Influence of dietary vitamin C dosage on turbot (Scophthalmus maximus) and European sea bass (Dicentrarchus labrax) nursery stages

• Published in: Comparative Biochemistry and Physiology Part A: Physiology
• Main Authors: Merchie, Greet, Lavens, Patrick, Storch, V, Übel, U, Nelis, Hans, De Leenheer, Andreas, Sorgeloos, Patrick
• Format: Article in Journal/Newspaper
• Language: English
• Published: 1996
• Subjects: Medicine and Health Sciences; Biology and Life Sciences; Scophthalmus maximus; Turbot
• Online Access: https://biblio.ugent.be/publication/188417; http://hdl.handle.net/1854/LU-188417; https://doi.org/10.1016/0300-9629(95)02104-3; https://biblio.ugent.be/publication/188417/file/01HBR663YGB847SJETF4E7BDR4

Stable forms of vitamin C were verified as dietary sources of ascorbic acid (AA) for the nursery stages of European sea bass and turbot. In a first experiment, various concentrations of ascorbyl palmitate (AP) and one level of AA 2-polyphosphate (ApP) were evaluated in a semi-purified diet for European sea bass, Dicentrarchus labrax. A significantly lower AA concentration was detected in the fry fed the AP-supplemented diets compared to the ApP-fed group, providing evidence that AP is an inferior source of vitamin C for young stages of sea bass. ApP was subsequently selected for the determination of the AA requirements of both sea bass and turbot (Scophthalmus maximus) fry. The AA levels incorporated in the body tissues reflected the levels of ApP in the diet, providing evidence of the bioavailability of this stable phosphate ester. Reduced production results were only obtained in the AA-free treatment, indicating that a level of 20 mg AA/kg is sufficient for sea bass and turbot during nursery rearing. This was supported with data from the ultrastructural evaluation of the hepatocytes. Results of challenge tests with pathogenic Vibrio strains remained inconclusive and did not provide evidence for an immunostimulative effect of high AA levels during the early post-weaning phase of these species.