title: The influence of various feeding patterns of emodin on growth, non-specific immune responses, and disease resistance to Aeromonas hydrophila in juvenile Wuchang bream (Megalobrama amblycephala).
abstract: The present study was conducted to evaluate the effect of various feeding patterns of emodin on growth, non-specific immune response, and disease resistance to Aeromonas hydrophila in juvenile Wuchang bream. Healthy Megalobrama amblycephala (initial weight: 3.47 ± 0.032) were grown in a circulating water system for 8 weeks. Five groups were studied: one control group was fed with a basal diet for eight weeks (Pattern 1, P1), and three treatment groups were fed with a trial diet of 30 mg emodin kg(-1) at one-week (Pattern 2, P2), two-week (Pattern 3, P3), four-week (Pattern 4, P4) intervals. The final treatment group maintained the trial diet for the entire eight-week study duration (Pattern 5, P5). Results indicated that different feeding patterns of emodin significantly influenced the weight gain rate of Wuchang bream (P < 0.05). Fish in the P4 treatment group had significantly higher rates of weight gain (WG) than those in other treatment groups. There were no significant differences in survival rates or feed conversion ratios (FCR) between treatment groups and the control group. White blood cell count (WBC), respiratory burst activity, superoxide dismutase (SOD) activity, myeloperoxidase (MPO) activity and tumor necrosis factor-α (TNF-α) activity were shown to increase at first and then decrease from P3 condition to P5 condition. Fish under P4 treatment showed the most significant improvement of all tested parameters compared to control. Significantly higher levels (P < 0.05) of plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activity were observed in P2 and P4 treatment groups when compared with the control group, while no significant differences were observed in the AST and ALT activity of fish in P2, P3, P4 and P5 treatment groups. In a bacterial challenge experiment with A. hydrophila, fish under P4 and P5 treatment showed lower cumulative mortality than the control group. The results of this study suggest that an initial 4-week feeding interval is recommended for the economic and practical culture of M. amblycephala.
authors.affiliation: Wuxi Fishery College, Nanjing Agriculture University, Wuxi 214081, China; Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China; College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: 2011205016@njau.edu.cn.
authors.forename: Yuan-yuan
authors.initials: YY
authors.lastname: Zhang
authors.affiliation: Wuxi Fishery College, Nanjing Agriculture University, Wuxi 214081, China; Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China. Electronic address: liub@ffrc.cn.
authors.forename: Bo
authors.initials: B
authors.lastname: Liu
authors.affiliation: Wuxi Fishery College, Nanjing Agriculture University, Wuxi 214081, China; Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China. Electronic address: gexp@ffrc.cn.
authors.forename: Xian-ping
authors.initials: XP
authors.lastname: Ge
authors.affiliation: Wuxi Fishery College, Nanjing Agriculture University, Wuxi 214081, China; College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: wbliu@njau.edu.cn.
authors.forename: Wen-bin
authors.initials: WB
authors.lastname: Liu
authors.affiliation: Wuxi Fishery College, Nanjing Agriculture University, Wuxi 214081, China; Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Xie
authors.affiliation: Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China.
authors.forename: Mingchun
authors.initials: M
authors.lastname: Ren
authors.affiliation: Wuxi Fishery College, Nanjing Agriculture University, Wuxi 214081, China; Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China.
authors.forename: Yan-ting
authors.initials: YT
authors.lastname: Cui
authors.affiliation: Wuxi Fishery College, Nanjing Agriculture University, Wuxi 214081, China; Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China.
authors.forename: Si-lei
authors.initials: SL
authors.lastname: Xia
authors.affiliation: Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China.
authors.forename: Ruli
authors.initials: R
authors.lastname: Chen
authors.affiliation: Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China.
authors.forename: Qunlan
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China.
authors.forename: Liangkun
authors.initials: L
authors.lastname: Pan
authors.affiliation: Yancheng Institute of Technology, Yancheng 224051, China.
authors.forename: Yebing
authors.initials: Y
authors.lastname: Yu
mesh_terms: D016980:Aeromonas hydrophila / Q000276:immunology*; D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood; D003530:Cyprinidae; D004642:Emodin / Q000008:administration & dosage / Q000494:pharmacology*; D005247:Feeding Behavior; D005393:Fish Diseases / Q000276:immunology / Q000382:microbiology*; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy / Q000276:immunology*; D007113:Immunity, Innate / Q000276:immunology*; D007958:Leukocyte Count / Q000662:veterinary; D009504:Neutrophils; D011897:Random Allocation; D016897:Respiratory Burst / Q000276:immunology; D013482:Superoxide Dismutase / Q000097:blood; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D017392:Thiobarbituric Acid Reactive Substances; D014409:Tumor Necrosis Factor-alpha; D013482:Superoxide Dismutase; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D004642:Emodin
keywords: Emodin; Feeding patterns; Growth; Megalobrama amblycephala; Non-specific immunity