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 Evaluation of Dairy Cattle Feed with Autoclave Protected Soybean Addition, Cassava as NFC Source, and Sulfur
Abstrak: Penelitian ini bertujuan mengevaluasi secara in vitro pengaruh proteksi kedelai menggunakan autoclave yang disertai dengan suplementasi gaplek sebagai sumber non fiber carbohydrate (NFC) dan sulfur terhadap fermentabilitas, kecernaan ransum, dan populasi mikroba rumen. 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 kontrol tanpa gaplek dan kedelai), P2 (ransum P1+sumber NFC gaplek), P3 (ransum P1+sumber NFC gaplek dan kedelai), P4 (ransum P1+sumber NFC gaplek dan kedelai terproteksi autoclave), dan P5 (ransum P1+sumber NFC gaplek, kedelai terproteksi autoclave, dan Na2SO4). Peubah yang diamati adalah pH, produksi VFA total, konsentrasi amonia, populasi protozoa dan bakteri total, serta kecernaan (KcBk dan KcBO). Data dianalisis dengan sidik ragam (ANOVA) dan uji lanjut berupa uji kontras ortogonal dan Duncan. Hasil penelitian menunjukkan bahwa perlakuan nyata menurunkan produksi VFA total (P<0,05), namun tidak memengaruhi peubah lainnya. Simpulan dari penelitian ini adalah proteksi autoclave terhadap kedelai yang disertai dengan suplementasi gaplek dan sulfur efektif dalam mencegah terjadinya degradasi oleh mikroba di dalam rumen, sehingga diharapkan dapat memberikan kontribusi terhadap kecukupan protein asal ransum yang diserap dalam alat pencernaan pasca rumen., This study aimed to evaluate in vitro the effect of soybean protection using an autoclave accompanied by cassava supplementation as a source of non-fiber carbohydrate (NFC) and sulfur on the fermentability, digestibility of the ration, and rumen microbial population. Randomized Block Design (RBD) was used in this study with 5 ration treatments and 4 groups in the form of the frequency of rumen fluid collection. The treatments consisted of P1 (control diet without cassava and soybeans), P2 (P1 ration+cassava NFC source), P3 (P1 ration+cassava and soybean NFC source), P4 (P1 ration+autoclave protected cassava and soybean NFC source), and P5 (ration P1+source of NFC cassava, autoclave protected soybeans, and Na2SO4). The observed variables were rumen fluid pH value, total VFA concentration, ammonia concentration, protozoa population, and DMD and OMD. Data were analyzed using variance (ANOVA) and further tests in the form of Duncan's test and orthogonal contrast. The results showed that the treatment significantly reduced the total VFA production (P<0.05), but had not affected the other variables. The conclusion of this study is that autoclave protection against soybeans accompanied by cassava and sulfur supplementation is effective in preventing degradation by microbes in the rumen, so it is expected to contribute to the adequacy of protein from the ration absorbed in the post-rumen digestive tract.
Keyword: autoclave, in vitro, protein protection, rumen degradable protein, soybean

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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