Effects of Dietary Vitamin E Supplementation on Growth Performance, Body Composition of Golden Trevally, Gnathanodon speciosus

Abstract

Golden trevally, Gnathanodon speciosus is a new candidate for aquaculture in Viet Nam. This species has rapid growth, high market value, delectable flavour. Finding solutions to enhance production by promoting growth is necessary in golden trevally aquaculture. Vitamin E is one of the feed supplements which has proven the benefit on other aquaculture species but there has not been any study on golden trevally. Therefore, this experiment was designed to test the effect of vitamin E on the golden trevally, Gnathanodon speciosus. Three levels of vitamin E (50, 100, and 200 mg kg-1 diet) were supplemented to the basal diet (control diet). There was 4 diet treatments and 3 replicates for each treatment. The golden trevally (initial weight 7.63 g ± 0.13 (SEM)) were fed experimental diets for eight weeks. The growth performance and protein and lipid content of tissues were evaluated. At the end of the feeding trial (week 8), the presence of vitamin E in a fish's diet resulted in a significant increase in its growth rate (P < 0.05). The survival rate of fish fed diets containing 50 - 200 mg of vitamin E was substantially higher than that of control fish. In addition, protein and lipid levels in the flesh of golden trevally increased significantly as vitamin levels in their diets rose. For optimal growth and survival, it is recommended to supplement the diet of golden trevally with at least 50 mg of vitamin E per kilogramme. In conclusion, supplementing the diet with vitamin E improves growth, survival, and body composition in juveniles of this species. As this experiment is the first study on the effects of vitamin E on golden trevally, it is worthy of investigation.