ZAMJENA RIBLJEG BRAŠNA S ORGANSKIM PROTEINOM NA BAZI KVASCA U HRANI ZA PACIFIČKE BIJELE RAČIĆE (Litopenaeus vannamei): LABORATORIJSKI I PRIRODNI UVJETI

The feasibility of totally replacing the fishmeal component of marine shrimp (Litopenaeus vannamei) diets was examined both in the laboratory setting and during a full–scale commercial trial. Animals were fed either a traditional fishmeal–based diet or one in which complete replacement of fishmeal, on a per protein basis, was manufactured using a yeast–based product, NuPro®. Laboratory studies determined that irrespective of diet fed, no difference in shrimp performance (weight gain, survival and SGR) occurred. A field trial was thus activated to determine whether lab–scale studies were transferable to the commercial setting. Trials were conducted in earthen ponds from mid–June to early November 2005. Ponds were initially stocked with PL12–16 shrimp at a rate of 100,000 per hectare. At trial end, ponds receiving the NuPro®–based feed had equivalent growth to that of shrimp fed the traditional, fishmeal–based diet. Percent increase in weight from initial values and survival for the NuPro® ponds was 296, 269 and 275%, and 78, 76 and 85% respectively, whereas that for the fishmeal–based diet was 305% and 80% respectively. Noteworthy was that within pond size variation of L. vannamei was lower in NuPro® fed animals (±2.3 g) when compared against animals receiving the traditional feed (±4.1 g). Overall observations from the field trial indicate the importance of the »bioreactor« pond with respect to the supply of energy to sustain shrimp growth potential.