Inclusion effect of jack mackerel meal as feed stimulants in diets replacing different levels of fish meal with various animal protein sources on growth performance of olive flounder (Paralichthys olivaceus)

Abstract

Incorporated feed stimulants into fish feeds is a very sustainable aquaculture technique, especially in developing low FM diet to improve feed consumption and growth performance. This study aims to evaluate inclusion effect of jack mackerel meal (JMM) as feed stimulants in diets replacing different levels of FM with various animal protein sources on the growth, feed utilization, biochemical composition, and non-specific immune response of olive flounder (Paralichthys olivaceus). Two-way [3 substitution source; tuna by-product meal (TBM), chicken by-product meal (CBM), and meat meal (MM) × 2 substitution ratio; 25% and 50%] ANOVA experimental design was applied. Seven experimentally formulated diets were prepared. The control (Con) diet contained 60% FM. Twenty-five and 50% of FM in the Con diet were substituted with TBM, CBM, and MM when 12% JMM was included at the expense of FM, referred to as the TBM25, TBM50, CBM25, CBM50, MM25, and MM50 diets, respectively. All experimental diets were formulated to be isonitrogenous at 56.1% and isolipidic at 10.2%. Four hundred and twenty juvenile fish were randomly distributed into 21 flow-through tanks. Severn experimental diets were assigned to triplicate groups of fish. Both dietary substitution source and ratio had significant (P < 0.0001, P < 0.003, P < 0.0001, P < 0.003, P < 0.0001, and P < 0.0001, respectively) effects on weight gain, specific growth rate (SGR), and feed consumption of fish. Weight gain, SGR, and feed consumption of fish fed the Con diet was significantly (P < 0.0001) inferior to fish fed the TBM25, TBM50, and CBM25 diets. However, no significant (P > 0.05) difference in feed utilization, biochemical composition, and non-specific immune response of fish was observed among the experimental diets. Conclusively, TBM and CBM, and MM could be used as the proper substitutes for FM up to 50%, and 25%, respectively in olive flounder feeds with inclusion of JMM as feed stimulants.