Judul: In vitro Evaluation of Dairy Cow Rations with Formaldehyde Protected Soybean Based and Corn as NFC Source and Sulfur Supplementation
Abstrak: Tujuan penelitian ini adalah mengevaluasi efektivitas proteksi kedelai menggunakan formaldehid yang disuplementasi dengan sumber NFC berupa jagung dan mineral sulfur dalam ransum sapi perah, melalui aktivitas mikroba di dalam rumen in vitro. Rancangan Acak Kelompok (RAK) digunakan dalam penelitian ini dengan 5 perlakuan ransum dan 4 kelompok berupa frekuensi pengambilan cairan rumen. Perlakuan terdiri atas P1 (Ransum tanpa penggunaan jagungdan tanpa penggunaan kedelai), P2 (Ransum P1 + jagung sebagai sumber NFC), P3 (Ransum P2 + biji kedelai tidak diproteksi), P4 (Ransum P2+ biji kedelai diproteksi formaldehid 1,0%), dan P5 (Ransum P4 + Mineral Na2SO4). Peubah yang diukur berupa pH, fermentabilitas (produksi VFA total dan konsentrasi NH3), populasi protozoa dan bakteri total, serta kecernaan ransum (koefisien cerna bahan kering dan bahan organik). Data dianalisis dengan analysis of varians (ANOVA) dan perbedaan hasil diuji lanjut menggunakan Duncan. Hasil penelitian menunjukkan bahwa proteksi kedelai dan penambahan jagung nyata menurunkan konsentrasi amonia dan konsentrasi VFA total (P<0,05), namun tidak mempengaruhi peubah lainnya. Simpulan penelitian ini adalah proteksi kedelai menggunakan formaldehid yang disertai dengan suplementasi jagung efektif mengurangi degradasi kedelai oleh mikroba rumen, sehingga diharapkan dapat meningkatkan sumbangan protein ransum yang diserap di organ pasca rumen., The purpose of this study was to evaluate the effectiveness of soybean protection using formaldehyde supplemented with NFC sources in the form of corn and mineral sulfur in dairy cattle rations, through microbial activity in the rumen in vitro. Randomized Block Design (RAK) was used in this study with 5 ration treatments and 4 groups in the form of rumen intake frequency. The treatments consisted of P1 (Ration without the use of corn and without the use of soybeans), P2 (Ration P1 + corn as a source of NFC), P3 (Ration P2 + unprotected soybean seeds), P4 (Ration P2+ soybean seeds protected formaldehyde 1.0%), and P5 (Ration P4 + Mineral Na2SO4). The variables measured were pH, fermentability (total VFA production and NH3 concentration), total population of protozoa and bacteria, and feed digestibility (digestibility coefficient of dry matter and organic matter). Data were analyzed by analysis of variance (ANOVA) and the difference in results was further tested using Duncan. The results showed that soybean protection and corn addition significantly reduced ammonia concentration and total VFA concentration (P<0.05), but did not affect other variables. The conclusion of this research is that soybean protection using formaldehyde accompanied by corn supplementation is effective in reducing soybean degradation by rumen microbes, so it is expected to increase the contribution of ration protein absorbed in postrumen organs.
Keyword: corn, formaldehyde, non fiber carbohydrate, rumen fermentation, soybean

Judul: In Vitro Digestibility and Ruminal Fermentation in Dairy Cattle Rations Based on NFC from Cassava Meal and Protected Soybean by Formaldehyde
Abstrak: Rasio Rumen Degradable Protein (RDP) dan Rumen Undrgradable Protein (RUP) yang ideal diketahui mampu meningkatkan produktivitas ternak sapi perah. Kedelai merupakan salah satu bahan pakan konsentrat yang memiliki kandungan protein kasar tinggi dan asam amino yang lengkap, namum karena sifatnya yang mudah terdegradasi dalam rumen dibutuhkan upaya untuk memproteksi protein pada kedelai, salah satunya dengan penambahan formaldehid. Ketersediaan energi juga harus diperhatikan untuk digunakan dalam proses sintesis protein mikroba. Mineral sulfur dibutuhkan untuk mensintesis asam amino bersulfur seperti metionin dan sistein. Penelitian bertujuan mengevaluasi tingkat kecernaan dan fermentabilitas ransum yang menggunakan komponen Non-Fiber Carbohydrates (NFC) asal gaplek dan kedelai terproteksi menggunakan formaldehid 1% secara in vitro menggunakan metode Tilley dan Terry (1963). Rancangan percobaan yang digunakan adalah Rancangan Acak Kelompok (RAK) dengan 5 perlakuan dan 4 ulangan, pengelompokkan berdasarkan waktu pengambilan cairan rumen dijadikan sebagai ulangan. Data dianalisis dengan analisis varian (ANOVA) dan uji kontras ortogonal menggunakan aplikasi SPSS versi 25. Hasil evaluasi ransum secara in vitro menunjukkan bahwa penambahan NFC asal gaplek, kedelai terproteksi formaldehid, dan suplementasi sulfur dalam ransum tidak memberikan pengaruh yang nyata (P>0,05) terhadap fermentabilitas rumen in vitro. Kecernaan bahan kering dan bahan organik meningkat (P<0,05) pada ransum yang ditambahkan NFC asal gaplek., An ideal ratio of Rumen Degradable Protein (RDP) and Rumen Undegradable Protein (RUP) is known to increase the productivity of dairy cattle. Soybean contains high crude protein and complete amino acid, besides that most of the protein components in soybeans degraded quickly in rumen so we need to protect the protein. Energy availability is required to support the microbial protein synthesis process. Sulfur also needed to synthesize sulfuric amino acids like methionine and cysteine. This study aimed to evaluate the digestibility and fermentability of dairy cattle ration with the addition of Non-Fiber Carbohydrates (NFC) sources from cassava meals and protected soybeans by formaldehyde using Tilley and Terry’s (1963) in vitro method. The experimental design was a randomized block design with 5 treatments and 4 repeats, grouping based on the rumen fluid collection time. Data were analyzed with analysis of variance (ANOVA) and contrast’s multiple range test using the SPSS 25th version. The result of the in vitro rations evaluations showed that the addition of NFC, protected soybean, and sulfur supplementation in rations had no significant effect (P>0.05) on rumen fermentability. Dry matter digestibility and organic matter digestibility increased (P<0.05) in the ration that was added with NFC from cassava meals.
Keyword: formaldehid, gaplek, kedelai, sulfur, cassava meal, formaldehyde, soybean, sulfur

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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