title: The effects of Lactobacillus acidophilus as feed supplement on skin mucosal immune parameters, intestinal microbiota, stress resistance and growth performance of black swordtail (Xiphophorus helleri).
abstract: The present study evaluates the effects of different levels of dietary Lactobacillus acidophilus as feed supplement on intestinal microbiota, skin mucus immune parameters and salinity stress resistance as well as growth performance of black swordtail (Xiphophorus helleri). One-thousand and eight hundred healthy black swordtail larvae (0.03 ± 0.001 g) were randomly distributed in 12 tanks (100 L) at a density of 150 fish per aquaria and fed different levels of dietary L. acidophilus (0, 1.5 × 10(8), 3 × 10(8) and 6 × 10(8) CFU g(-1)) for 10 weeks. At the end of trial, there were significant differences among antibacterial activity of skin mucus in probiotic fed fish and control group (P < 0.05). Furthermore, the skin mucus protein level and alkaline phosphatase activity in control group were significantly lower than those of L. acidophilus fed fish (P < 0.05). Microbiological assessments revealed that feeding with probiotic supplemented diet remarkably increased total autochthonous bacteria and autochthonous lactic acid bacteria levels (P < 0.05). The results showed that dietary administration of L. acidophilus significantly elevated black swordtail resistance against salinity stress (i.e survival %) (P < 0.05). Also, dietary administration of different levels of L. acidophilus improved weight gain, SGR, FCR compared to fish fed unsupplemented diet (P < 0.05). These results demonstrate beneficial effects of dietary L. acidophilus on mucosal immune parameters, intestinal microbiota, stress resistance and growth parameters of black swordtail and the appropriate inclusion is 6 × 10(8) CFU g(-1).
authors.affiliation: Department of Fisheries, Faculty of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran. Electronic address: hoseinifar@gau.ac.ir.
authors.forename: Seyed Hossein
authors.initials: SH
authors.lastname: Hoseinifar
authors.affiliation: Fisheries Department, Faculty of Natural Resources, The University of Guilan, Sowmeh Sara, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Roosta
authors.affiliation: Department of Fisheries, Faculty of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
authors.forename: Abdolmajid
authors.initials: A
authors.lastname: Hajimoradloo
authors.affiliation: Department of Fisheries, Sari University of Agricultural Sciences and Natural Resources, Iran.
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Vakili
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D003532:Cyprinodontiformes / Q000254:growth & development / Q000276:immunology / Q000502:physiology*; D004032:Diet / Q000662:veterinary*; D018928:Immunity, Mucosal; D007422:Intestines / Q000382:microbiology*; D007779:Lactobacillus acidophilus / Q000737:chemistry*; D064307:Microbiota; D019936:Probiotics; D012867:Skin / Q000276:immunology; D013312:Stress, Physiological
keywords: Black swordtail; Immune response; Intestinal microbiota; Lactobacillus acidophilus; Skin mucus