Actavia 0 Zakes, Z. Przybyl, A. Wozniak, M. Szczepkowski, M. Mazurkiewicz, J. 2004 2004-4-30 156-163 The aim of the experiment was to determine the effect of graded lipid content in experimental isoprotein feed (6, 10, 14% lipids and 45% protein) on the growth performance of juvenile pikeperch (initial body weight P < 0.05). Feed conversion ratio (FCR) and protein efficiency ratio (PER) attained the most advantageous values in this group of fish. The application of the experimental feed had a significant effect on the lipid values in fish bodies and viscera (P < 0.05) although no relationship was detected between the lipid content of the feed and that of the fish muscles. The lipid content was approximately 7.7% in all the experimental groups and the differences between the groups were statistically insignificant (P > 0.05). 4 49