Use of Fish Hydrolysates and Fish Meal Byproducts of the Alaskan Fishing Industry in Diets for Pacific White Shrimp Litopenaeus vannamei

Abstract We determined the suitability of four fish hydrolysates and two fish meals (Pacific halibut Hippoglossus stenolepus and arrowtooth flounder Atheresthes stomias; all derived from byproducts of the Alaskan fishing industry) as replacements for menhaden fish meal in shrimp diets. A control diet (30% crude protein; 8.5% crude lipid) was produced with menhaden meal (13% of diet). Experimental diets were manufactured by using each hydrolysate or fish meal to replace 50% of the menhaden meal on an isonitrogenous basis. Each diet was fed to Pacific white shrimp Litopenaeus vannamei in an outdoor, zero-water-exchange system for 8 weeks. Final weight, survival, feed efficiency, and growth rate were compared among treatments by analysis of variance. The final weights and growth of Pacific white shrimp fed two of the hydrolysates (one acidified to pH 3.8 and left in a liquid state; the other acidified, then neutralized to pH 6.5 and drum-dried) and the two fish meals were not different from those of shrimp fed the control diet. Shrimp that were given the other two hydrolysates (one acidified to pH 3.8 and then drum-dried; the other hydrolyzed [but not acidified] and then drum-dried) had lower final weights and growth than shrimp fed the control diet. These data indicate that the two fish meals and two of the hydrolysates in this trial can replace 50% of menhaden meal in diets for shrimp, although there is some loss of growth potential in some cases. The lack of a diet effect on feed efficiency indicates that the growth differences were mostly the result of differences in feed intake rather than nutritional quality.