Peningkatan kinerja pertumbuhan dan daya tahan tubuh ikan kerapu bebek (Cromileptes altivelis) melalui penambahan selenium dalam pakan

Abstract

This study was conducted to evaluate the effects of different levels and sources of selenium (Se) on the growth performance and viability of juvenile humpback grouper (Cromileptes altivelis). The experiments were arranged and conducted in four stages. The first experiment was conducted to compare the digestibility of dietary Se from sodium selenite and selenometionin. Two groups of grouper were given the experimental diets for 14 days. The result of this experiment showed that selenometionin was more digestible (68,68%) than sodium selenite (60,36%). In experiment 2, two different sources of Se at varying concentrations were added to the basal diet (sodium selenite at 0,5; 1; 2; and 4 mg Se/kg diet, and selenometionin at 1; 2; and 4 mg Se/kg diet, respectively). Another treatment was unsupplemented Se. Of the treatments, selenometionin supplementation with dose of 4 mg Se/kg diet showed a better performance than other diets. The addition of sodium selenite with dose of 0,5 mg Se/kg diet showed a toxic effects. In experiment 3, pelleted diets with 0; 0,025; 0,05; 0,1; 0,2; and 0,4 mg Se/kg diet from sodium selenite were used to fed triplicate groups of fish twice a day at satiation (mean initial length and weight: 5,83+0,28 cm and 3,47+0,43 g, respectively) in a 90x40x35 cm aquaria. The experimental fish were reared for 42 days at a density of 15 ind./aquarium. At the end of the experiment, fish were dipped in fresh water for 10 minutes and no aeration was added. The addition of sodium selenite with dose of 0,05 mg Se/kg diet enhanced growth performance and viability of juvenile humpback grouper. The last experiment was conducted to evaluate the effects of different levels of selenometionin on the growth and viability of juvenile humpback grouper. In this experiment, pelleted diets with 0; 4; and 16 mg Se/kg diet from selenometionin were used to fed triplicate groups of fish twice a day at satiation. The experimental fish were reared for 42 days at a density of 15 ind./aquarium. At the end of the rearing period, fish were transported for 13 hours and then reared again for 20 days. At the second week of the continued rearing period, fish were dipped in fresh water for 10 minutes and no aeration was added. The studies showed that the addition of selenometionin at a concentration of 4 mg Se/kg diet enhanced growth performance and viability of juvenile humpback grouper.