Study of fish meal substitution with earthworm in diet of rainbow trout (Oncorhynchus mykiss)

This experiment was carried out to evaluate the effect of earthworm (Eisenia fetida) in diet for rainbow trout in a complete randomized design with 5 treatments in triplicates using 15 cages in a pound for 8 weeks. Ten fish with average weight 120 g was stocked in each replication.The earthworm (as fed) at the levels of 0, 25, 50, 75 and 100% was replaced with fish meal in rainbow trout diet. Results showed that feed intake decreased significantly (P < 0.05) as earthworm increased. The diets contain 25% and 50% earthworm showed no significane differences compared to control for weight gain, specific growth rate and feed conversion ratio (P > b0.05). The chemical composition analysis of fish meat showed that there were no significant effects between control and 25% and 50% earthworm in diet for dry matter, crude protein and ash, but fat content significantly decreaed as earthworm increased (P < 0.05). This present study showed that the earthworm (Eisenia fetida) can be used in rainbow trout diet up to 50% instead of fish meal.