Fish protein hydrolyzate in starter diets for Atlantic salmon (Salmo salar) fry

Triplicate groups of Atlantic salmon fry with an initial weight of 0.15 g were fed four experimental diets for 20 weeks. The diets were: a commercial steam pelleted salmon starter (Diet 1); a Norse-LT 94(R) fish-meal based control diet (Diet 2); 5% of amino acid nitrogen in Diet 2 replaced by amino acid nitrogen from fish protein hydrolyzate (Diet 3); 8% of amino acid nitrogen in Diet 2 replaced by amino acid nitrogen from fish protein hydrolyzate (Diet 4). The growth rate and the final weight of fish fed Diets 3 and 4 were higher (P < 0.05) than that of fish fed Diet 2 at 20 weeks. Diet 1 was at the same level as Diets 3 and 4. The results indicated a positive effect on growth of juvenile salmon by replacing 5 or 8% of the amino acid nitrogen in a LT fish-meal based diet with amino acid nitrogen from fish protein hydrolyzate. The were no differences in mortality, condition factor, liver to body weight or gut to body weight ratios which could be related to the diets.