Antioxidant effect of
dietary tocopherol and ascorbic acid on growth and survival of Litopenaeus
vannamei postlarvae
N. Ruff , P. Lavens, J.-Z. Huo, P. Sorgeloos, H.J. Nelis, A.
De Leenheer-2001
Aquaculture
International, 9(2):
115-126
Abstract:
The nutritional effect of vitamin E in diets for Litopenaeus
vannamei postlarvae (PL19) was investigated. Four formulated diets with
different combinations of α-tocopheryl
acetate (α-TA), ascorbic acid (AA) and
highly unsaturated fatty acids (HUFA) were tested, using four replicates.
No significant differences in survival were observed
among treatments after 34 days of feeding. However, shrimp fed with a diet
containing 2% fish oil (low n-3 HUFA content), 200 mg.kg-1 α-TA
and 100 mg.kg-1 AA (diet H/E/C) showed significantly better
growth than those fed a diet supplemented with 5% fish oil (high n-3 HUFA
content), 200 mg.kg-1 α-TA
and 100 mg.kg-1 AA (diet H+/E/C). Shrimp fed with a diet
containing 5% fish oil, 900 mg.kg-1 α-TA
and 100 mg.kg-1 AA (diet H+/E+/C) showed a significantly higher
tissue level of n-6 PUFA than postlarvae fed diet H+/E/C. No definite
conclusion could be drawn about a possible interaction between α-TA
and AA, since a comparison of the diet containing 5% fish oil, 200 mg.kg-1
α-TA and 700 mg.kg-1 AA
(H+/E+/C+) and the diet H+/E/C did not show any significant differences in
any of the measured parameters. The antioxidative status of the shrimp
tissue (measured by means of the thiobarbituric acid (TBA) assay and
expressed as nM malonaldehyde (MA) per gramme dry weight) was equal for all
treatments. Nevertheless, there was a slightly lower MA value with the diet
H+/E/C+, indicating that AA may be an effective antioxidant in the aqueous
phase and at the water/lipid interface of the tissue. The tissue levels of α-T
and AA were highly dependent on the amounts in diets and no correlation
between α-T and AA incorporation could
be observed.