IN-VITRO PROTEIN-SYNTHESIS IN MUSCLE OF ATLANTIC SALMON (SALMO-SALAR)AS AFFECTED BY THE DEGREE OF PROTEOLYSIS IN FEEDS

Atlantic salmon (Salmo salar) were fed three diets of freeze dried cod muscle to study the effect of pre-digestion upon growth and protein s ynthesis. Two of the cod muscle samples had different degrees of pepsi n pre-digestion. Specific growth rates, but not the feed conversion, d ecreased in salmon fed the most hydrolyzed feed. Apparent digestibilit ies were high, and did not differ between dietary treatments. The capa city of protein synthesis in liver and white trunk muscle tissues did not differ significant between feeding groups when judged by the ribos omal-RNA/DNA ratio. Protein synthesis determined in vitro in isolated ribosomes from white trunk muscle, however, showed a significantly hig her rate of synthesis for those fish fed the nonproteolysed feed. This probably was due to differences in the polyribosome profiles in the w hite trunk muscle.