Effect of Dietary Lipids on Growth, Feed Utilization, and Protein Sparing in Black Rockfish, Sebastes schlegeli

Abstract

The effects of dietary lipids on growth and feed utilization of juvenile black rockfish (Sebastes schlegeli) were examined. Triplicate groups of 20 juveniles were fed diets containing 42% crude protein, supplemented with 0%, 3%, 6%, 9% and 12% lipid (% dry matter) for 60 days. At the end of the experiment, survival rate of all groups was at least 88%. Fish fed the diet containing 6% lipids had a significantly (P < 0.05) higher growth rate, better feed conversion and protein efficiency ratios than the other groups. Muscle lipids increased dramatically as the dietary lipid level increased; the highest lipid content was obtained in fish fed the highest lipid diet. Conversely, muscle protein declined as the dietary lipid level increased, and the lowest protein value was in fish fed the 12% lipid diet. Ash and dry matter content did not significantly differ between groups. Increasing the lipid level to 6% was most effective for improving fish growth and feed efficiency.