Judul: Fermentability and Digestibility of Feed Added Slow Relase Urea-Nitrate In Vitro.
Abstrak: Penelitian ini bertujuan menguji pengaruh penambahan slow release urea-nitrat dalam ransum secara in vitro. Penelitian ini menggunakan rancangan acak kelompok 5 perlakuan dan 4 ulangan. Perlakuan terdiri dari P0 = ransum kontrol; P1 = P0 + urea; P2 = P0 + urea-nitrat; P3 = P0 + urea-nitrat dilapisi dengan molases; P4 = urea-nitrat dilapisi dengan limbah cair sari kurma. Peubah yang diamati adalah kecernaan bahan kering (KcBK), kecernaan bahan organik (KcBO), konsentrasi amonia (NH3), derajat keasaman (pH), volatile fatty acid (VFA) total, sintesis protein mikroba (SPM), total produksi gas, dan gas metan. Data dianalisis menggunakan analysis of variance (ANOVA) dan perlakuan yang berbeda nyata akan dilakukan uji lanjut dengan uji duncan menggunakan statistical product and service solutions (SPSS) 25. Hasil penelitian menunjukkan bahwa perlakuan tidak berpengaruh nyata (P>0,05) terhadap nilai KcBK, KcBO, VFA total, pH, SPM, total produksi gas, dan gas metan. Perlakuan yang berpengaruh nyata (P<0,05) adalah konsentrasi amonia (NH3). Simpulan penelitian ini adalah penambahan slow release urea-nitrat belum mampu menurunkan konsentasi amonia., This study aimed to examine the effect of the addition slow release urea-nitrate in rations in vitro. This study used a randomized block design with 5 treatments and 4 replications. The treatment consisted of P0 = control ration; P1 = P0 + Urea; P2 = P0 + urea-nitrate; P3 = P0 + urea-nitrate coated with molasses; P4 = urea-nitrate coated with palm juice liquid waste. The observed variables were dry matter digestibility (KcBK), organic matter digestibility (KcBO), ammonia concentration (NH3), degree of acidity (pH), total volatile fatty acid (VFA), microbial protein synthesis (SPM), total gas production, and methane gas. Data were analyzed using analysis of variance (ANOVA) and significantly different treatments would be further tested with Duncan's test using statistical product and service solutions (SPSS) 25. The results showed that the treatment had no significant effect (P>0.05) on the KcBK, KcBO, total VFA, pH, SPM, total gas production, and methane gas. The treatment that had a significant effect (P<0.05) was the concentration of ammonia (NH3). The conclusion of this study was the addition of slow release urea-nitrate has not been able to reduce the concentration of ammonia.
Keyword: ammonia concentration, in vitro, methane gas, slow release urea-nitrate

Judul: Slow Release Urea Nitrate with Acetaldehyde and Formaldehyde Coating Techniques against Fermentability and In Vitro Digestibility
Abstrak: Penelitian ini bertujuan mengevaluasi pengaruh pemberian coating asetaldehid dan formladehid terhadap fermentabilitas, kecernaan, serta produksi gas dalam rumen secara in vitro. Penelitian ini menggunakan rancangan acak lengkap (RAL) untuk menguji parameter pH, kecernaan bahan kering (KcBK), kecernaan bahan organik (KcBO), konsentrasi amonia, produksi gas, gas metan dan volatile fatty acid (VFA) total serta uji lanjut Tukey HSD. Data yang diperoleh dianalisis dengan menggunakan software SPSS versi 25. Hasil penelitian tersebut menunjukkan bahwa pemberian coating urea nitrat berlapis asetaldehid dan formladehid tidak berpengaruh nyata terhadap pH, KCBK, KCBO, VFA, gas metan dan konsentrasi amonia di dalam rumen. Akan tetapi berpengaruh nyata (P <0,05) dalam menurunkanproduksi gas. Dapat disimpulkan bahwa Penggunaan slow release urea nitrat (SRUN) dengan bahan coating asetaldehid lebih efektif memperlambat laju degradasi amonia dari pada bahan coating formaldehid, namun bahan coating asetaldehid dan formaldehid tidak berdampak terhadap fermentasi rumen, kecernaan, dan produksi metana., This study aimed evaluate the effect of coating acetaldehyde and formaldehyde on fermentability, digestibility, and gas production in the rumen in vitro. This study used a completely randomized design (CRD) to test the parameters of pH, dry matter digestibility (DMD), organic matter digestibility (OMD), ammonia concentration, gas production, methane gas and volatile fatty acid (VFA) ) and differences among mean values were examined using Tukey HSD test. The data obtained were analyzed using SPSS software version 25. The results showed that the coating of urea nitrate coated with acetaldehyde and formaldehyde had no significant effect on pH, DMD, OMD, VFA, methane gas and ammonia concentration in the rumen. However, it had a significant effect (P <0.05) in reducing gas production. The use of slow release urea nitrate (SRUN) with acetaldehyde coating materials is more effective in slowing the rate of ammonia degradation than formaldehyde coating materials, but acetaldehyde and formaldehyde coating materials have no impact on rumen fermentation, digestibility, and methane production.
Keyword: ammonia, acetaldehyde, formaldehyde, urea nitrate coatings

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology