Judul: Urea treated cocoa pod as barley grain substitution in ruminant ration on microbial metabolism and feed degradation (Rusitec Study)
Abstrak: Limited sustainable supply of high quality feedstuff is the major constrain in ruminant production in most of tropical countries. Aim to convert underutilized cocoa pod to quality feedstuff and its inclusion in ruminant ration have been done. Cocoa pod was treated with 20 g urea per kg fresh material. The effects of replacing barley grain by urea treated cocoa pod on methane release, SCFA production as well as the amount and efficiency of microbial-N fixation in Rusitec have been studied. The experiment included six different rations (T1 = 10 g/d hay; T2 = T1 + 4 g/d barley-soybean mixture (barley); T3 = T1 + 3 g barley + 1 g cocoa pod); T4 = T1 + 2 g barley + 2 g cocoa pod; T5 = T1 + 1 g barley + 3 g cocoa pod and T6 = T1 + 4 g cocoa pod) and three running of Rusitec in a block random design. Substitution of barley by urea treated cocoa pod up to 100% in hay based rations did not decrease the rate of ration DM disappearance, and fiber degradation even tended to be increased. Microbial N-fixation decreased with the inclusion of cocoa pod in the rations, but the efficiency of microbial N-fixation was increased in line with the cocoa pod level. Methane release per unit NDF disappearance decreased inversely to the cocoa pod level. Urea treated cocoa pod cannot replace barley/soybean meal-mixture equivalently, but can be used as a feedstuff for low performance ruminants.
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Judul: Nutritional Properties of Cocoa Pods as Ruminant Feedstuff
Abstrak: An attempt to increase cocoa pods quality feed for ruminant have been done using fermentation techniques with or without urea addition. Five treatments (Fresh cocoa pod = C; fermentation with addition urea 0 g/kg = U0 or ensilage; 10 g/kg = U1; 20 g/kg = U2 and 30 g/kg fresh substances of cocoa pods) have been examined for their effect on pH, proximate composition, N-fractions, amino acid compositions, cell wall constituents, anti nutritive compounds, in vitro gas production (Gb), estimate organic matter digestibility (OMD) and metabolizable energy (ME) of cocoa pods. Ensilage (U0) improve feed values of cocoa pods by weakening the lingo-cellulose or –hemicellulose bonds, resulting in higher in vitro gas production as well as higher OMD and ME contents compare to fresh cocoa pods. The protein value of cocoa pods, expressed as true protein (TP) or non ammonia nitrogen (NAN) minus urea nitrogen (UR) was also improved. Addition of urea affected the composition of the fibre fraction as to the proportion of NDF, ADF and ADL and the content of TP was slightly increased. Urea treatment increased Gb, OMD and ME compared to ensiled or fresh cocoa pods. The optimum level of urea for maximum Gb was 6.7 g/100 g DM cocoa pods. The optimum level to reach maximum OMD and ME were also reached at urea level 6.5 – 6.7 g/100 g DM cocoa pods.
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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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