Developing a low fishmeal diet for juvenile Pacific white shrimp, Litopenaeus vannamei, using the nutritional value of FM as the reference profile

An 8-week feeding trial was conducted to evaluate the effect of fish-meal replacement on growth performance, antioxidative ability, immune capacity and haemolymph metabolites of Litopenaeus vannamei . A 250 g/kg fish-meal diet was used as control (Diet 1). Other two diets contained 100 g/kg fishmeal, Diet 2 was supplemented with three indispensable amino acids, and Diet 3 was supplemented with microbalance components and phytase. Weight gain was lower in shrimp fed the Diet 2 than shrimp fed the Diet 1. Feed efficiency, protein efficiency ratio and survival were higher in shrimp fed the Diet 1 than other groups. Glutathione and nitric oxide contents in haemolymph were decreased in shrimp fed the Diet 2, and nitric oxide synthetase, phenoloxidase, acid phosphatase and myeloperoxidase activities showed the similar tendency. In hepatopancreas, antioxidative ability and immune capacity also lower in shrimp fed the Diet 2. In haemolymph, 21 differential metabolites were identified, and 13 metabolism pathways were affected by different diets. Generally, the fishmeal inclusion level could be reduced from 250 g/kg to 100 g/kg without affecting the growth performance of L. vannamei , and meanwhile, the protein utilization efficiency and antioxidative ability of shrimp fed the low fishmeal diets should be more focused on in future studies.