Preliminary study of rubber seed Hevea brasiliensis oil utilization for tilapia diet

ABSTRACT This research was conducted as a preliminary study on utilization of RBO for Nile tilapia (Oreochromis sp.) diet by also evaluating its effect on growth the performance. This research used SULTANA strain at average initial body weights of 8.33±0.07 g/ind. Experimental design was set in completely randomized design. Each treatment was done in triplicates. The treatments were various additions of RBO to replace corn oil in the diet, which were 0%, 25%, 50%, 75%, and 100%. Feeding rate, feed efficiency, protein retention, fat retention, specific growth rate, glucose, cholesterol, triglycerides, HDL (high-density lipoprotein), and hematology were used as evaluating parameters. The results showed that the growth performance, blood chemistry and hematology of fish decreased as the increasing of RBO level in the diet. These are caused by feed intake decreased significantly, which were 583.5 g to 145.6 g of treatments 0% to 100% RBO. Blood glucose, haemoglobin and specific growth of fish in the treatment of 0–100% RBO were 48.7–22.2 mg/dL, 7.6–5.4%, and 3.5–0.8%, respectively. The lowest survival was observed in fish fed 100% RBO (66.7%). Fish growth performance of 0% RBO was the best, so RBO could not be utilized yet as a source of fatty acid or corn oil replacement in tilapia diet. Keywords: free radical, HCN, Oreochromis sp., rubber seed oil ABSTRAK Penelitian ini dilakukan sebagai studi awal pemanfaatan minyak biji karet (MBK) untuk pakan ikan nila dan mengevaluasi pengaruhnya terhadap pertumbuhan ikan nila. Ikan uji yang digunakan adalah ikan nila strain SULTANA dengan bobot awal rata-rata 8,33±0,07 g/ind. Penelitian didesain dalam rancangan acak lengkap (RAL) dengan lima perlakuan dan tiga ulangan. Perlakuan yang diuji berbagai sumbangan MBK untuk mengganti minyak jagung dalam pakan, yaitu 0%, 25%, 50%, 75%, dan 100%. Selama pemeliharaan, beberapa parameter yang diukur adalah jumlah konsumsi pakan, efisiensi pakan, retensi protein, retensi lemak, laju pertumbuhan spesifik, glukosa, kolesterol, trigliserida, high-density lipoprotein (HDL), dan gambaran darah. Hasil penelitian ini menunjukkan bahwa kinerja pertumbuhan, kimia darah dan gambaran darah ikan semakin menurun seiring dengan penambahan MBK dalam pakan. Hal ini disebabkan semakin menurunnya jumlah konsumsi pakan secara signifikan, yaitu 583,5 g menjadi 145,7 g dari perlakuan 0% ke 100% MBK. Glukosa darah, hemoglobin dan laju pertumbuhan spesifik ikan pada perlakuan 0–100% MBK masing-masing adalah 48,7–22,2 mg/dL, 7,6–5,4% dan 3,5–0,8%. Sintasan ikan terendah terjadi pada perlakuan 100% MBK, yaitu 66,7%. Kinerja pertumbuhan pada perlakuan 0% MBK adalah yang paling baik sehingga MBK belum dapat dimanfaatkan sebagai sumber lemak menggantikan minyak jagung pada pakan ikan nila. Kata kunci: radikal bebas, HCN, Oreochromis sp., minyak biji karet