Dietary vitamin E affects the growth and health of the juvenile groupers (Epinephelus malabaricus)
This research determined the influence of dietary vitamin E levels on the growth, body composition and various health indices of juvenile Epinephelus malabaricus. Five experimental diets were formulated by adding all-rac-a-tocopherol in 0, 200, 400, 1000 and 3000mg/kg feed to the basal feed that used casein as the sole protein source. The juveniles, having an average weight of 30g, were cultivated in an indoor closed recirculation system, with 6 fishes in each tank, and 3 tanks for each experimental feed. After the 17-week feeding trial, weight gain of the fish (170-250%) was not significantly affected by the vitamin E treatments. The supplemental level of vitamin E was positively related to the lipid levels in liver, but was negatively related to the protein levels in liver. Total w-3 HUFA of polar lipids in body muscle were decreased with the increasing supply of vitamin E. It was observed on the 11th week and beyond that the fish fed with the vitamin-free diet were prone to fail in taking in feed particles although their responses to feeding were of no difference to the supplemental groups. But once the supplemental levels of vitamin E were higher than 400mg/kg no difference in feeding failure was detected, indicating deficiency of vitamin E detrimentally affected fish feeding. Plasma AST activities in the 0 and 3000mg/kg groups were significantly higher than those of the other groups. Histological sections of fish liver indicated that liver cells in low vitamin E groups showed signs of vacuolization. TBARS (thiobarbituric acid reactive substances) decreased with the increasing vitamin E levels in the feed. Vitamin E showed limited enhancement on the immune parameters studied. Except that agglutination titter was significantly higher in fish fed the high vitamin E diet (3000mg/kg) and serum lysozyme and erythrocyte SOD showed highest activity in 200 and 400mg/kg groups, intracellular super oxide anion of macrophages and serum alternative complement pathway activities were not significantly affected by vitamin E supplementation.
Advisor:Chen-Huei Huang; Shi-Yen Shiau; Houng-Yung Chen
School:National Sun Yat-Sen University
School Location:China - Taiwan
Source Type:Master's Thesis
Keywords:grouper immunity fish vit e
Date of Publication:06/21/2001