The Requirements Of Zn, Fe And Bioavailability Of Different Zn And Fe Sources For Juvenile Grouper Epinephelus Coioides

Feeding trials were conducted to investigate the effects of different Zn and Fe sources and levels on the growth performence,immune enzymes activity and elements content in tissue of grouper?Epinephelus coioides?.Results are presented as follows:1.Casein and fish meal were used as main protein resource,TBZC,ZnSO₄ and,Zn-MHA were used as zinc sources,to be made up experiment fodder that zinc added levels respectively was 0,10,20,40,80,160 mg/kg,the actual content of zinc in TBZC experiment fodder group respectively was 28.31,42.07,57.44,71.87,112.64,215.14mg/kg,the actual content of zinc in ZnSO₄ experiment fodder group respectively was 28.31,37.30,50.47,76.49,124.64,228.86mg/kg,the actual content of zinc in Zn-MHA experiment fodder group respectively was 28.31,37.30,50.47,76.49,124.64,228.86mg/kg?In total,sixteen disposes?the blank control group was shared?,Each disposes was three times and30 fish?Experimental fish initial weight was 10.24±0.07 g?The result showed that:whatever the source of zinc and zinc levels had no significant influence on grouper survival rate?P>0.05?;With the increasing of zinc added level,the WGR and SGR of TBZC experiment fodder group showed trend of rising before steady,there are significant differences between the groups?P<0.05?.the WGR and SGR of ZnSO₄'experiment fodder group both showed trend of rising before steady,the WGR and SGR of Zn-MHA'experiment fodder group both showed trend of rising before steady,when the added level was 160mg/kg,the WGR and SGR showed trend of decline?P<0.05?.?Fodder coefficient of all zinc source experimental group showed trend of downing before rising,The differences between the different zinc sources groups was significantly?P<0.05?.Three kind of zinc sources groups AKP?SOD?Cu-Zn SOD and CAT showed trend of rising before steady,the differences between the groups were significant?P<0.05?.Whatever kind zinc source were added,the zinc content of whole grouper fish showed trend of rising before steady,the differences between the groups were significant?P<0.05?;the manganese content of whole grouper fish declined significantly?P<0.05?;Affect on the iron,copper content of whole grouper fish was not significant?P<0.05?.Adding three kind of zinc sources had significantly effects on the zinc content of grouper'vertebrae,when TBZC used as zinc source,after the content of zinc reaching 20mg/kg,the zinc content of grouper'vertebrae kept steady;when ZnSO₄ used as zinc source,the zinc content of grouper'vertebrae in 0mg/kg group down significantly other groups?P<0.05?;the zinc content of grouper'vertebrae in Zn-MHA showed trend of rising before steady,the differences between the groups were significant?P<0.05?.Whatever kind zinc source were added,the content of iron,manganese,zinc,copper of grouper'liver were affected by different zinc added level fodder,there were no significant differences between these groups?P>0.05?.Based on whole body and vertebrae Zn concentration,by broken line analysis showed that optimum dietary Zn levels respectively was 65.05-68.47mg/kg,53.26-55.07mg/kg,50.06-55.47mg/kg,when ZnSO₄,TBZC,Zn-MHA were used as zinc sources.The RVB of TBZC and Zn-MHA were 124-214%,153-273%compared to ZnSO₄.2 Casein and fish meal were used as main protein resource,FeSO₄?Ferric citrate?Fe-C?and Fe-MHA were used as iron sources,to be made up experiment fodder that iron added levels respectively was 0,50,90,130,170,210mg/kg,the actual content of iron in FeSO₄ experiment fodder group respectively was 77.71,126.56,170.41,227.16,266.47,307.42mg/kg,the actual content of iron in Ferric citrate experiment fodder group respectively was 77.71,119.67,174.69,208.75,252.47,290.82mg/kg,the actual content of iron in Fe-MHA experiment fodder group respectively was 77.71,119.67,174.69,208.75,252.47,290.82ma/kg?In total,sixteen disposes?the blank control group was shared?,Each disposes was r three times,each test 25 fish,Experimental fish initial weight was12.19±0.14g?The experiment result showed that:whatever the source of iron and iron levels had no significant influence on grouper the WGR,survival rate and SGR?p>0.05?.With the increasing of iron added level,there were no significant differences between FeSO₄ groups?P>0.05?,there were significant differences between Ferric citrate group and Fe-MHA groups?P>0.05?.The group of 0 mg/kg was lower than other groups.When Ferric citrate and Fe-MHA were used as iron sources,the hematocrit showed a trend of rising,the differences between the groups were significant?P<0.05?.When FeSO₄ was used as iron source,with the increasing of iron added level,the hematocrit showed a trend of rising,while iron added level reaching 210mg/kg,it down obviously,the differences between the groups were significant?P<0.05?.Whatever kind iron source was added,the hemoglobin showed trend of rising before steady,when FeSO₄ was used as iron source,iron added level reaching 90mg/kg,the hemoglobin kept steady.When Ferric citrate and Fe-MHA were used as iron sources,iron added level reaching 50mg/kg,the hemoglobin kept steady;whatever kind iron source was added,it had significant effects on corpuscular volume?P<0.05?,with the increasing of iron added level,corpuscular volume showed trend of rising before steady.Whatever kind iron source was added,the content of iron in grouper showed trend of rising before steady,the differences between the groups were significant?P<0.05?;adding iron had no effects on the content of iron?manganese?zinc?copper of grouper?P<0.05??Added Three kind of iron source,it had no effects on grouper vertebrae'the content of iron and zinc?P<0.05?,vertebrae content manganese and copper showed trend of obvious decline?P<0.05?.Whatever kind iron source was added,the grouper liver iron content showed trend of rising before steady,the differences between the groups were significant?P<0.05?,liver's content of manganese declined obviously?P<0.05?,Different iron source and iron levels didn't have obviously effects on the grouper liver's the content of zinc and copper?Based on CAT activity,hemoglobin,whole body and liver Fe concentration,by broken line analysis showed that optimum dietary iron levels respectively was 168.01-179.07,167.06-173.22 and 149.07-156.88 mg/kg.The RVB of Ferric citrate and Fe-MHA were 97-107%,121-156%compared to FeSO₄.