Judul: Karakteristik Fermentasi Rumen In vitro dengan Penambahan Sabun Kalsium Minyak Nabati pada Buffer yang Berbeda.
Abstrak: Supplementation of unsaturated fatty acid source from plant in ruminant feed is needed to improve the production and quality of beef meat. Canola oil and flaxseed oil are vegetable oils as potential sources of unsaturated fatty acid. However, to use vegetable oils as sources of unsaturated fatty acids, need to be protected to avoid biohydrogenation by rumen bacteria. The experiment was conducted in a factorial randomized block design with 2 factors and 3 blocks based on rumen sampling time. The first factor was sources of vegetable oils (canola and falxseed) and the second factor was kind of buffer ( Kajikawa and Mc.Dougall). Variables observed were pH value, N-NH3 concentration, total volatile fatty acid (VFA), dry matter and organic matter digestibility. The result showed that there was no interaction between sources of diet and buffer. Supplementation of canola and flaxseed oils protected by calcium soap at level 6% did not affect pH value, dry matter digestibility, rumen protozoa and total bacteria. The use of different buffers affected pH value, dry matter digestibility, rumen protozoa and total bacteria.
Keyword: canola oil, fermentation, flaxseed oil, NH3, VFA

Judul: Profil Asam Lemak dengan Penambahan Sabun Kalsium Minyak Kanola dan Minyak Flaxseed di Rumen In Vitro.
Abstrak: Supplementation of vegetable oils containing high unsaturated fatty acids is a common practice in ruminant feed to increase the quality of meat. The objective of this research was to assess the effect of canola and flaxseed oils protected with Ca soap in rumen during fermentation in vitro at 4 and 8 hours. The design used in this experiment was a rendomized complete block design with 3 treatments and 4 replications. The treatments consisted of forage and concentrate with ratio 60 : 40 (control), control + Ca soap canola oil 6% and control + Ca soap flaxseed oil 6%.Variables observed in this research were population of rumen microbes (total bacteria and protozoa population), total VFA, molar proportion, estimation of methane production, and fatty acid profile at 4 and 8 hours incubation. The results showed that the treatments did not affect the population of rumen microbes. The use of Ca soap flaxseed oil increased total VFA, proportion of propionate and methane production estimation. At the 4 hour incubation, Ca soap canola oil suffered considerable biohydrogenation 79.35%, while Ca soap flaxseed oil (49.36%). At the 8 hour fermentation, Ca soap falxseed oil suffered considerable biohydrogenation at 66.24%, while Ca soap canola oil at 81.41%.
Keyword: Biohydrogenation, Ca soap, canola oil, flaxseed oil

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