Growth Response and Fatty Acid Composition of Channel Catfish Fry Fed Practical Diets Supplemented with Menhaden Fish Oil

Abstract

Abstract A 12-week feeding experiment was conducted to investigate the growth and compositional responses of channel catfish fry (Ictalurus punctatus) fed practical diets containing 7.6% fish meal supplemented with 0, 1.5, 3, or 6% menhaden fish oil. Weight gain significantly improved with increasing levels of supplemental menhaden oil up to 3% of diet; fish fed the diet containing 6% fish oil had depressed weight gain. Whole-body dry matter and lipid increased and protein decreased with increasing levels of menhaden oil. Ash content was not affected by dietary treatment. Fatty acid composition of polar lipids from whole-body tissue showed that supplementation of menhaden fish oil at a rate of 1.5% was sufficient to satisfy the essential fatty acid (EFA) requirement of young channel catfish based on the ratio of 20:3 n-9 to 22:6 n-3 fatty acids. Results from this study indicate that practical diets containing fish meal, but without supplemental fish oil, did not meet the n-3 EFA requirement of young chann...