EFFECTS OF DIETARY COPPER AND CALCIUM LEVELS ON GROWTH, ANTIOXIDANT ENZYME AND LIPID METABOLISM ENZYME ACTIVITIES OF JUVENILE LARGER YELLOW CROAKER LARIMICHTHYS CROCEA

To evaluate effects of dietary copper and calcium on juvenile larger yellow croaker Larimichthys crocea, four experimental diets (-Cu-Ca, +Cu-Ca, -Cu+Ca and +Cu+Ca) were formulated containing two different levels of copper (4 and 24 mg/kg) and of cadmium (0.5% and 3%) to feed juvenile large yellow croaker (4.050.31) g in tripli-cate for 10 weeks. The results indicated that the addition of Cu decreased fish survival rate, final body weight and weight gain (P0.05). As expected, the Cu diets enhanced liver and muscle Cu concentrations, Interestingly, the Ca diets diminished muscle Cu concentration (P0.05). The supplement of Cu decreased liver glycogen concentration, liver superoxide dismutase, catalase, glutathione peroxidase, 6-phosphogluconate dehydrogenase, isocitrate dehydrogenase, and fatty acid synthase activities, but it it enhanced thiobarbituric acid reactive substance content and lipoprotein lipase activity (P0.05). The interaction between Cu and Ca on muscle Cu concentration, thiobarbituric acid reac-tive substance content, 6-phosphogluconate dehydrogenase, fatty acid synthase and lipoprotein lipase activities was identified (P0.05). This study indicated that calcium supplement mitigated injuries in fish by high copper intake.