title: Growth, immune responses and intestinal morphology of rainbow trout (Oncorhynchus mykiss) supplemented with commercial probiotics.
abstract: The influence of two commercial probiotics on the growth, innate immune parameters and intestinal morphology of rainbow trout (Oncorhynchus mykiss) juveniles (initial weight: 16.4 ± 0.4 g) was evaluated. Two probiotic types: A, multi-species (Bacillus sp., Pedicoccus sp., Enterococcus sp., Lactobacillus sp.) and B, mono-species (Pediococcus acidilactici) were tested at two levels each (A1: 1.5 g kg(-1), 8.6 × 10(5) CFU g(-1); A2: 3 g kg(-1), 1.6 × 10(6) CFU g(-1); B1: 0.1 g kg(-1), 2.6 × 10(4) CFU g(-1); B2: 0.2 g kg(-1), 7.2 × 10(4) CFU g(-1)) versus an unsupplemented diet (C). Diets were distributed to sextuplicate tanks, three times a day to visual satiation for 8 weeks. Growth performance and immune responses (plasma lysozyme, ACH50, peroxidase and head kidney respiratory burst) were determined at 4 and 8 weeks of feeding. Body composition and intestine morphology were determined at the end of the feeding trial. At 8 weeks, the lower dose of multi-species probiotic (A1) improved growth rate, while both probiotic types improved feed conversion rate compared to the control animals, at the lower dose of multi-species (A1) and at the higher dose of mono-species (B2) probiotics. Body composition did not vary between treatments. At 4 weeks, ACH50 activity was significantly higher in fish fed higher dose of B probiotic (B2, 123.7 ± 50.6 vs 44.1 ± 7.7 U.ml(-1) in control). At 8 weeks, lysozyme activity was higher in fish fed A1 (13.1 ± 5.2 μg ml(-1)) diet compared to fish fed control diet (7.8 ± 1 μg ml(-1)). Plasma peroxidase and head-kidney respiratory burst did not differ among the dietary treatments. Villi length and integrity and goblet cell counting of a cross section of the anterior intestine were not significantly different between groups. Results suggest benefits in zootechnical performance and immune humoral responses using both probiotic types, in a dose dependent manner, without apparent alterations in intestinal morphology.
authors: CIIMAR/CIMAR - Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto, Portugal; Instituto Politécnico de Coimbra, ESAC, Escola Superior Agrária de Coimbra, Bencanta, 3040-316 Coimbra, Portugal; CECAV-UTAD - Universidade de Trás-os-Montes e Alto Douro, 5000-801 Vila Real, Portugal. Electronic address: amelia.ramos@gmail.com.
authors: M A
authors: MA
authors: Ramos
authors: CIIMAR/CIMAR - Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas de Abel Salazar, Universidade de Porto, Rua Jorge Viterbo Ferreira n.° 228, 4050-313 Porto, Portugal.
authors: J F M
authors: JF
authors: Gonçalves
authors: CIIMAR/CIMAR - Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas de Abel Salazar, Universidade de Porto, Rua Jorge Viterbo Ferreira n.° 228, 4050-313 Porto, Portugal.
authors: S
authors: S
authors: Batista
authors: CIIMAR/CIMAR - Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto, Portugal.
authors: B
authors: B
authors: Costas
authors: CECAV-UTAD - Universidade de Trás-os-Montes e Alto Douro, 5000-801 Vila Real, Portugal.
authors: M A
authors: MA
authors: Pires
authors: CECAV-UTAD - Universidade de Trás-os-Montes e Alto Douro, 5000-801 Vila Real, Portugal.
authors: P
authors: P
authors: Rema
authors: CIIMAR/CIMAR - Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas de Abel Salazar, Universidade de Porto, Rua Jorge Viterbo Ferreira n.° 228, 4050-313 Porto, Portugal. Electronic address: rodrigo.ozorio@ciimar.up.pt.
authors: R O A
authors: RO
authors: Ozório
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D017756:Aquaculture; D001407:Bacillus / Q000737:chemistry*; D004032:Diet / Q000662:veterinary; D004305:Dose-Response Relationship, Drug; D007422:Intestines / Q000033:anatomy & histology / Q000254:growth & development; D056546:Lactobacillales / Q000737:chemistry*; D017686:Oncorhynchus mykiss / Q000033:anatomy & histology* / Q000254:growth & development / Q000276:immunology / Q000502:physiology*; D019936:Probiotics / Q000008:administration & dosage / Q000494:pharmacology*; D011897:Random Allocation
keywords: Growth; Innate immunity; Intestine histology; Probiotics; Rainbow trout