Judul: Resistance of amide in ruminal system and its effectiveness in modifying fatty acid composition in rat as post ruminal model
Abstrak: Pemberian pakan tinggi asam α-linolenat dan khususnya asam lemak dengan rantai yang lebih panjang, yaitu EPA dan DHA, dapat memperbaiki kandungan asam lemak tak jenuh rantai ganda atau polyunsaturated fatty acids (PUFA) n-3 dalam jaringan daging domba untuk memenuhi standar kesehatan yang optimal bagi diet manusia. Pada ruminansia, diet asam lemak mengalami biohidrogenasi yang ekstensif oleh mikroorganisme rumen sehingga penyerapan didominasi oleh asam lemak jenuh yang mengarah pada pembentukan lipoprotein berdensitas sangat rendah atau very-low-density lipoprotein (VLDL). Biohidrogenasi asam lemak dalam rumen dapat diatasi dengan melindungi asam lemak, terutama PUFA n-3 dalam bentuk amida. Penelitian ini dimulai dari tahap pembuatan amida minyak ikan, uji ketahanan dalam sistem rumen, dan efektivitasnya dalam mengubah profil lemak pada hewan model. Identifikasi gugus amida yang terbentuk dilakukan dengan spektroskopi inframerah, sedangkan GC-MS digunakan untuk mengetahui kadar senyawa amida yang terbentuk. Pengujian dalam sistem rumen secara in vitro memperlihatkan bahwa senyawa amida tetap terdeteksi dalam kultur setelah inkubasi selama 24 jam, dengan tingkat degradasi masing-masing 30% untuk pemberian 5% dan 13% untuk pemberian amida sebesar 10%. Namun kondisi ini belum mampu memperbaiki kecernaan substrat dalam kultur. Kondisi lingkungan rumen, seperti pH, produksi gas, VFA, NH3 dan protein mikrob, masih dapat dipertahankan pada kisaran normal, dan tidak berbeda dari kontrol. Namun jumlah protozoa mulai menurun, kemungkinan karena mengalami lisis akibat pemberian amida. Pada pengujian ini, amida belum mampu mengatasi gangguan fermentasi akibat pemberian lemak, terutama asam-asam lemak tak jenuh. Hal ini ditandai dengan rendahnya degradasi bahan kering dan bahan organik dibandingkan dengan kontrol yang tidak mendapat sumber lemak.
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Judul: Fermentabilitas, Populasi Protozoa, Alantoin Urin, dan Neraca Nitrogen Domba Lokal Calon Induk yang Diberi Sumber Asam Lemak Tak Jenuh Berbeda
Abstrak: The addition of poly unsaturated fatty acid (PUFA) in feed is needed for energy source and reproductive function. However, fat supplementation to the diet can disrupt the fermentation system, microbial population in the rumen, and limit the synthesis by rumen microbes. The objective of this research was to study the influences of feed containing different sources of unsaturated fatty acid on protozoa population, rumen fermentability, the urinary allantoin excretion rate, and the nitrogen (N) balance in the body. Twelve three-months old post weaning local female sheep were used in this study. The sheep were allocated in a Randomized Block Design and divided into three groups based on body weight and subjected to four treatments. Four treatments were M0 = control diet, MJ = diet containing 1.5% corn oil, MIL = diet containing 1.5% lemuru fish oil, MILT = diet containing 1.5% protected lemuru fish oil. Data were analyzed using analysis of variance and any significant differences were further tested using contrast orthogonal. The results showed that the protozoa population, ruminal NH3 level, excretion of allantoin, and N retention were not affected (P>0.05) by dietary supplementation, but the volatile fatty acid (VFA) level was very significantly (P<0.01) increased with the addition of corn oil (171.49 mM) and lemuru fish oil (141.42 mM). It is concluded that different sources of unsaturated fatty acid supplementation had no influence in protozoa population, rumen activity, and urinary allantoin, but could improve the rate of VFA.
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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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