en aquaculture aquaculture كاربردي Orginal research papers <span lang="TR" style="font-size:10.5pt"><span calibri="" style="font-family:">The</span></span><b> </b><span lang="TR" style="font-size:10.5pt"><span calibri="" style="font-family:">present study was conducted to evaluate the effects of three different dietary microalgae on growth, intestinal histology, immune biomarkers, and resistance to a bacterial pathogen</span></span><span lang="TR" style="font-size:10.5pt"><span calibri="" style="font-family:"> (<i>Vibrio anguillarum</i>)</span></span><span lang="TR" style="font-size:10.5pt"><span calibri="" style="font-family:"> in juvenile rainbow trout, <i>Oncorhynchus mykiss</i>. Four experimental diets were prepared, including a basal diet (CON) and three diets containing <i>Chlorella</i> sp. (CHL), <i>Haematococcus</i> sp. (HAE), or <i>Schizochytrium</i> sp. (SCH), at 0.5% for each microalga which was supplemented in the basal diet. A total of 180 juvenile rainbow trout with an initial body weight of 12.16</span></span><span lang="TR" style="font-size:10.5pt"><span calibri="" style="font-family:">&plusmn;0.01 g (mean&plusmn;SD) were randomly distributed into 12 tanks and reared by the semi-recirculation system. After six weeks of the feeding trial, the weight gain (99.4%), specific growth rate (1.92%/day), and myeloperoxidase activity (5.08), of the fish fed the HAE were significantly higher than those of fish fed the other diets (<i>p</i><0.05). The intestinal villus length of the fish fed the HAE diet (1.34 &micro;m) was significantly higher than that of those fed<i> </i>the<i> </i>CHL (1.13 &micro;m) and CON (1.14 &micro;m) diets. The cumulative survival rates (CSR) were recorded for 27 days after intraperitoneal injection of the bacterial pathogen <i>V. anguillarum</i>. The CSR of the fish fed the HAE diet (75%) was significantly higher than that of those fed the other diets. It is suggested that <i>Haematococcus</i> sp. (0.5% inclusion in the diet) may improve weight gain, specific growth rate, intestinal villus length, and myeloperoxidase activity as well as increase the survival rate of juvenile rainbow trout against the <i>V. anguillarum</i> challenge.</span></span> Rainbow trout, Microalgae feed additives, Vibrio anguillarum, Immune biomarkers 537 557 http://jifro.ir/browse.php?a_code=A-10-4775-1&slc_lang=en&sid=1 D. Aulia damursalin@gmail.com 100319475328460052556 100319475328460052556 No Major of Aquaculture and Applied Life Sciences, Division of Fisheries Life Sciences, Pukyong National University C.J. Rivero cjo@cientifica.edu.pe 100319475328460052557 100319475328460052557 No Universidad Científica del Sur W. Choi thm622@naver.com 100319475328460052558 100319475328460052558 No CJ Feed & Care A. Hamidoghli alihamid@pukyong.ac.kr 100319475328460052559 100319475328460052559 No Aquaculture Research Institute, University of Idaho J. Bae bjh2921@naver.com 100319475328460052560 100319475328460052560 No Aquafeed Research Center, National Institute of Fisheries Science S. Hwang syhser27@pukyong.ac.kr 100319475328460052561 100319475328460052561 No Major of Aquaculture and Applied Life Sciences, Division of Fisheries Life Sciences, Pukyong National University D.H. Kim doho3206@fira.or.kr 100319475328460052562 100319475328460052562 No East Sea Branch, Korea Fisheries Resources Agency S. Lee shlee@pknu.ac.kr 100319475328460052563 100319475328460052563 Yes Major of Aquaculture and Applied Life Sciences, Division of Fisheries Life Sciences, Pukyong National University S.C. Bai scbai@pknu.ac.kr 100319475328460052564 100319475328460052564 No Feeds and Foods Nutrition Research Center, Pukyong National University