Effects of dietary ascorbic
acid/iron ratio on some production traits, lipid peroxide state and
amount/activity of the glutathione redox system in African catfish Clarias
gariepinus (Burchell) fingerlings
H.
Elbaraasi, M. Mézes, K. Balogh, L. Horváth, I. Csengeri-2004
Aquaculture
Research, 35(3):
256-262
Abstract:
African catfish Clarias gariepinus (Burchell)
fingerlings (3.16-3.92 g initial body weight) were investigated for 30
days in four different groups using different amounts of l-ascorbic acid (AA) and iron (supplied
as FeC6H5O7) in their feedings. Diet 1
(control): no addition of AA or iron; diet 2 (H-AA/FE): high (600 mg kg-1)
AA and low (218 mg kg-1) iron; diet 3 (H-HE/AA): high
(364 mg kg-1) iron and low (200 mg kg-1)
AA; and an unfed group, which was investigated only for 15 days due to high
mortality. The live weight gain, feed intake, specific growth rate (SGR; %
body weight day-1) and feed conversion rate (FCR) were measured
or calculated. At the end of the experimental period, the whole body content
of AA, iron, reduced glutathione (GSH), glutathione disulphide (GSSG) and
malondialdehyde (MDA), as well as the glutathione peroxidase (GSHPx)
activity, were measured. The production traits did not differ significantly
as a result of the different AA and iron contents of the feed. AA content
increased significantly in all the groups as compared with the initial
value, except in the unfed group. The difference between the treated groups
as compared with the control, with regard to the two AA/iron treated groups,
was also significant. The iron content in the fish body increased
significantly compared with the initial value, except in the unfed group.
The difference compared with the control was significant only in the H-FE/AA
group. The difference between the groups that consumed low and high iron
content diets was also significant. The GSH and GSSG content, as well as the
GSH/GSSG ratio and GSHPx activity of the fish body, did not differ
significantly as compared with the initial value or with the control. The
lipid peroxide status, as measured by the MDA content, did not differ
significantly either as an effect of the AA and iron supplementation, but
decreased as an effect of ageing and starvation. It may be concluded that,
under the present experimental conditions, the C. gariepinus
fingerling tissue stores of AA and/or iron increased as a result of feed
supplementation, but without altering the actual lipid peroxide status and
the amount/activity of the glutathione redox system.
(Department of Fish Culture, Faculty of Agricultural
Sciences, Szent István University, Páter Kárloy u. 1, H-2103 Gödöllő,
Hungary. E-mail: ehoussein@nt.ktg.gau.hu)