. Penelitian menggunakan empat perlakuan dengan penambahan dosis thymol sebesar 0,0, 0,2, 0,4, dan 0,6 g/kg pakan. Setiap perlakuan diulang sebanyak empat kali. Benih ikan bawal bobol 8,22±0,01 g dipelihara dalam akuarium berukuran 90x45x45 cm dengan tinggi air 30 cm. Setiap akuarium diisikan sebanyak 15 ekor ikan bawal untuk kemudian dipelihara selama 70 hari. Hasil penelitian menunjukkan bahwa pemberian pakan ditambah thymol sebanyak 0,6 g/kg berpengaruh nyata (p<0,05) terhadap perlakuan lainnya dan dapat meningkatkan kinerja pertumbuhan ikan seperti nilai total biomassa akhir, bobot rata-rata akhir, rasio efisiensi protein dan laju pertumbuhan spesifik serta dapat meningkatkan status antioksidan ikan bawal., Tambaqui (Colossoma macropomum) is a freshwater fish commodity cultivated in Indonesia. This study aims to evaluate the effect of giving thymol at different doses in feed on the growth performance of tambaqui. The study used four treatments with additional thymol doses of 0.0, 0.2, 0.4, and 0.6 g/kg feed. Each treatment was repeated four times. Tambaqui fry weighing 8.22±0.01 g were maintained in an aquarium measuring 90x45x45 cm with a water height of 30 cm. Each aquarium was filled with 15 tambaqui to be kept for 70 days. The results of the study showed that feeding added with thymol at 0.6 g/kg had a significant effect (p<0.05) on other treatments and could improve fish growth performance, such as final total biomass value, final average weight, protein efficiency ratio, and specific growth rate, and could increase the antioxidant status of tambaqui.
Keyword: Growth, tambaqui, thymol

Judul: Growth Performance of Tambaqui (Colossoma macropomum) Given Different Commercial Feeds.
Abstrak: Pemberian pakan yang berkualitas menjadi salah satu upaya untuk meningkatkan produksi ikan karena pertumbuhan ikan dipengaruhi oleh pakan. Biaya pakan mencapai 60% dari total biaya produksi. Penelitian ini bertujuan membandingkan pengaruh empat produk pakan komersial berbeda terhadap kinerja pertumbuhan ikan bawal air tawar (Colossoma macropomum) yang dipelihara pada akuarium. Penelitian ini menggunakan empat produk pakan komersial dengan protein pakan yang cenderung sama, yaitu pakan komersial A (27,84%), pakan komersial B (27,11%), pakan komersial C (27,01%), pakan komersial D (28,48%). Ikan bawal yang digunakan memiliki bobot rata-rata 11,32±0,01 g ekor-1. Sebanyak 15 ekor ikan dipelihara dalam akuarium berukuran 90×40×45 cm selama 60 hari dengan pemberian pakan tiga kali sehari yaitu pada pukul 08.00, 13.00, dan 18.00 WIB secara ad satiation. Kinerja pertumbuhan ikan bawal yang diberi pakan komersial berbeda menunjukkan hasil berbeda nyata (p<0,05). Perlakuan D memiliki nilai biomassa akhir (Bt), average daily growth (ADG), laju pertumbuhan spesifik (LPS), rasio efisiensi protein (REP), dan retensi protein (RP) tertinggi di antara perlakuan lainnya. Perlakuan pakan D juga memiliki nilai Rasio Konversi Pakan (RKP) dan Feed Cost per Gain (FCG) terendah di antara perlakuan lainnya. Berdasarkan hasil penelitian ini dapat disimpulkan pemberian pakan dengan kadar protein yang relatif sama menunjukan kinerja pertumbuhan yang berbeda. Kinerja pertumbuhan ikan bawal air tawar (C. macropomum) terbaik diperoleh pada perlakuan pakan komersial D yang memiliki protein 28,48%., Providing quality feed is one of the efforts to increase fish production because fish growth is influenced by feed. Feed costs account for 60% of the total production costs. This study aims to compare the effect of four different commercial feed products on the growth performance of tambaqui (Colossoma macropomum) cultured in aquariums. This study used four commercial feed products with feed protein that tended to be the same, namely commercial feed A (27,84%), commercial feed B (27,11%), commercial feed C (27,01%), commercial feed D (28,48%). The tambaqui used had an average weight of 11,32 ± 0,01 g-1. A total of 15 fish were kept in an aquarium measuring 90×40×45 cm for 60 days with feeding three times a day at 08.00, 13.00 and 18.00 WIB with ad satiation. The growth performance of tambaqui fed different commercial feeds showed significantly different results (p<0.05). The D treatment had the highest final biomass (Bt), average daily growth (ADG), specific growth rate (LPS), protein efficiency ratio (REP), and protein retention (RP) were the highest among other treatments. The D treatment also has the lowest Feed Conversion Ratio (RKP) and Feed Cost per Gain (FCG) value among the other treatments. Based on the results of this study it can be concluded that feeding with relatively the same protein content shows different growth performance. The growth performance of tambaqui (C. macropomum) was best obtained in the treatment of commercial D feed which had 28.48% protein.
Keyword: tambaqui, commercial, feed, growth

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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