Effects of Sustainable Diets containing Fish-Trim Waste, on Growth Performance of Juvenile Sablefish (Anopoploma fimbria)

A feeding trial was conducted to investigate the use of alternative fish feeds produced from fish-trim waste in high plant protein diets for juvenile sablefish (Anopoploma fimbria). Fish meal in the control diet (CD) was replaced in the experimental diets by low molecular weight hydrolysate (LMWH) protein derived from Pacific whiting (Merluccius productus) processing waste, or by Atlantic salmon (Salmo salar) processing trim (ST), which was incorporated into the feed with an experimental heated ball mill. The feeding trial was conducted in an indoor recirculating seawater system and each feed was randomly assigned to triplicate groups of 50 fish (average initial body weight of 57.5 g). The results showed that compared to the control diet, the diets containing LMWH or ST significantly increased feed consumption and fish weight gain. The ST group showed a significantly higher weight gain than the LMWH group. The ST feed, but not the LMWH feed, had a significantly lower feed conversion ratio than the CD feed. The ST feed increased lipid retention efficiency and lipid content in whole body tissue. These results demonstrate that salmon fish trim waste and enzyme hydrolyzed whiting trim in high plant protein diets can increase the performance in sablefish.