A Purified Test Diet for Coho Salmon, Oncorhynchus kisutch, Fry

Abstract

After amino acid analyses, A/E ratios of coho salmon, Oncorhynchus kisutch, fry and the feedstuffs used were computed, and the essential amino acid pattern of coho salmon fry was used as a reference pattern. The essential amino acid pattern of the diets composed of casein as a sole protein source was simulated to those of the reference pattern by supplementing amino acids. The supplemental effect of amino acids on the growth was examined in a six-week feeding trial using diets with three different protein levels and fish meal diet as a control. The poorest growth was observed in the fish fed casein diet (40% protein) without amino acid supplementation. Much better growth and feed effciency were obtained in groups fed with the diets of amino acids supplementation comparable to those of the fish meal diet. Among these treatments, the fish fed with the low protein diet (33% protein) showed the same growth rate as a 40% protein casein diet.