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A comparison of the effect of silicone coated ascorbic acid and ascorbyl phosphate on the course of ichthyophthiriosis in rainbow trout, Oncorhynchus mykiss (Walbaum)
Author(s) -
WAHLI T.,
FRISCHKNECHT R.,
SCHMITT M.,
GABAUDAN J.,
VERLHAC V.,
MEIER W.
Publication year - 1995
Publication title -
journal of fish diseases
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 85
eISSN - 1365-2761
pISSN - 0140-7775
DOI - 10.1111/j.1365-2761.1995.tb00311.x
Subject(s) - rainbow trout , ichthyophthirius multifiliis , ascorbic acid , vitamin c , biology , vitamin , food science , phosphate , trout , zoology , biochemistry , fish <actinopterygii> , fishery
. The aim of the present study was to compare the effect of high and low doses of different vitamin C formulations on the course of ichthyophthiriosis ( Ichthyophthirius multifiliis infection) in rainbow trout. After a depletion period, trout fingerlings were fed diets deficient in vitamin C(AA 0), or containing different levels of silicone coated ascorbic acid (AA; 50/200 mg kg feed −1 ) or ascorbyl phosphate (AP; 50/2000 mg AA equivalent kg feed −1 ). Fish infected with I. multifiliis demonstrated a significant reduction in mortality when fed high levels of AA or AP. A correlation between the parasite burden and the vitamin C content in the diet was not found. Specific immunity—measured as immobilization litre of sera—was not influenced by the level or the formulation of vitamin C in the diet. The most probable mechanism of high level doses of vitamin C is an increase of the general health status expressed as an improved nonspecific resistance and ability to cope with different stressors. In rainbow trout infected with I. multifiliis , the beneficial effect of ascorbyl phosphate is equal to that of silicone coated ascorbic acid, and therefore, the more stable AP may be a valuable alternative for use in fish diets.