title: Effects of dietary fructooligosaccharide levels and feeding modes on growth, immune responses, antioxidant capability and disease resistance of blunt snout bream (Megalobrama amblycephala).
abstract: This study aimed to determine the effects of fructooligosaccharide (FOS) levels and its feeding modes on growth, immune response, antioxidant capability and disease resistance of blunt snout bream (Megalobrama amblycephala). Fish (12.5 ± 0.5 g) were subjected to three FOS levels (0, 0.4% and 0.8%) and two feeding modes (supplementing FOS continuously and supplementing FOS two days interval 5 days) according to a 3 × 2 factorial design. At the end of 8-week feeding trial, fish were challenged by Aeromonas hydrophila with concentration of 1 × 10(5) CFU mL(-1) and mortality was recorded for the next 96 h. Fish fed 0.4% FOS continuously (D2) and fish fed the basal diet for 5 days followed by 0.8% FOS for 2 days (D5) showed admirable growth performance. The highest plasma lysozyme, acid phosphatase and myeloperoxidase activities as well as complement component 3, total protein and immunoglobulin M (IgM) levels were all observed in fish fed D5. They were significantly higher (P < 0.05) than those of the control group and/or fish fed 0.8% FOS continuously, but exhibited no statistical difference (P > 0.05) with that of fish fed D2. A similar trend was also observed in antioxidant capability as well as the expression of Leap-I and Leap-Ⅱ. Mortality showed an opposite trend with the immune response with the lowest rate observed in fish fed D5. The results indicated that diet supplementing FOS in appropriate levels and feeding modes could improve the growth, immune response and antioxidant capability of fish, as might consequently lead to enhanced disease resistance. It can be speculated that the basal diet for 5 days followed by 0.8% FOS for 2 days was most suitable for blunt snout bream.
authors.affiliation: Key Laboratory of Aquatic Nutrition and Feed Science of Jiangsu Province, College of Animal Science and Technology, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing 210095, People's Republic of China. Electronic address: zhangchunnuan12@163.com.
authors.forename: Chun-Nuan
authors.initials: CN
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Aquatic Nutrition and Feed Science of Jiangsu Province, College of Animal Science and Technology, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing 210095, People's Republic of China.
authors.forename: Xiang-Fei
authors.initials: XF
authors.lastname: Li
authors.affiliation: Key Laboratory of Aquatic Nutrition and Feed Science of Jiangsu Province, College of Animal Science and Technology, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing 210095, People's Republic of China.
authors.forename: Guang-Zhen
authors.initials: GZ
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Aquatic Nutrition and Feed Science of Jiangsu Province, College of Animal Science and Technology, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing 210095, People's Republic of China.
authors.forename: Ding-Dong
authors.initials: DD
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Aquatic Nutrition and Feed Science of Jiangsu Province, College of Animal Science and Technology, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing 210095, People's Republic of China.
authors.forename: Hong-Yan
authors.initials: HY
authors.lastname: Tian
authors.affiliation: Key Laboratory of Aquatic Nutrition and Feed Science of Jiangsu Province, College of Animal Science and Technology, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing 210095, People's Republic of China.
authors.forename: Jun-Yi
authors.initials: JY
authors.lastname: Li
authors.affiliation: Key Laboratory of Aquatic Nutrition and Feed Science of Jiangsu Province, College of Animal Science and Technology, Nanjing Agricultural University, No. 1 Weigang Road, Nanjing 210095, People's Republic of China. Electronic address: wbliu@njau.edu.cn.
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Liu
mesh_terms: D000135:Acid Phosphatase / Q000097:blood; D016980:Aeromonas hydrophila / Q000276:immunology; D000704:Analysis of Variance; D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D017756:Aquaculture / Q000379:methods*; D003530:Cyprinidae / Q000254:growth & development* / Q000276:immunology*; D017931:DNA Primers / Q000235:genetics; D004040:Dietary Carbohydrates / Q000494:pharmacology; D060467:Disease Resistance / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D007075:Immunoglobulin M / Q000097:blood; D046529:Microscopy, Electron, Transmission; D009113:Muramidase / Q000097:blood; D009844:Oligosaccharides / Q000494:pharmacology*; D009195:Peroxidase / Q000097:blood; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D000975:Antioxidants; D017931:DNA Primers; D004040:Dietary Carbohydrates; D007075:Immunoglobulin M; D009844:Oligosaccharides; C116580:fructooligosaccharide; D009195:Peroxidase; D000135:Acid Phosphatase; D009113:Muramidase
keywords: Disease resistance; Feeding modes; Fructooligosaccharide; Immunity; Megalobrama amblycephala