Judul: Analisis hubungan curah hujan - limpasan langsung sub sub daerah aliran sungai ciliwung hulu
Abstrak: Suatu daerah aliran sungai (DAS) dapat dipandang sebagai sistem yang menentukan kontribusi curah hujan terhadap limpasan. Selama sifat-sifat fisik DAS tidak berubah, variasi-variasi dalam hubungan curah hujan dengan limpasan merupakan akibat adanya variasi hujan serta faktor kebasahan awal DAS.
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Judul: Analisis hidrograf dan faktor-faktor yang mempengaruhi besar limpasan sub das Ciesek (Daerah Aliran Sungai Ciliwung)
Abstrak: Penelitian ini bertujuan untuk mengetahui parameter- parameter karakteristik DAS, melihat pengaruh tipe hujan dan fisiografik DAS terhadap pola hidrograf satuan, menyusun hidrograf satuan untuk lama waktu hujan efektif tertentu, dan mendapatkan model hubungan antara beberapa parameter hidrograf satuan. Hidrograf merupakan gambaran dari sifat aliran limpas- an terhadap waktu. Bentuk dan ukurannya dipengaruhi oleh faktor fisiografik dan curah hujan. Hidrograf satuan dengan tipe hujan efektif dipercepat (advanced), waktu untuk mencapai puncak limpasan lebih cepat, sedangkan hidrograf satuan dengan tipe hujan efektif diperlambat (delayed), waktu untuk mencapai puncak limpasan juga lebih lama. Waktu untuk mencapai puncak limpasan juga dipengaruhi oleh kondisi kelembaban tanah pada permulaan turunnya hujan. Parameter yang diperoleh dari hasil analisis hidrograf satuan untuk masing-masing kejadian hujan, 7-9-1986; 7-11-1986; 9-11-1986; 4-1-1987; 6-6-1987 dan 6-11-1987...
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Judul: Responses on Performance and Minerals Digestibility by Novel Consensus Bacterial 6-Phytase  Variant (PHY-G) Supplementation in Broiler Diet
Abstrak: Plant feedstuffs normally contain phytic acid which poorly hydrolized by monogastric especially broiler. Further, 80% of phosphorus (P) in plant feedstuff is complexed with phytic acid. In that case, high amount of inorganic P sources is needed to fulfill P requirement. Since it has capability to bind with some nutrients such as bi- or trivalent minerals and amino acids then phytase is widely utilized in poultry feed to improve the nutrient digestibility. Today, the use of 500-1000 FTU phytases in poultry feed is widely applied by feed industry and its capability releasing phytate-bound phosphorus is very well documented. Novel consensus bacterial 6-phytase variant (PHY-G) is newest 6-phytase derived from bacterial phytase gene Buttiauxella sp. expressed in Trichoderma reesei with enhanced functionality for better phytic acids degradation. The present research was conducted to evaluate the efficacy of PHY-G in different doses (1000, 1500 and 2000 FTU/kg) on high phytic acids content diets which at least contained 0.30% Phytate-P. A total 3,675 male broilers Indian River/IR (105 pens, 35 birds/pen) were provided mixed grain diets in seven treatments with fifteen replications, they were divided into two phases of rearing which were starter (1 – 21 d) and finisher (22 – 35 d). Treatments were positive control (PC) using standard diet following IR’s nutrient requirement, negative control 1 (NC1) with nutrient reduction at 0.21 percent unit calcium (Ca), 0.21 percent units available phosphorus (AvP), 0.34 percent unit crude protein (CP) and 66 kcal/kg AME, NC2 with nutrient reduction at 0.23 percent unit Ca & AvP, 0.45 percent unit CP and 75 kcal/kg AME, followed by NC3 with nutrient reduction at 0.24 percent unit Ca & AvP, 0.52 percent unit CP and 79 kcal/kg AME. PHY-G supplementation with dose 1000, 1500 and 2000 FTU/kg on top of NC1, NC2 and NC3 respectively. PHY-G supplementation at any level significantly improved body weight gain/BWG and corrected FCR/McFCR (P<0.05) on starter (1,083 – 1,093 g/bird) and overall phase (2,482 – 2,532 g/bird) compared to any NCs (1,063-1,084 g/bird on starter and 2,387 – 2,398 g/bird on finisher). No significant different were observed on mortality of all treatments but PHY-G supplementation significantly improved (P<0.05) broiler index/BI (444 - 463) versus NCs (427 - 430) and able to maintain it equivalent to PC (455). Toe ash was significantly improved (P<0.05) by all doses of PHY-G (13.28 – 13.56%) compared to NC (12.3 – 12.7%). Apparent ileal digestibility (AID) of Ca was not affected by PHY-G but 1000, 1500 and 2000 FTU/kg PHY-G supplementation significantly improvemed on AID of P (P<0.05) which were 64.97%, 75.60% and 78.29% compared to NCs (42.64%, 48.88% and 46.17% for NC1, NC2 and NC3 respectively). This These data indicated that PHYG supplementation effectively improved broiler growth performance, bone mineralization and P digestibility at any level of dose on high content of phytic acid in the diets.
Keyword: broiler, growth performance, phytase, phytic acid, toe ash