title: Dietary administration of a commercial mixed-species probiotic improves growth performance and modulates the intestinal immunity of tilapia, Oreochromis niloticus.
abstract: The growth performance, immunological status, intestinal morphology and microbiology of tilapia, Oreochromis niloticus, were investigated after dietary administration of the commercial probiotic AquaStar(®) Growout. Tilapia (29.02 ± 0.33 g) were split into five treatments; control (CON), 1.5 g kg(-1) probiotic (PRO-1.5), 3 g kg(-1) probiotic (PRO-3), pulsed probiotic feeding (PRO-PULSE) or an initial probiotic feed followed by control feeding (PRO-INI). After six weeks of experimental feeding, fish fed PRO-3 displayed significantly higher final weight, weight gain and SGR compared to the CON or PRO-INI treatments. Supplementation of the probiotic at this dose induced an up-regulation of intestinal caspase-3, PCNA and HSP70 mRNA levels compared to the CON fed fish. Immuno-modulatory pathways were also affected; significantly higher expression of TLR2, pro-inflammatory genes TNFα and IL-1β, and anti-inflammatory genes IL-10 and TGFβ suggest that the probiotic may potentiate a higher state of mucosal tolerance and immuno-readiness. Histological appraisal revealed significantly higher numbers of intraepithelial leucocytes in the intestine of PRO-3 fed fish compared with treatments CON, PRO-PULSE and PRO-INI but not PRO-1.5. Additionally, fish receiving PRO-3 had a significantly higher abundance of goblet cells in their mid-intestine when compared with fish from all other treatments. Together, these data suggest that continuous provision of AquaStar(®) Growout at 3 g kg(-1) can improve tilapia growth and elevate the intestinal immunological status of the host.
authors.affiliation: Aquaculture and Fish Nutrition Research Group, School of Biological Sciences, Plymouth, Devon, PL4 8AA, UK. Electronic address: benedict.standen@yahoo.co.uk.
authors.forename: B T
authors.initials: BT
authors.lastname: Standen
authors.affiliation: Aquaculture and Fish Nutrition Research Group, School of Biological Sciences, Plymouth, Devon, PL4 8AA, UK.
authors.forename: D L
authors.initials: DL
authors.lastname: Peggs
authors.affiliation: Aquaculture and Fish Nutrition Research Group, School of Biological Sciences, Plymouth, Devon, PL4 8AA, UK.
authors.forename: M D
authors.initials: MD
authors.lastname: Rawling
authors.affiliation: School of Biomedical and Healthcare Sciences, Plymouth University, Drake Circus, Plymouth, Devon, PL4 8AA, UK.
authors.forename: A
authors.initials: A
authors.lastname: Foey
authors.affiliation: Department Animal Production, Welfare and Veterinary Science, Harper Adams University, Newport, TF10 8NB, UK.
authors.forename: S J
authors.initials: SJ
authors.lastname: Davies
authors.affiliation: Biomin Holding GmbH, Industriestrasse 21, 3130, Herzogenburg, Austria.
authors.forename: G A
authors.initials: GA
authors.lastname: Santos
authors.affiliation: Aquaculture and Fish Nutrition Research Group, School of Biological Sciences, Plymouth, Devon, PL4 8AA, UK. Electronic address: Daniel.merrifield@plymouth.ac.uk.
authors.forename: D L
authors.initials: DL
authors.lastname: Merrifield
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D023681:Cichlids / Q000235:genetics / Q000254:growth & development* / Q000276:immunology*; D004032:Diet / Q000662:veterinary; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D000069196:Gastrointestinal Microbiome / Q000276:immunology*; D007422:Intestines / Q000276:immunology* / Q000382:microbiology; D019936:Probiotics; D011897:Random Allocation; D015854:Up-Regulation
chemical_list: D029941:Fish Proteins
keywords: Fish; Gene expression; Growth performance; Histology; Immunity; Intestinal microbiology; Probiotic; Tilapia