Effects of fishmeal quality on growth performance, protein digestibility and trypsin gene expression in pacific white shrimp (Litopenaeus vannamei)

Abstract

Fishmeal quality is of great importance for production of aquatic animals particularly shrimp; however it varies widely depending on raw materials and processing methods. A seven week feeding trial was conducted using five diets to examine effects of fishmeal quality on growth performance, protein digestibility and expression of gene regulating trypsin in Litopenaeus vannamei. Each test diet was fed four times daily to four groups of shrimp with an average initial weight of 2.2 g shrimp-1. The shrimp fed S1-premium grade fish meal (S1-PGFM) diet attained the highest weight gain, specific growth rate with the best feed conversion ratio (FCR) and protein utilization efficiency. Growth of shrimp fed S2-PGFM, grade 1 FM and grade 2 FM containing diets was inferior to those of S1-PGFM fed group. The imported FM diet fed group showed the slowest growth and feed utilization efficiency. FCR of shrimp fed grade 2 FM and imported FM was significantly the poorest (p<0.05). In-vitro protein digestibility using crude enzyme extract from shrimp fed reciprocal diet was not significantly different among treatments but in-vivo protein digestibility of the S1-PGFM fed group was the highest (92.06+0.42%) in concordance with the highest trypsin gene expression.

Keywords

• fishmeal quality
• protein digestibility
• growth
• Litopenaeus vannamei
• trypsin gene