Judul: Penambahan Minyak Kedelai Terproteksi terhadap Produksi Gas Metan dan Populasi Mikroba Secara in Vitro
Abstrak: This In vitro study aimed to evaluate the effect of the addition of soybean oil protected by calcium soap into the ration in reducing methane gas on Bali cattle rumen liquid. The experiment was designed in a completely randomized block design with 3 treatments and 4 replication, namely P0 (control diet) P1 (P0 + 5% soybean oil) and P2 (P0 + 5% soybean oil in calcium soap). The variables measured were population of rumen microbes, production of methane gas and total gas. The data were analyzed by ANOVA. The results showed that the soybean oil diet with or without calcium soap protection did not significantly affect the rumen microbial population, the production of methane gas and total gas. It is concluded that supplemention with 5% protected soybean oil did not affect the rumen microbial population, the production of methane gas and total gas.
Keyword: Bogor Agricultural University (IPB), soybean oil, microbial populations, methane gas, calsium soap

Judul: Supplementation on Digestibility and In Vitro Fermentability of Dairy Cattle Rations
Abstrak: Penelitian ini bertujuan untuk menguji minyak kanola, kedelai dan sawit terproteksi sabun kalsium (Ca Soap) secara in vitro. Penelitian ini menggunakan Rancangan Acak Kelompok (RAK) dengan 4 perlakuan dan 3 ulangan: P1 (kontrol tanpa perlakuan), P2 (P1+1% Ca Soap), P3 (P1+2% Ca Soap), dan P4 (P1+3% Ca Soap). Variabel yang diamati meliputi karakteristik fermentasi rumen (pH, konsentrasi volatile fatty acid (VFA) total, konsentrasi ammonia), kecernaan bahan kering dan bahan organik, dan aktivitas mikroba rumen. Data dianalisis dengan menggunakan Analysis of Varian (ANOVA) dan perlakuan yang berbeda nyata akan dilakukan uji lanjut dengan Uji Tukey menggunakan program Minitab 18. Hasil penelitian menunjukkan bahwa perlakuan tidak berpengaruh nyata (P>0,05) terhadap pH, konsentrasi ammonia (NH3), Kecernaan Bahan Organik (KCBO). Jenis minyak juga berpengaruh terhadap Kecernaan Bahan Kering (KCBK). Terdapat interaksi pada perhitungan populasi bakteri dan VFA. Penggunaan minyak nabati terproteksi yaitu minyak kanola, kedelai dan sawit 3% menunjukkan hasil optimal pada fermentabilitas dan kecernaan serta masih berkisar normal., This research aims to test canola, soybean and palm oils protected by calcium soap (Ca Soap) in vitro. This study used a randomized block design with 4 treatments and 3 replications: P1 (control without treatment), P2 (P1+1% Ca Soap), P3 (P1+2% Ca Soap), and P4 (P1+3% Ca Soap). The variables observed included rumen fermentation characteristics (pH, total volatile fatty acid (VFA) concentration, ammonia concentration), dry matter and organic matter digestibility, and rumen microbial activity. Data were analyzed using the Analysis of Variance (ANOVA) and significantly different treatments would be further tested with the Tukey test using the Minitab 18 program. The results showed that the treatment had no significant effect (P>0,05) on pH, concentration of ammonia (NH3), digestibility of organic matter. The type of oil also affects the digestibility of the dry matter. There is an interaction in the calculation of the bacterial population and VFA. The use of protected vegetable oils, namely canola, soybean and palm oil at a level of 3% showed optimal results in rumen fermentability and digestibility and were still in the normal range.
Keyword: Ca soap, canola oil, fermentability, in vitro, palm oil, soybean oil

Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular