Effects Of Dietary Iron, Zinc And Copper On Growth, Metabolic Responses And Antioxidation In Abalone Haliotis Discus Hannai Ino

A series of experiments were conducted to determine the effects f dietary iron, zinc and copper on growth,metabolic responses and antioxidation in juvenile abalone(Haliotis discus hannai Ino) with FeSO4·7H2O as iron source, ZnSO4·7H2O as zinc source and CuSO4·5H2O as copper source.The results of the present study are summarized as follows:1.A one-factorial experiment was conducted to determine the effects of iron deficiency and overload on growth, metabolic responses and antioxidation in juvenile abalone Haliotis discus hannai. The juveniles (initial mean weight, 0.29±0.00g; initial mean shell length, 13.05±0.02mm) were divided into four triplicate groups, and fed on one of the four semi-purified diets containing 29.7(deficiency), 65.7 (control), 1267.2 (overload), 6264.7 (overload) mg iron/kg dry diet, respectively, for 28 weeks in a flow-through system.The results showed that there were no significant difference in the survival of abalone among four dietary treatments (P>0.05). The average weight gain rate (WGR, %) and daily increment in shell length (DISL) were significantly increased with rising content of dietary iron (P<0.05) and reached the highest value in in 1267.2 and 6264.7 mg iron /kg diet treatments. Dietary iron significantly elevated the soft body protein content, however, significantly decreased the lipid content (P<0.05). Iron concentrations in muscle, hepatopancreas, serum and shell of abalone significantly increased with the dietary iron, however, copper, manganese and zinc concentrations in these tissues significantly decreased with the dietary iron (P<0.05). The activities of serum and hepatopancres acid phosphatase (ACP) and hepatopancres alkaline phosphatase (AKP) significantly decreased with the increasing of dietary content of iron(P<0.05).The activities of serum superoxide dimutase (SOD)and hepatopancres Catalase (CAT) and hepatopancres total anti-oxidation competence (T-AOC) increased then decreased with the increasing of dietary content of iron(P<0.05). The lowest values of SOD, CAT activities and T-AOC were found in the treatment with 6264.7 mg/kg dietary iron.The malonaldehyde (MDA) concentration of the test diets increased as the iron levels in the diets increased indicating that iron catalyzed lipid oxidation was occurring. The treatment of highest iron level had the highest level of MDA in hepatopancreas. The VE levels of diet and hepatopancreas decreased with increasing of dietary content of iron(P<0.05). According to these results, the abalone fed with diets of high iron level (1267.2 and 6264.7 mg/kg) kept better growth at the end of the experiments. But high iron catalyzed lipid oxidation in diet and tissue and increased tissue oxidative stress indicated that high dietary iron affected the healthy of the abalone.2. A two-factorial experiment was conducted to determine iron and zinc interaction on growth, metabolic responses and antioxidant in juvenile abalone Haliotis discus hannai (average weight0.29±0.00g ; average shell length 13.05±0.02mm). Totally nine semi-purified diets were made to provide graded levels of iron(0, 65, 1300 mg/kg, supplied as FeSO4·7H2O)and zinc(0, 35, 700 mg/kg, supplied as ZnSO4·7H2O). Each treatment were triplicate. .The experimental period lasted 28 weeks in a flow-through systems. The results showed that there was no significant difference in the survival rate(>97.50%, P>0.05) of juvenile abalone in the feeding trial. 1300 mg iron /kg diet treatments significantly improved the growth performance of abalone, and dietary iron significantly elevated the soft body protein content, though the lipid content of abalones were significantly decreased (P<0.05). The interaction of Fe and Zn to the soft body lipid content was significant (P<0.05). The iron concentration of abalone body tissues(including hepatopancreas, muscle, serum and shell) decreased and the zinc concentration increased with the uprising dietary zinc treatments, when dietary iron level was invariable. However, when dietary zinc level was invariable ,the iron concentration of abalone body tissues significantly increased and the zinc concentration of tissues fluctuated by the treatment of increase dietary iron level. The concentration of abalone tissues iron (zinc) significantly decreased when the dietary zinc (iron) levels was highest(P<0.05 ). Iron and zinc had obviously interactions on the activities of serum acid phosphatase(ACP), alkaline phosphatase (AKP) and hepatopancreas ACP and tissue metal concentrations (the Fe and Zn concentration of hepatopancreas, the Fe level of muscle, and the Fe, Zn, Cu and Mn concentrations of serum)(P<0.05 ). The activities of hepatopancres Catalase (CAT) and total anti-oxidation competence (T-AOC) have a up and down trend along with the increasing dietary content of iron (P<0.05). There were significant interactions between iron and zinc on the activities of serum superoxide dismutase (SOD) and hepatopancreas CAT (P<0.05 ). The malonaldehyde (MDA) levels of diet was significantly increased by the dietary iron supplement(P<0.05), however, the iron supplement decreased the VE levels of diet and hepatopancreas (P<0.05). And the dietary ion did not have interactions on the serum SOD and hepatopancreas CAT (P<0.05).3. Iron and copper are essential micronutrients for aquatic animals health. The abalone( Haliotis discus hannai ino) juveniles (initial weight 0.33±0.00 g, initial shell length 13.54±0.04 mm) were fed nine experimental diets containing 0, 65, 1300 mg iron /kg (supplied as FeSO4·7H2O), combined with 0, 4, 80 mg copper /kg dry diet (supplied as CuSO4·7H2O), in order to elucidate the interaction between iron and copper on growth, metabolic responses and antioxidation in abalone( Haliotis discus hanni ino). Each treatment had three replicates.The experimental period lasted 28 weeks in a flow-through systems. 1300 mg iron /kg diet treatments significantly improved the growth performance of abalone, and dietary iron significantly elevated the soft body protein content, though the lipid content of abalones were significantly decreased (P<0.05). The iron concentrations of hepatopancreas, muscle and serum were higher than 1.80 copper mg/kg when dietary copper was 4.24 mg/kg and dietary iron was 0 and 65 mg/kg, therefore this indicated copper increased iron absoption when dietary iron was lower. The concentration of abalone tissues iron (copper) significantly decreased when the dietary copper (iron) levels was highest (P<0.05 ). Iron and copper had interactions on the activities of serum and hepatopancreas acid phosphatase(ACP) and alkaline phosphatase (AKP) and tissue metal concentrations (the Fe, Cu,Zn and Mn concentrations of hepatopancreas, the Mn level of muscle, and the Fe, Zn and Mn concentrations of serum)(P<0.05). The activities of hepatopancres Catalase (CAT) and hepatopancres total anti-oxidation competence (T-AOC) increased then decreased with the with increasing of dietary content of iron(P<0.05). There were significant interactions between iron and zinc on the activities of serum and hepatopancreas superoxide dismutase (SOD) and hepatopancreas CAT (P<0.05 ).The malonaldehyde (MDA) levels of diet increased with increasing of dietary content of iron(P<0.05), however the VE levels of diet and hepatopancreas decreaed with increasing of dietary content of iron(P<0.05). There were significant interactions between Fe and Zn on the activities of serum SOD and hepatopancreas SOD and CAT (P<0.05).