fa <span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">The effects dietary supplementation with <em>Aloe vera </em>extract (AE) on the immunity responses and hematological parameters of rainbow trout </span></span><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">(<em>Oncorhynchus mykiss</em>) fry were evaluated </span>in eight weeks trial. 600 rainbow trout (<em>O. mykiss</em>) fry with an average </span>initial body weight of 13&plusmn;0.05g <span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">were randomly allocated into two treatment groups including placebo-treated group (control) and </span></span><em><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">A. vera </span></span></em><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">extract-treated group, each with three replicates. </span></span><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">The fish were hand-fed once a day with diet medicated AE or placebo (70 % lactose, 10 % starch and 20 % talc) at a rate of 1% of feed weight in the first feeding for 8 weeks. At the end of the identical every two weeks (2, 4, 6, and 8 weeks) 24 h after feeding, some of immunological and hematological parameters were analyzed. The results showed that </span></span><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">serum total protein, albumin and globulin, respiratory burst activity, phagocytic activity and serum lysozyme activity vary among the two treatment groups which were found to be higher in the AE-treated group (<em>p</em><0.05). However, there were no significant differences in none of hematological parameters between two groups. It was concluded that supplementation of AE at a rate of 1% in feed registered higher immunological responses in compared to placebo group. Therefore, supplementation of AE in fish diet would enhance the immunity responses in fish. It may use in fish diets particularly at time of outbreaks.&nbsp; &nbsp;</span></span> Immune responses, Aloe vera, Oncorhynchus mykiss, Herbal medicine 884 896 http://jifro.ir/browse.php?a_code=A-10-870-2&slc_lang=fa&sid=1 M. Haghighi masoud126@yahoo.com 100319475328460022513 100319475328460022513 Yes M. Sharif Rohani 100319475328460022514 100319475328460022514 No H. Pourmoghim 100319475328460022515 100319475328460022515 No M. Samadi 100319475328460022516 100319475328460022516 No M. Tavoli 100319475328460022517 100319475328460022517 No M. Eslami 100319475328460022518 100319475328460022518 No R. Yusefi 100319475328460022519 100319475328460022519 No