Attempts to increase the growth rhythm of juvenile Northern pike (Esox lucius, L.) by adding enzyme based ingredients into dry feed

Northern pike’s rearing in recirculation systems is limited because of increasing FCR togetherwith size of fish. The reason is apparently connected to the disability of pike to secrete sufficientdigestive enzymes to process any offered dry feed. During feeding on natural food, the pike gets thenecessary enzymes from the prey’s body. This is the reason why we added to feeds digestive enzymesand even “fish juice”. We used commercially available enzymes such as Colebil and Triferment indifferent dozes. We also used supplements of live feed. The results are encouraging since we noticed ahigher growth rate in feeding the pikes fingerlings with dry feed enriched with protease enzymes.