Replacement of fishmeal with soybean meal and mineral supplements in diets of Litopenaeus vannamei reared in low-salinity water

Abstract

To date, few studies have examined the impacts of the mineral profiles of diets high in plant protein on shrimp in aquaculture. Therefore, a feeding trial was conducted to determine how the mineral levels of diets formulated with soybean meal replacement of fishmeal affected the growth performance, osmoregulation and tissue mineralization of Litopenaeus vannamei at low salinity. Six diets were designed: two high fishmeal diets (FMN and FMR) contained 300g/kg fishmeal, and four high soybean meal diets (SBN, SBF, SBR and SBRR) were formulated by soybean meal replacement of 60% fishmeal of FMN with various mineral supplements; FMN and SBN had no mineral supplements; SBF was supplemented with minerals according to the mineral composition of FMN; FMR and SBR with mineral supplements were based on dietary requirements of L. vannamei; SBRR had the same macro-element level as SBR but double micro-element content. After an 8-week feeding trial, the growth performance, serum osmotic pressure, gill ATPase activity and tissue mineralization of Ca and P of shrimp were significantly negatively affected by the replacement of fishmeal with soybean meal. With proper mineral supplementation, however, the growth performance, muscle protein and lipid deposition, and osmoregulation of shrimp fed diets high in soybean meal were markedly improved. Additionally, shrimp fed high soybean protein diets with supplementation of relevant minerals had similar tissue mineralization to those fed high fishmeal diets. Anyhow, there were no significant differences in experiment indexes between the shrimp fed the FMN and FMR diets, nor between the shrimp fed the SBR and SBRR diets. In conclusion, high soybean meal diets need to be supplemented with appropriate minerals to compensate for the negative effects of their mineral composition on L. vannamei reared in low-salinity water. Statement of relevanceNo competing interests exist in commercial aquaculture.