The performances of hybrid grouper, Epinephelus fuscoguttatus × E. lanceolatus fed with defatted soybean meal-based feeds with supplementation of phytase

Fish meal is the primary protein ingredient in fish feed and this material is expensive and non-renewable. However, the use of plant protein in marine fish feed such as soybean meal products are limited due to anti-nutritional factor that hindered fish performances. Therefore, hybrid grouper, a cross between tiger grouper (Epinephelus fuscoguttatus) and giant grouper (E. lanceolatus) was evaluated using defatted soybean meal (DSM) based feed and phytase. DSM- based feeds (30% of protein replacement) with supplementation of phytase at 0 and 2000 FTU/kg dosages, as well as a control feed (CON) comprised completely of fish meal (FM) was given to the hybrid grouper with an initial body weight of 6.2±0.0g. Each experimental feed was formulated with 50% of crude protein and 12% of crude lipid. The fish were raised in 100L fiberglass tanks equipped with a flow-through water system for each triplicate treatment. The hybrid grouper was fed with the respective feeds twice a day until the perceived satiation level for 12 weeks. Hybrid grouper fed CON and DSM-based feed did not exhibit any significant difference in growth. However, hybrid grouper fed with DSM-based feed grew larger compared to that fed with CON. Hybrid grouper fed with DSM-based feed showed significantly higher feed intake, lower net protein utilization, hepatosomatic index, viscerosomatic index, and apparent digestibility coefficient (ADC) protein values (p