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| Author(s): |
Fernando Yugo Yamamoto
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Piracicaba. |
| Institution: | Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) |
| Defense date: | 2015-03-23 |
| Examining board members: |
José Eurico Possebon Cyrino;
Margarida Maria Barros;
José Fernando Machado Menten
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| Advisor: | José Eurico Possebon Cyrino |
| Abstract | |
Stressors in intensive fish farming affect fish physiological conditions and immune system, promoting susceptibility to infections and causing economic losses. To overcome this issue, using immunomodulatory nutrients such as tocopherol on fish feeds may become a prophylactic strategy to fish farms to ensure a higher survival and productivity. The present study aimed at determining vitamin E requirement of dourado, Salminus brasiliensis, through a dose dependent trial and how the immune system responded to vitamin E crescent doses. The experiment design was randomly distributed in seven treatments (n=4) of semi purified diets (0; 50; 100; 150; 200; 250 and 3,500 mg kg-1). After exposing the fish during 30 days for tocopherol depletion, fifteen dourado juveniles (20.04 ± 0.09 g) were stocked in 500 L tanks in a closed loop system and fed twice a day until apparent satiation. Differences in weight gain were observed however not in a vitamin E dose dependent way. After feeding for 78 days fish were challenged with intraperitoneal bacterial infection (Aeromonas hydrophila). Immunological parameters were measured before and after infection and no significant differences were observed in: blood leukocyte burst respiratory activity, serum lysozyme activity, serum protein and albumin, and survival. However a higher total serum globulin was detected after infection and the best response determined through a broken-line regression was 151.07 mg kg-1 of vitamin E on fish feed. Dietary requirement of vitamin E was determined by broken-line regression from thiobarbituric reactive substances of liver mithocondrial fraction to be 58.90 mg/kg of α-tocopherol acetate. (AU) | |
| FAPESP's process: | 12/19373-9 - Dietary vitamin E requirements of dourado Salminus brasiliensis (Cuvier, 1816) and the immunostimulatory effects |
| Grantee: | Fernando Yugo Yamamoto |
| Support Opportunities: | Scholarships in Brazil - Master |