Judul: Growth Performance of Tilapia Oreochromis sp. Fed with Citral Addition by Coating Method
Abstrak: Citral merupakan senyawa bioaktif feed additive yang dapat meningkatkan pemanfaatan karbohidrat. Feed additive yang ditambahkan pada pakan dengan metode coating diduga akan berbeda dengan yang dicampurkan pada saat pembuatan pakan karena adanya risiko leaching. Penelitian ini bertujuan mengevaluasi pengaruh penambahan citral pada pakan secara coating dengan dosis yang berbeda terhadap kinerja pertumbuhan dan antioksidan ikan nila Oreochromis sp.. Penelitian terdiri atas empat perlakuan yaitu pakan tanpa tambahan citral (C0) sebagai kontrol negatif, pakan dengan dosis citral 100 mg kg-1 menggunakan metode repelleting (CR100) sebagai kontrol positif, serta pakan dengan dosis citral berbeda menggunakan metode coating yaitu 150 mg kg-1 (CC150), 200 mg kg-1 (CC200) dan 250 mg kg-1 (CC250). Ikan nila dengan bobot awal 1,96, Citral is a bioactive feed additive compound that can improve carbohydrate utilization. Feed additives added to feed by coating method are expected to be different from those mixed during feed preparation due to the risk of leaching. This study aimed to evaluate the effect of adding citral to feed by coating with different doses on the growth and antioxidant performance of Oreochromis sp. tilapia. The study consisted of four treatments, namely feed without added citral (C0) as a negative control, feed with a dose of citral 100 mg kg-1 by repelleting method (CR100) as a positive control, and feed with different doses of citral by coating method, namely 150 mg kg-1 (CC150), 200 mg kg-1 (CC200) and 250 mg kg-1 (CC250). Tilapia with an initial weight of 1.96±0.00 g were reared in aquariums measuring 50 x 50 x 40 cm at a density of 15 fish per aquarium (200 fish/m3) for 60 days. The test feed was given with a frequency of three times a day at 08.00, 12.00 and 16.00 WIB at satiation. The results showed that the growth performance of tilapia given citral with both repelleting methods was better than feed without citral and with coating method. The CR100 positive control treatment produced the highest final biomass (Bt), final individual weight (Wt), specific growth rate (LPS), total feed consumption (JKP), protein efficiency ratio (REP), and protein retention (RP) and the lowest feed conversion ratio (RKP) than the citral treatment with the coating method at higher dose. The activity of superoxide dismutase (SOD) enzyme in CR100 treatment also showed higher results than other treatments. Based on the results of this study, it can be concluded that tilapia with citral by repelleting method at a dose of 100 mg kg-1 feed (CR100) produced the best growth performance and SOD activity compared to the coating method at higher doses.
Keyword: growth, tilapia, citral, coating, superoxide dismutase

Judul: Growth Performance of Tilapia (Oreochromis niloticus) with the Addition of Antioxidant Astaxanthin to Feed
Abstrak: Astaxanthin sebagai antioksidan diketahui memiliki peran penting terhadap daya imunitas pada ikan, seperti daya tahan terhadap stres lingkungan dan penyakit yang dapat mendukung pertumbuhan ikan. Salah satu produk dengan bahan dasar astaxanthin yang biasa digunakan dalam kegiatan akuakultur ialah Lucantin. Penelitian ini bertujuan mengetahui pengaruh penambahan astaxanthin yang terkandung dalam Lucantin pada pakan terhadap pertumbuhan ikan nila. Penelitian menggunakan rancangan acak lengkap dengan 4 perlakuan, yaitu L0 (100% pakan komersial), L50 (100% pakan komersial + lucantin 50 mg/kg pakan), L100 (100% pakan komersial + lucantin 100 mg/kg pakan), dan L150 (100% pakan komersial + lucantin 150 mg/kg pakan) masing-masing 3 ulangan. Ikan nila merah dengan bobot awal 7,40±0,01 g/ekor dipelihara selama 50 hari dalam akuarium. Hasil penelitian menunjukkan kinerja pertumbuhan ikan nila yang diberi penambahan astaxanthin lebih tinggi dan menunjukkan hasil berbeda nyata (p<0,05) dibanding pakan kontrol atau tanpa penambahan astaxanthin. Parameter yang dapat menggambarkan pertumbuhan ikan seperti nilai biomassa akhir, bobot individu akhir, dan average daily growth menunjukkan pakan perlakuan L100 memiliki nilai yang tertinggi dan berbeda nyata (p<0,05) dari ketiga perlakuan lainnya. Pakan perlakuan L100 juga menunjukkan nilai rasio efisiensi protein dan retensi protein tertinggi yang menggambarkan tingkat efisiensi pemanfaatan pakan. Disamping itu, perlakuan pakan perlakuan L100 juga memiliki nilai rasio konversi pakan dan feed cost per gain terendah di antara perlakuan lainnya. Berdasarkan hasil penelitian ini disimpulkan penambahan Lucantin dosis 100mg/kg pakan dalam pemberian pakan ikan nila menunjukan kinerja pertumbuhan yang terbaik., Astaxanthin as an antioxidant is known to play an important role in the immune power of fish, such as resistance to environmental stress and diseases that can support fish growth. One of products with astaxanthin as the basic ingredient that is commonly used in aquaculture activities is Lucantin. This study aimed to determine the effect of adding astaxanthin contained in Lucantin to feed on the growth tilapia fish. The study used a complete random draft with 4 treatments, namely L0 (100% commercial feed), L50 (100% commercial feed + lucantin 50 mg/kg feed), L100 (100% commercial feed + lucantin 100 mg/kg feed), and L150 (100% commercial feed + lucantin 150 mg/kg feed) 3 replicates each. Red tilapia fish with a starting weight of 7.40±0.01 g/tail were kept for 50 days in an aquarium. The results showed that the growth performance of tilapia fish supplemented with astaxanthin was higher and showed significantly different results (p<0.05) compared to control feed or without the addition of astaxanthin. Parameters that can describe fish growth such as final biomass value, final individual weight and average daily growth show that treatment L100 feed has the highest value and is significantly different (p<0.05) from the other three treatments. Treatment L100 feed also showed the highest protein efficiency ratio and protein retention values which describe the level of feed utilization efficiency. Apart from that, feed treatment L100 also had the lowest feed conversion ratio and feed cost per gain values among the other treatments. Based on the results of this research, it was concluded that addition of Lucantin at a dose of 100 mg/kg to the feed when feeding tilapia showed the best growth performance
Keyword: antioxidant, feed, growth, lucantin, tilapia

Judul: Gelombang soliter internal pada lapisan atmosfiri yang memiliki perubahan kecepatan angin yang cepat
Abstrak: Gelombang internal adalah suatu gelombang yang terjadi di dalam suatu fluida. Gelombang ini muncul karena adanya perubahan rapat massa di setiap lapisan di dalam fluida. Salah satu gelombang internal yang ditemui di lappisan atmosfir adalah gelombang soliter internal, seperti yang terjadi pada fenomena "morning glory" di Australia. pada fenomena "Morning glory" terjadi penurunan tekanan hingga bebrapa milibar.
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