Judul: Improvement of corn quality using physical mechanism and fermentation with Rhizopus oligosporus and its utilization in tilapia (Oreochromis niloticus) feed
Abstrak: Growth performance of fish is highly influenced by the quality of feed, which is determined dominantly by the quality of feedstuff. The research was conducted to evaluate both physical mechanism and fermentation with Rhizopus oligosporus on corn quality and utilization of fermented corn meal by R. oligosporus in feed on the growth of tilapia Oreochromis niloticus. The research containing three steps. First step was using physical mechanism there were soaked, boiled, steamed, and control. The best result from the first step was used in second step, fermented with R. oligosporus. The result was used in third step for biological test. Ten tilapia with 5.0±0.14 g/fish initial body weight were used and stocked in each of fifteen aquaria. The aquaria were equipped with water heater and recirculation system. This research used a complete randomized design with five treatments (0%, 5%, 10%, 15%, and 20% of fermented corn meal) and three replications. The parameters were specific growth rate, feed consumption, feed conversion ratio, protein efficiency ratio, protein retention, fat retention, phosphorus and calcium retention, hepatosomatic index, survival rate, the digestibility of total feed, protein, phosphorus, and calcium. The result showed at first step that steaming gave the best result to reducing phytic acid and increasing digestibility, second step showed fermentation could increasing phosphorus and calcium, protein content, reducing phytic acid and crude fiber fraction also increasing corn digestibility. The third step result showed that 10-15% fermented corn meal in feed gave the best specific growth rate, feed conversion ratio, protein efficiency ratio, protein retention, and protein digestibility (P<0.05). Fat retention, hepatosomatic index, and survival rate were not significantly different (P>0.05) among treatments. The feed up to 15% fermented corn meal level gave the best growth for tilapia fingerling.
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Judul: Pemanfaatan Sekam Padi yang Difermentasi Rhizopus oligosporus dalam Pakan terhadap Pertumbuhan Ikan Nila
Abstrak: This research evaluated the effect of rice husk fermented by Rhizopus oligosporus utilization in feed on the growth, feed efficiency and feed digestibility of Nile tilapia (Oreochromis niloticus). The fish with an initial body weight of 10.00 ± 0.01 g were reared for 60 days in aquaria with the size of 100x40x60 cm3. Fish were fed with diets containing fermented rice husk meal at different concentration, i.e. 0%, 2.5%, 5%, 7.5%, and 10%, respectively. The fish were fed to satiation with frequency three times a day. The results showed that utilization of the fermented rice husk in feed did not affect the average weights, feed consumption, fat retention, daily growth rate, survival, and feed efficiency (P > 0.05). However, the utilization of fermented rice husk in feed affected energy digestibility, protein digestibility, and protein retention (P < 0.05). Based on the results, utilization of fermented rice husk in the feed gave the same result. Utilization of rice husk up to 10% was still in the range of optimum because it resulted in similar daily growth rate and feed efficiency as the control of Nile tilapia.
Keyword: rice husk, Rhizopus oligosporus, fermentation, growth, Nile tilapia

Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf