Skeletal muscle growth dynamics and expression of related genes in white and red muscles of rainbow trout fed diets with graded levels of a mixture of plant protein sources as substitutes for fishmeal

Juvenile rainbow trout were fed to visual satiation for 12 weeks with four diets containing fishmeal as the primary protein source (FM diet) or FM substituted with graded levels of a mix of plant proteins to replace 50% (PP50 diet), 75% (PP75) or 100% (PP100) of fishmeal with addition of crystalline amino acids to meet the requirements in indispensable amino acids. Growth performance, feed efficiency and protein efficiency were not affected by 50% fishmeal substitution but all decreased with higher substitution levels (FM = PP50>PP75>PP100). Ammonia excretion was inversely changed with FM substitution level (FM = PP50