Sri Nuryati

Immune response and disease resistance of shrimp fed biofloc grown on different carbon sources

The objective of this study was to document the immunological effects of growing shrimp in biofloc systems. The experiment consisted of four types of biofloc systems in which bioflocs were produced by daily supplementation of four different carbon sources, i.e. molasses, tapioca, tapioca-by-product, and rice bran, at an estimated C/N ratio of 15 and a control system without any organic carbon addition. Each biofloc system was stocked with Pacific white shrimp (Litopenaeus vannamei) juveniles that were reared for 49 days. The use of tapioca-by-product resulted in a higher survival (93%) of the shrimp as compared to the other carbon sources and the control. The highest yield and protein assimilation was observed when tapioca was used as the carbon source. After 49 days, phenoloxidase (PO) activity of the shrimp grown in all biofloc systems was higher than that of the shrimp from the control system. Following a challenge test by injection with infectious myonecrosis virus (IMNV), the levels of PO and respiratory burst (RB) activity in the shrimp of all biofloc treatments were higher than that of the challenged shrimp from the control treatment. An increased immunity was also suggested by the survival of the challenged shrimp from the experimental biofloc groups that was significantly higher as compared to the challenged shrimp from the control treatment, regardless of the organic carbon source used to grow the bioflocs. Overall, this study demonstrated that the application of biofloc technology may contribute to the robustness of cultured shrimp by immunostimulation and that this effect is independent of the type of carbon source used to grow the flocs.

The growth and physiological responses of tambaqui Colossoma macropomum fed on the high dose of clove oil-supplemented diet

ABSTRACT In this study, tambaqui Colossoma macropomum juvenile were given feed supplemented with clove oil Syzygium aromaticum at a dose of 0 and 100 mg/100 g diet. This study purposed to assessment the effect of clove oil supplementation at high dose (100 mg/100 g diet) on growth performance and health status of freshwater tambaqui. As many as 25 fishes with initial body weight 7.62±0.44 g maintained in 15 aquariums for 45 days. Each treatment consisted of three replications. Data were analyzed by t-test. The results showed that tambaqui growth performance on both treatments were not significantly different. However, supplementation of high doses 100 mg clove oil/100 g diet showed reduce on the blood parameters and declining the abundant of intestinal microflora in tambaqui gut, but the types seen more diverse. The observation of fish liver histology showed that hepatocyte cells in the treatment of 100 mg clove oil become smaller and dense compared with 0 mg clove oil treatment. The use of high doses of clove oil does not interfere with the tambaqui growth performance despite the downturn in the physiological responses were observed. Keywords: clove oil, Syzygium aromaticum , Colossoma macropomum , growth performance ABSTRAK Di dalam penelitian ini, benih ikan bawal tawar Colossoma macropomum dipelihara dengan pemberian pakan yang ditambah minyak cengkeh Syzygium aromaticum pada kadar 0 dan 100 mg/100 g pakan. Tujuannya untuk melihat pengaruh penambahan minyak cengkeh di dalam pakan pada dosis tinggi (100 mg/100 g pakan) terhadap performa pertumbuhan dan respons fisiologis ikan bawal. Sebanyak 25 ekor ikan bawal dengan bobot individu awal 7,62 ± 0,44 g dipelihara pada 15 akuarium selama 45 hari. Data yang diperoleh dianalisis dengan uji komparasi t-test antar dua perlakuan dengan tiga ulangan. Hasil penelitian menunjukkan bahwa tidak ada pengaruh dari kedua perlakuan terhadap parameter pertumbuhan. Namun, pemberian pakan yang mengandung minyak cengkeh dosis tinggi 100 mg/100 g pakan mempengaruhi respons fisiologis berupa rendahnya kisaran nilai gambaran darah serta menurunnya jumlah mikroflora di usus ikan bawal, meski jenisnya lebih beragam. Hasil pengamatan histologi hati ikan pada perlakuan 100 mg minyak cengkeh menunjukkan bahwa sel hepatosit berukuran lebih kecil dan terlihat rapat dibandingkan dengan perlakuan 0 mg minyak cengkeh. Penggunaan minyak cengkeh dosis tinggi tidak menganggu performa pertumbuhan ikan bawal meskipun terjadi penurunan pada respons fisiologis yang diamati. Kata penting: minyak cengkeh, Syzygium aromaticum , Colossoma macropomum , performa pertumbuhan