Effects of dietary replacement of fishmeal by yellow mealworm (Tenebrio molitor) larvae meal on growth performance, hematological indices and some of non-specific immune responses of juvenile rainbow trout (Oncorhynchus mykiss)

Abstract

8-week feeding trial was conducted for juvenile rainbow trout (Oncorhynchus mykiss) to determine the optimal amount of Tenebrio molitor meal (TM) that could replace fishmeal in feeds without reducing growth performance, hematological indices and non-specific immune responses. Five isonitrogenous and isolipidic diets were formulated with TM replacing 0% (Control), 25% (TM25), 50% (TM50), 75% (TM75) and 100% (TM100) fishmeal respectively. Each diet was randomly divided into triplicate groups with 20 juveniles (initial weight 10±0.5 g). At the end of the experiment, the mean of the final weight of the fish fed diets with control (41.7±0.7) and diet containing 25% TM powder (43.1±2.1) was significantly higher than other treatments (p0.05). According to a broken-line model, the recommended substituted ratio of TM for fish meal was estimated to be 25% for rainbow trout obtaining maximum weight gain.

Keywords

• Fish meal; Insect meal; Protein replacement; Blood biochemistry; Rainbow trout