POTENTIAL USE OF Ulva lactuca AS FEED INGREDIENT FOR TILAPIA

Abstract

Due to the mainly imported for fish feed ingredients in Indonesia, many attemps have been made to discover local potential ingredients to reduce the utilization of imported ingredients. In this experiment, the utilization of Ulva lactuca as feed ingredient for tilapia was evaluated. Experiment 1 was conducted to determine the digestibility of Ulva for tilapia. In experiment 2 and 3, Ulva was used to substitute wheat pollard of either 0, 3, 6, 9, or 12 % in the feed formulation. In experiment 2, fish with an average body weight of 4.1±0.15 g were fed on those diets, and were cultured for 55 days. To calculate the digestibity in experiment 3, Cr 2 O 3 was added into the diet of exeriment 2; then fed on the fish with an average body weight of 19.0±0.67 g. Results showed that apparent digestibility of dry matter and crude protein of Ulva were 66.3 and 83 %, respectively. Ash content in the diet increased of 13.5% with Ulva inclusion of 12%. On the other hand, using Ulva as a substitute for pollard up to 12% was not affected the growth performance of fish. Regardless of the Ulva level in the diet, the digestibility of the diet was the same. Therefore, Ulva is a potential source of local feed ingredient for tilapia. ABSTRAKUntuk mengurangi ketergantungan bahan baku pakan impor, telah dilakukan penelitian untuk mengetahui potensi rumput laut Ulva lactuca sebagai bahan baku pakan ikan nila. Penelitian tahap 1 adalah mengevaluasi kecernaan Ulva di ikan nila. Di dalam penelitian tahap 2 dan 3, Ulva ditambahkan ke dalam formulasi sebanyak 0, 3, 6, 9, dan 12 % untuk mengganti pollard. Di penelitian 2, pakan diberikan ke ikan nila ukuran 4,1±0,15 g selama 55 hari, lalu diukur kinerja pertumbuhannya. Sedangkan di penelitian 3, pakan penelitian 2 ditambah Cr 2 O 3 , lalu diberikan ke ikan ukuran 19,0±0,67 g untuk uji kecernaan pakan. Hasil penelitian menunjukkan bahwa Ulva memiliki kecernaan total dan protein yang tinggi, masing-masing 66,3 dan 83,0 %. Peningkatan jumlah Ulva di dalam formulasi pakan meningkatkan kadar abu pakan, sehingga pada penambahan Ulva 12 %, kadar abu pakan mencapai 13,5 %. Namun demikian, penggunaan Ulva sebagai pengganti pollard sampai 12 % tidak menurunkan kinerja pertumbuhan ikan nila. Penggunaan Ulva sebagai bahan baku pakan ikan nila juga tidak menurunkan kecernaan pakan tersebut. Oleh karena itu bisa disimpulkan bahwa Ulva sangat potensial untuk digunakan sebagai bahan baku pakan ikan nila.Kata kunci: Ulva lactuca, ikan nila, kecernaan, pertumbuhan

Evaluation of seaweed, Ulva lactuca as a fresh diet for nursery stage of golden rabbitfish, Siganus guttatus

“…According to these, the ash content of dry Ulva was higher than the optimal range, which could cause the fish to be unable to digest the diet optimally. Consumption of a diet with high ash content will absorb low nutrients due to decreased diet digestibility, impacting fish growth [33]. Likewise, ash in the diet does not contain energy, even though the ash component contains micro and macro minerals needed for fish metabolism [34].…”