Increasing supplemental lipid levels to 14% significantly increased whole body lipid and decreased moisture, as has been reported for several fish species fed increasing levels of dietary lipid.
Other studies, however, showed that carcass lipid of channel catfish and muscle lipid content of European sea bass and hybrid striped bass were not affected by dietary lipid levels.
Dietary levels of vitamin E had no effect of body protein, ash and moisture, but body lipid significantly increased in fish fed 100 mg/kg supplemental vitamin E.
The significant increase in body lipid of fish fed this diet could not be explained since fish fed diets supplemented with 200 mg supplemental vitamin E had similar body lipid as the group fed 50 mg supplemental vitamin E.
Watanabe et al. and Huang and Huang reported that whole body proximate composition of common carp (Cyprinus carpio) and hybrid tilapia, respectively was unaffected by dietary levels of vitamin E.