fa Biology & physiology Biology & physiology پژوهشي Orginal research papers <p dir="ltr" style="text-align: justify;">This study was designed to determine the technical and economic efficiency levels of the commercial basal feeds enriched with 10%, 5% and 0% rates of LNA (LNA10, LNA5<em> and </em>LNA0) on the growth performance of brown trout by analyzing the marginal factor cost (MFC) and the marginal revenue of physical product (MRPP). A total of 300 brown trout with an initial individual weight of 4&plusmn;0.05 g were randomly divided in 12 cages (25 fingerlings in each cage), and kept under 24L:0D (light/dark) photoperiod condition for 9 weeks treated by LNA10<em>, LNA5</em> and <em>LNA0</em>. The results of the study showed that LNA0 and LNA10 of the effective feed sources, respectively on the growth performance of brown trout were more suitable to produce as the homogeneous products for the consumers and differentiated those for the drug industry in view of the economic and technical efficiencies.&nbsp;</p> 913 926 http://jifro.ir/browse.php?a_code=A-10-1272-204&slc_lang=fa&sid=1 Y. Topcu : ytopcu25@hotmail.com 100319475328460016283 100319475328460016283 Yes H. Arslan 100319475328460016284 100319475328460016284 No