Judul: Population of intestinal microflora, digestive enzyme activity and growth of catfish Clarias sp. were given by probiotic Bacillus megaterium
Abstrak: Kegiatan budidaya ikan secara intensif memiliki banyak permasalahan diantaranya kecernaan pakan yang rendah, serangan penyakit yang meningkat dan kualitas air yang menurun. Kecernaan pakan dalam budidaya ikan memiliki peran penting dalam keberhasilan proses budidaya. Kecernaan pakan berpengaruh terhadap pertumbuhan ikan dan biaya produksi dalam proses budidaya. Kecernaan pakan dapat ditingkatkan dengan meningkatkan enzim-enzim pencernaan yang mampu merombak nutrien dalam pakan. Peningkatan enzim-enzim pencernaan dapat dilakukan dengan memanfaatkan bakteri probiotik. Probiotik memiliki kemampuan dalam menghasilkan enzim-enzim pencernaan yang dapat meningkatkan kecernaan pakan dan pertumbuhan ikan. Penelitian ini bertujuan untuk mengevaluasi pengaruh pemberian bakteri probiotik terhadap populasi mikroflora intestinal, aktivitas enzim pencernaan dan pertumbuhan ikan lele., An increase in disease, low digestibility of feed, and a decrease in water quality are several problems in intensive fish farming. Digestibility of feed in aquaculture also has a high impact to the fish growth and production cost, which are affecting to the success of the farming. Actually, this can be improved by developing the activity of digestive enzymes to break down the nutrients in the feed. The effort to increase digestive enzymes activity can be done by using probiotic bacteria. Probiotic has an ability to produce digestive enzymes to improve digestibility and growth of fish. This study aimed to analyze the effect of probiotic bacteria on the population of intestinal microflora, digestive enzyme activities and growth of catfish.
Keyword: Digestive enzyme activity, Microflora intestinal, Growth, Probiotic

Judul: Commercial Probiotic Supplementation on Biofloc System and Its Effects on Growth Performance and Health Status of Catfish (Clarias sp.) Fry
Abstrak: Teknologi bioflok diketahui dapat meningkatkan produktivitas budidaya dan probiotik Bacillus sp. dapat meningkatkan respons imun, menurunkan FCR, serta meningkatkan kualitas air budidaya ikan lele. Penelitian ini bertujuan mengevaluasi pengaruh suplementasi probiotik komersial pada sistem bioflok dalam meningkatkan kinerja pertumbuhan dan status kesehatan benih ikan lele (Clarias sp.). Penelitian menggunakan rancangan acak lengkap (RAL) dengan tiga perlakuan dan dua ulangan, yaitu ikan dipelihara tanpa aplikasi bioflok dan penambahan probiotik komersial (K), ikan dipelihara dengan aplikasi bioflok (BF), serta ikan dipelihara dengan aplikasi bioflok dan penambahan probiotik komersial 0,6 mL m-2 tiga hari sekali. Ikan lele yang digunakan memiliki panjang rata-rata 0,86±0,03 cm dan bobot rata-rata 0,0069±0,00 g dipelihara dengan padat tebar 2.500 ekor m-2 selama 21 hari. Parameter yang diamati yaitu laju pertumbuhan panjang harian, laju pertumbuhan bobot harian, relative percent survival, koefisien keragaman, rasio konversi pakan, kelimpahan bakteri total, eritrosit total, leukosit total, kadar hemoglobin, dan kadar hematokrit. Penambahan probiotik komersial dalam sistem bioflok mampu meningkatkan kinerja pertumbuhan dan status kesehatan benih ikan lele, ditunjukkan oleh nilai relative percent survival mencapai 52,35%, serta nilai gambaran darah yang lebih baik dibandingkan dengan dua perlakuan lainnya. Penambahan probiotik komersial pada sistem bioflok dapat diterapkan untuk meningkatkan produktivitas dan status kesehatan ikan lele., Biofloc technology is known to enhance aquaculture productivity, and the probiotic Bacillus sp. can improve immune response, reduce feed conversion ratio (FCR), and enhance water quality in catfish farming. This study aimed to evaluate the influence of commercial probiotic supplementation in a biofloc system on the growth performance and health status of catfish (Clarias sp.) juveniles. The study employed a completely randomized design (CRD) with three treatments and two replications: fish reared without biofloc and commercial probiotic supplementation (K), fish reared with biofloc application (BF), and fish reared with biofloc application and commercial probiotic supplementation at a rate of 0,6 mL m-2 every three days. The catfish used had an average length of 0,86±0,03 cm and an average weight of 0,0069±0,00 g, with a stocking density of 2.500 individuals m-2 for a duration of 21 days. The parameters observed were daily length growth rate, daily weight growth rate, relative percent survival, coefficient of variation, feed conversion ratio, total bacterial abundance, total erythrocytes, total leukocytes, hemoglobin level, and hematocrit level. The addition of commercial probiotics in the biofloc system improved the growth performance and health status of catfish juveniles, as indicated by a relative percent survival value of 52,35% and better blood profiles compared to the other two treatments. The addition of commercial probiotics in the biofloc system can be implemented to enhance the productivity and health status of catfish.
Keyword: biofloc, Clarias sp., growth, health status, probiotic

Judul: : Persamaan Tunggal sebagai Representasi Kurva Komposit
Abstrak: A mathematical method is introduced to represent a composite curve based on an extension of analytic geometry. The representation is given either with a single equation or with two equations, in the case of parametric representation. This method permits the representation of composite curves in similar manner to the conventional representation of non-composite curves. Some mathematical tools, including Heaviside unit step function and periodizer function, are used in the establishment of a single equation. In this paper, regular equations of regular and irregular polygon, as well as composite curves of two dimensions, are implemented using a computer algebraic system, Mathematica.
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