title: Dietary Aloe vera supplementation on growth performance, some haemato-biochemical parameters and disease resistance against Streptococcus iniae in tilapia (GIFT).
abstract: This study investigated effects of dietary Aloe vera on growth performance, some haemato-biochemical parameters and disease resistance against Streptococcus iniae in tilapia (GIFT). Five groups were designed including a basal diet (control) and 100% A. vera powder incorporated in fish feed at 0.5% 1%, 2%, and 4%/kg feed, which were administered for 8 weeks. Fish fed 0.5%, 1%, and 2% A. vera supplemented diet significantly improved (p < 0.05) weight gain, absolute growth rate and specific growth rate. Feed intake significantly increased in fish fed with A. vera diet at 1% and 2%/kg feed. Feed efficiency ratio, feed conversion ratio, and hepatosomatic index were significantly enhanced in 4% A. vera supplemented fish over unsupplemented ones (p < 0.05). Several haemato-biochemical indices were examined before and after fish were challenged with S. iniae pathogen containing 7.7 × 10(6) CFU cells mL(-1). A. vera supplemented fish showed a significant increase (p < 0.05) in red blood cells, hematocrits (Hb), hemoglobin (Hb), white blood cells (WBC), neutrophils, monocytes, eosinophils, serum total protein, glucose and cortisol after challenge when compared to unsupplemented ones. Meanwhile, 4% A. vera supplemented fish showed a decrease (p < 0.05) in RBC, Hb, Ht, WBC, and mean corpuscular hemoglobin (MCH) after challenge compared to unsupplemented ones and other supplemented ones. In addition, lower mean corpuscular volume values (MCV) (p < 0.05) were observed in fish fed with A. vera diet at 2% and 4% A. vera/kg feed than those fed unsupplemented diet. Unchallenged fish fed 0.5%, 1%, and 2% A. vera showed significantly higher values (p < 0.05) of mean corpuscular hemoglobin concentration (MCHC) than those fed unsupplemented diet and 4% A. vera supplemented diet. There was a significant increase (p < 0.05) in the neutrophil to lymphocyte ratio (N/L) within experimental groups after challenge; N/L ratio in A. vera unsupplemented fish and those supplemented with A. vera diet at 1%/kg feed increased significantly (p < 0.05) throughout challenge period; while those fed 4% A. vera supplemented diet maintained higher values at all experimental stages among groups. There was a significant correlation (p < 0.05, r = 0.53) between N/L ratio and glucose concentration, 96 h after challenge. Aloe had no significant effect (p > 0.05) on the survival of the fish when compared to the control; no mortality was recorded in challenge trial. Overall, our results indicated that dietary aloe supplementation could improve growth, feed utilization, and haemato-biochemical parameters of cultured tilapia.
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China; Directorate of Aquaculture, Ministry of Fisheries and Marine Resources, Hardap, Namibia.
authors.forename: Ndakalimwe Naftal
authors.initials: NN
authors.lastname: Gabriel
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China; China Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, Jiangsu, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Qiang
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China.
authors.forename: Jie
authors.initials: J
authors.lastname: He
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China.
authors.forename: Xin Yu
authors.initials: XY
authors.lastname: Ma
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China.
authors.forename: Mathew D
authors.initials: MD
authors.lastname: Kpundeh
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China; China Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, Jiangsu, China. Electronic address: xup@ffr.cn.
authors.forename: Pao
authors.initials: P
authors.lastname: Xu
mesh_terms: D000504:Aloe / Q000737:chemistry*; D000818:Animals; D001786:Blood Glucose; D019587:Dietary Supplements; D060467:Disease Resistance / Q000187:drug effects* / Q000276:immunology; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects; D008214:Lymphocytes / Q000187:drug effects; D009504:Neutrophils / Q000187:drug effects; D010936:Plant Extracts / Q000032:analysis / Q000494:pharmacology*; D013291:Streptococcus / Q000276:immunology*; D017210:Tilapia / Q000254:growth & development* / Q000276:immunology*; D015430:Weight Gain / Q000187:drug effects
chemical_list: D001786:Blood Glucose; D010936:Plant Extracts
keywords: Bacterium; Challenge; Cichlidae; Feeding; Herbs; Immunity; Oreochromis; Survival