Performance of Juvenile Coho Salmon Oncorhynchus kisutch Fed Diets Containing Meals from Fish Wastes, Deboned Fish Wastes, or Skin‐and‐Bone By‐Product as the Protein Ingredient

Abstract

AbstractThe suitability of meals derived from fish processing wastes as the protein fraction in practical diets for hatchery‐reared coho salmon was investigated. The study compared the performance of coho salmon fed diets containing three products: a skin‐and‐bone meal (SB), a deboned meal (DM), and a whole‐fish meal (WM) made directly from the fish wastes. A commercial trout diet (CO) was fed to a fourth treatment group. Diets were fed at 3% of body weight per day to juvenile coho salmon for 12 wk. Survival (> 94%) was not significantly different among treatment groups. Average fish weight, feed conversion ratio, whole body proximate and mineral composition, and protein and phosphorus retention were compared. There were no significant differences after 12 wk of feeding in fish weight between WM, DM, and CO, but SB had significantly lower weight and whole body lipid, and significantly higher ash. Compared to WM, DM had a significantly lower feed conversion ratio and higher retention of protein and phosphorus, but these indices were not significantly different from CO. It is concluded that DM is a potentially superior protein ingredient compared to WM, while specific characteristics of SB will limit its use as a protein source in feeds for salmonids. However, SB may prove to be a suitable mineral supplement when added at a low level. Utilization of fish processing wastes in salmonid diets could be a commercially viable alternative to direct disposal of processing wastes.