Judul: Slow Release Urea Nitrate with Starch Polymer Coating Technique for Fermentation and Rumen Digestibility In Vitro, Slow Release Urea Nitrate with Starch Polymer Coating Technique for Fermentation and Rumen Digestibility In Vitro
Abstrak: Penelitian ini bertujuan untuk mengevaluasi pengaruh teknik penyalut polimer amilum yang dilakukan secara in vitro pada urea-nitrat sebagai bahan pakan aditif bagi ruminansia. Penelitian ini menggunakan rancangan acak kelompok (RAK) dengan 5 perlakuan dan 4 kelompok. Perlakuan terdiri dari P0 = ransum kontrol; P1 = P0 + urea tanpa penyalut; P2 = P0 + urea-nitrat tanpa penyalut; P3 = P0 + urea-nitrat dengan penyalut pati sagu; P4 = P0 + urea-nitrat dengan penyalut pati singkong. Parameter yang diamati yaitu kecernaan bahan kering (KCBK), kecernaan bahan organik (KCBO), pH, volatile fatty acid (VFA), konsentrasi amonia (NH3), sintesis protein mikroba, total gas produksi dan produksi gas metan. Hasil penelitian menunjukkan bahwa pemberian ransum perlakuan tidak berpengaruh nyata (P>0,05) terhadap KCBK, KCBO, pH, VFA, sintesis protein mikroba, total produksi gas dan produksi gas metan, tetapi berpengaruh nyata terhadap konsentrasi NH3. Penambahan urea-nitrat dengan penyalut pati singkong dapat menurunkan konsentrasi amonia dan tidak berdampak terhadap fermentasi, kecernaan rumen dan produksi gas metan., This research aimed to evaluate the effect of starch polymer coating techniques carried out in vitro on urea-nitrate as a feed additive for ruminants. This study used a randomized block design (RBD) with 5 treatments and 4 groups. The treatment consisted of P0 = control ration; P1 = P0 + uncoated urea; P2 = P0 + uncoated urea-nitrate; P3 = P0 + urea-nitrate with sago starch coating; P4 = P0 + urea-nitrate with cassava starch coating. Observed parameters were dry matter digestibility (DMD), organic matter digestibility (OMD), pH, volatile fatty acids (VFA), ammonia concentration (NH3), microbial protein synthesis, total gas production and methane production. The results showed that the treatment ration had no significant effect (P>0.05) on DMD, OMD, pH, VFA, protein synthesis microbes, total gas production and methane production, but had a significant effect on NH3 concentrations. The addition of urea-nitrate coating with cassava starch can reduce ammonia concentrations and has no impact on fermentation, rumen digestibility and methane gas production.
Keyword: ammonia, coating urea-nitrat, in vitro, methane, starch

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