Feed efficiency in the growth of humpback grouper Cromileptes altivelis with prebiotics dietary modulation

Abstract

Energy for fish to carry on with its biological activities and growth comes from food that they eat. In artificial diets, protein become the most expensive source of energy so it is necessary to keep the proportion of protein down to the optimum levels for good growth and feed conversion. In another study, prebiotics resulted in good growth of fish using a manufactured prebiotic supplement. Ideally, we want food material available all year, inexpensive and not be in competition with food material for human consumption. In this study, food formulation with prebiotics made from local products were prepared for fish food. In this study sago was the source of carbohydrates, mackerel and land snails were the source of protein. The formulation was fed to humpback grouper Cromileptes altivelis to study the effectiveness on its growth. Ninety humpback groupers (size 9-9.5 cm, weight 10 – 11 g) were reared in 3 fiberglass tanks for four weeks. Each tank had 30 fish, first tank as control without sago and the two tanks with sago in dietary prebiotic pellet. Length and weight gain were recorded every week then growth performance of fish were assessed in the form of Specific Growth Rate (SGR), Food Conversion Ratio (FCR), weight gain daily and length-weight relationship. Food proximate test were carried out separately in the Integrated Chemistry Laboratory, Institut Pertanian Bogor. Data analysis showed a significant difference in the growth performance of humpback grouper through the values of SGR, FCR and average growth daily, between treatment A and B (with sago) and treatment C (control, zero sago). The proximate test displayed lower protein in treatment A (57.95%) and B (55.95%) but higher in treatment C (59.37%), in the contrary to carbohydrate for treatment A (27.80%), treatment B (26%) and treatment C (22.98%).