Assessment of open‐source fish‐free feeds ( F3 ) for pompano, Trachinotus carolinus (Perciformes, Carangidae), under hyposaline conditions

Abstract

Florida pompanos (15.3 g initial average weight) were fed one of seven open-source experimental diets to examine the effects of the complete removal of fishmeal (FM) and fish oil (FO) upon growth over a 12-week period. Diets were compared against an investigational feed containing FM and FO. Three different oils, derived from flax, canola and an alga, alone or in combination, were evaluated as alternatives for FO. FM was replaced in the experimental diets using a blend of proteins that included poultry by-product meal, hydrolysed soy and soy and corn protein concentrates. The study was undertaken in a recirculating aquaculture system and under hyposaline (3 g/L) conditions with each diet being examined in triplicate. At trial end, fish fed some diets increased their initial body weight by over 300%, and there were no differences (p > 0.05) between diets for feed efficiency, condition or K-factor, whole-body composition, intraperitoneal fat (%), hepatosomatic index or fillet yield (%). All experimental diets achieved parity with the FM/FO control feed. Differences were detected in fillet fatty acids among diets, with the latter corresponding to dietary profiles. This study represents the first with pompano to evaluate diets simultaneously void of FM and FO and provides strong evidence to support the practicability of removing FM/FO from pompano diets.