Effects of dietary protein and lipid levels on growth, body composition and nutrient utilization of Channa striata

Very limited information is available on nutrient requirements of Channa striata, particularly during the grow-out stage. A study was carried out to study the requirement and utilization of protein and lipid by Channa striata growing from 31 g to similar to 200 g. Nine experimental diets with graded levels of dietary protein and lipid were formulated using practical ingredients. Increasing dietary crude protein content from 43.4% to 55.6% at 11% dietary lipid content resulted in increases of weight gain, amount of feed consumed, specific growth rate, and thermal-unit growth coefficient. The crude protein requirement of Channa striata was estimated by the saturation kinetics model to be 51.6% dry matter (DM) for growth and 52.1% DM for protein deposition. On the digestible protein basis, the requirement of Channa striata was estimated to be 47.2% DM for growth and 47.8% DM for protein deposition. Increasing lipid content in diets from 7.5% to 23.1% in this study resulted in linear decreases of fish growth and feed intake. Apparently Channa striata cannot tolerate high dietary lipid levels; lipid levels of > 19% DM could negatively affect growth performance. It was also revealed that dietary lipids did not have a protein-sparing effect in Channa striata. Results from this study not only contribute to a better understanding of the nutrient requirement and utilization of Channa striata, but also would be helpful for the development of cost-effective sustainable practical feed formulations for this fish species.