Judul: Karakteristik Fermentasi Silase Daun Singkong (Manihot esculenta Crantz) dengan Aditif Gliserol dan Ekstrak Tanin Chesnut
Abstrak: Cassava leaves (Manihot esculenta Crantz) productivity has a big potential to be valuable protein supplement for ruminant. However, due to the abundant availability when crop, cassava leaves requires a storage technology to maintain its nutritious composition. The one of better way is by ensilage. The ensiling process of cassava leaves required additives because its low content of WSC. Additives used in this present study were glycerol and chesnut tannin extract. Meta-analysis of glycerol supplementation in vitro did to support the hypothesis regarding of glycerol usage to substitute energy source as silage additives. This study aimed to evaluate the glycerol supplementation on rumen fermentation characteristics in vitro by quantitatively meta-analysis, to evaluate the fermentation characteristics of cassava leaves silage with glycerol and chestnut tannin extract additives during ensilage and in vitro gas production. Meta-analysis quantitatively was applied to 13 experiments and 42 treatments dealing with glycerol supplementation in ruminant. Data were estimated by linear regression of each parameter and analyzed by general linier model procedure with glycerol levels as fixed effect. Data for both fermentation characteristics of cassava leaves silage and its in vitro gas production were analyzed using analysis of variance then significant means were separated using Duncan multiple range F-test. Cassava leaves was ensiled using four different types of additive on the laboratory-scale silo. They were control (without additive, S0), glycerol 3% DM (SG), chesnut tannin 3% DM (ST), and mix of glycerol 3% DM and chesnut tannin 3% DM (SGT). Parameters on meta-analysis and in vitro gas production study were in vitro digestibility, rumen fermentation characteristics and total gas production. Parameters on silage study were nutrient composition, organic acids and N-NH3 concentration. Glycerol supplementation on meta-analysis quantitatively did not affect the in vitro digestibility and total VFA. Total VFA insignificantly showed propiogenic characteristics. It significantly decreased molar proportion of acetate and iso-valerate. In contrast, molar proportion of propionate, butyrate and valerate significantly increased, and thus the ratio of acetate to propionate became declined linearly. Methane production decreased linearly although the total gas production significantly increased as an increasing levels of glycerol supplementation but showed low enteric methane and no effect for microbial protein production. Every single cassava leaves silages in present study showed well-preserved quality depended on high concentration of lactic acid, not detected butyric acid, low concentration of N-NH3 although the pH value slightly higher. In addition, the well-preserved quality also supported by a low reduction of OM content (about 0.2%) and not changed CP content in silage between week 0 and 4. Rumen fermentation characteristics of cassava leaves silage by in vitro gas production showed an increasing IVOMD and total VFA production between week 0 and 4, but the silage treatment was not significant on each week. Glycerol as silage additive at week 0 showed propiogenic properties but not appeared on SG and SGT week 4. Contrary, the main properties of chesnut tannin was shown on in vitro gas production of ST and SGT week 4 that reduced proportion of N-NH3 and iso-acid production related to amino acid degradation. Based on results, it can be concluded that meta-analysis
Keyword: chesnut tannin, glycerol, in vitro, Manihot esculenta Crantz, silage

Judul: Karakteristik Fermentasi Rumen dan Performa Domba Teradaptasi yang Diberi Pakan Silase Daun Singkong (Manihot esculenta sp.) dengan Taraf Berbeda
Abstrak: This experiment aimed to study the effect of provision of cassava leaves silage (CLS) as substitution for concentrate on rumen fermentation characteristics and performance of Javanesse Thin Tail Sheep. The experimental design used was block randomized design (4x4) using 16 male sheep of nine months old with body weight of 15.36 ± 2.59 kg and they were placed in the individual metabolic cage. The treatments were T0 (100% of napier grass), T1 (60% napier grass + 40% concentrate), T2 (60% napier grass + 20% concentrate + 20% CLS), and T3 (60% napier grass + 40% CLS). The results showed that provision of cassava leaves silage in the rations decreased (P<0.05) nutrient digestibility but increased (P<0.05) energy and protein consumption and rumen fermentability. Provision of CLS at level 20% (T2) had average daily gain, EPP, and IOFC similar to those of 40% concentrate treatment (T1). Provision of CLS at level 40% (T3) had average daily gain, EPP, and IOFC significantly lower (P<0.05) than those of 20% CLS and 40% concentrate treatment. It is concluded that CLS can be given at level of 20% of total ration which is equal to 50% concentrate. Feeding sheep only with napier grass do not fulfill their nutrient requirement for proper growth.
Keyword: Sheep, Rumen Fermentation Characteristics, Performance, Cassava Leaves Silage

Judul: Teknik penentuan posisi bintang berdasarkan pelat foto overlapping
Abstrak: Bintang adalah salah satu objek langit yang menarik untuk diamati. Untuk itu, pengetahuan tentang posisi bintang sangat diperlukan. Posisi bintang di langit dapat dihitung melalui foto bintang. Fotografi astronomi atau astrometri merupakan ilmu yang mempelajari metode untuk menentukan posisi bendabenda langit seperti bintang berdasarkan pelat foto (Kamp, 1967). Sebuah pelat foto berisi citra bintang-bintang yang sudah diketahui posisinya berdasarkan katalog dan citra bintang-bintang yang belum diketahui posisinya. Posisi bintang yang ada di katalog dinyatakan dengan (a,3). Bintang yang belum diketahui posisinya lebih banyak jumlahnya daripada bintang yang sudah diketahui posisinya. Citra bintang pada pelat foto berupa sebuah titik dalam bentuk tetap. Posisinya pada pelat merupakan hasil pengukuran pada bidang kartesius dan dinyatakan dengan (1;,fl). Hasil pengukuran tersebut kemudian direduksi menjadi koordinat terukur (x,y). Hubungan antara (a,3) dan (x,y) didekati dengan sebuah deret dengan konstanta-konsranta deret merupakan konstanta pelat. Nilai konstanta pelat diperoleh dengan menggabungkan hasil pengukuran posisi bintang pada masing-masing pelat menjadi sebuah persamaan normal (Jefferys, 1963). Hasil akhir dari gugus persamaan normal tersebut dijabarkan dalam bentuk nOlasi matriks partisi dan berupa sebuah sistem persamaan linier Ax = b di mana A adalah matriks jarang, dan x merupakan konstanta pelar yang akan dicari nilainya. Untuk menyelesaikan sistem persamaan linier terse but digunakan metode transformasi given. Konstanta pelat yang sudah diperoleh dengan menyelesaikan sistem persamaan linier di atas, kemudian disubtitusi ke sebuah persamaan untuk memperoleh posisi bintang yang tidak tercantum dalam katalog. .
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