Judul: Growth and Production Performance of Tambaqui Colossoma macropomum Given Different Commercial Feeds in Cirata Reservoir, West Java.
Abstrak: Keberhasilan budidaya intensif salah satunya ditentukan oleh kualitas pakan. Pakan berkontribusi besar dalam biaya produksi hingga mencapai 60-80%. Penelitian ini bertujuan membandingkan pengaruh lima produk pakan komersial berbeda terhadap kinerja pertumbuhan dan produksi ikan bawal (Colossoma macropomum) yang dipelihara di keramba jaring apung di Waduk Cirata. Penelitian ini menggunakan lima produk pakan komersial yaitu pakan komersial A dengan kadar protein (28,11%), pakan komersial B (28,56%), pakan komersial C (26,33%), pakan komersial D (28,11%), dan pakan komersial E (31,68%). Ikan dengan ukuran awal 10±0,1 g, dipelihara di keramba jaring apung berukuran 7 m × 7 m × 3,5 m dengan padat tebar 24 ekor/m³ selama 83 hari dengan frekuensi pemberian pakan sebanyak dua kali sehari, yaitu pukul 08.0˗009.00 dan 16.00˗17.00 secara ad satiation. Hasil penelitian menunjukkan bahwa pakan E dengan kadar protein 31,68% memberikan nilai biomassa akhir, bobot rata-rata, laju pertumbuhan harian, retensi protein, dan retensi lemak tertinggi, serta feed cost per gain dan nilai konversi pakan terendah dibandingkan lima perlakuan lainnya. Berdasarkan hasil penelitian ini dapat disimpulkan kinerja pertumbuhan dan produksi ikan bawal (Colossoma macropomum) tertinggi dan feed cost per gain terbaik diperoleh pada perlakuan pakan komersial E yang memiliki protein sebesar 31,68%., The success of intensive cultivation is determined by the quality of feed. Feed contributes greatly to production costs up to 60-80%. This study aimed to compare the effect of five different commercial feed products on the growth and production performance of tambaqui (Colossoma macropomum) reared in floating net cages in Cirata Reservoir. This study used five product commercial feeds, namely commercial feed A with protein content (28.11%), commercial feed B (28.56%), commercial feed C (26.33%), commercial feed D (28.11%), and commercial feed. E (31.68%). Fish with an initial size of 10±0.1 g were kept in floating net cages measuring 7 m × 7 m × 3.5 m with a stoking density of 24 fish/m for 83 days with the frequency of feeding twice a day, at 08.0˗ 009.00 and 16.00-17.00 with ad satiation. The results showed that feed E with a protein content of 31.68% gave the highest final biomass value, average weight, daily growth rate, protein retention, and fat retention, as well as the lowest feed cost per gain and feed conversion value compared to the other five treatments. Based on the results of this study, it can be concluded that the highest growth and production performance of tambaqui (Colossoma macropomum) and the best feed cost per gain were obtained in commercial feed treatment E which has a protein of 31.68%.
Keyword: ikan bawal, keramba jaring apung, komersial, pakan, pertumbuhan

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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