The effect of lysine-supplemented wheat gluten-based diet on yellow perch Perca flavescens (Mitchill) performance

Abstract

Formulation of nutritionally complete and cost efficient diets for yellow perch (Perca flavescens) is a prerequisite for successful intensive culture of this species. One of the objectives of this study was to determine the optimum diet for the grow-out phase of juvenile yellow perch. Fish at the size of 12.9 ± 4 g were individually marked with passive integrated transponders (PIT)-tags and randomly distributed into six 400 L tanks, 45 fish per tank. This experiment included lysine-deficient [(−) Lys] and lysine-supplemented [(+) Lys] wheat-gluten-based diets in triplicate groups. Our experiment showed that the mean weight of fish fed (+) Lys diet (83.9 ± 1.5 g) was significantly larger than fish fed (−) Lys diet (68.6 ± 5.2 g) (P < 0.05). This experiment also showed that the blood plasma concentration of free lysine in (+) Lys group was significantly higher than in (−) Lys group (P < 0.05) and the same trend appeared also in methionine concentrations. The concentration of Lys in deficient group of fish, 3 h after a meal was lower compared with levels of Lys 24 h post-feeding (P < 0.05). Lysine deficiency in diet resulted in significantly higher level of serine, and a similar trend occurred in small and large fish.