Study On Nutrition Requirements Of Iron And Copper In Genetically Improved Farmed Tilapia

This paper studied on the requirement of dietary iron and copper ofthe genetically improved farmed tilapia(GIFT)，and the effects on the ironabsorption in blood and muscle.Semi-purified test diets were used，withcasein and white fish meal as the main protein source， fish oil andsoybean oil as the source of fat，with ferrous sulfate (FeSO4) as the sourceof iron，copper sulfate (CuSO4) as the copper source．Using a4×4twofactor interaction design，diets was added to iron40，80，120，160mg/kg4levels，and copper2，4，6，8mg/kg4levels，which was made to16kinds of pellet feed．The GIFT was raised for two months．Study on thegrowth performance，body composition，blood indexes of iron and copperin GIFT，and the blood and muscle on iron absorption character．The mainresults were as follows：1． With different dietary iron， copper level in the GIFT dietsintaking，the weight gain rate，specific growth rate，fatness and feedcoefficient were not significant influence (P>0.05)．When the copper indiet under the same adding level conditions，with the quantity of diet ironincreasing，the specific growth rate increased firstly and then decreased，and on the diet of iron levels for80mg/kg the SGR reached to themaximum value． When the diet iron reaching to80mg/kg， copper levelreaching to8mg/kg，the weight gain rate reached a maximum value of1209.4%，feed coefficient reached a minimum of0.80．These resultsshowed that feed adding with suitable iron，copper level could promotethe rapid growth of GIFT．2．Different dietary iron levels could influence on GIFT body proteincontent significantly (P<0.05)． When iron levels of the diet reaching80mg/kg， fish protein content reached the maximum level， andsignificantly higher than all other groups (P<0.05)．Dietary iron，copper level on the GIFT body moisture and fat content were not significanteffect (P>0.05)．Show feed added with appropriate iron levels increaseGIFT body protein content，on muscle quality of a certain degree ofimprovement．3．Different copper levels had a significantly effect on the liver andbone of the vertebral column of copper content of GIFT(P<0.05)．Whenthe copper level of diet was8mg/kg，the liver copper content reached themaximum level，when the copper level of diet was4mg/kg，the content ofcopper in spinal bone reached the maximum level． The copper levels ofdiet had no significantly effect on the copper content of gill andmuscle(P>0.05)． The iron content of diet could influence on GIFT liveriron，copper content significantly(P<0.05)．When the feed of iron addedlevels for40mg/kg，hepatic iron and copper content reached the maximumvalue，and significantly higher than all other test groups (P<0.05)．Thedifferent iron levels on the gills， spinal bone and muscle in the iron， thecopper contents were not significant， but with the feed iron levelsincreased，the iron content of liver and bone of the vertebral column wereincreased (P>0.05)．4． With the increase in the dietary iron, CAT activity of serumcatalase was increased and then decreased significantly (P<0.05), itreached a peak at80mg/kg and was significantly higher than othergroups(P<0.05).Copper in feed supplementation on GIFT in the plasma of copperzinc superoxide dismutase (Cu-Zn SOD)activity had significant effect (P<0.05)．Copper in feed added with increased levels of plasma Cu-Zn SODactivity showed increased firstly and then decreased，when the copper ofdiet reaching8mg/kg，Cu-Zn SOD activity reached a minimum，and otherexperimental groups were significant differences(P<0.05)．Dietary iron，copper level could not effect significantly on the number of red blood cell， hematocrit and the content of hemoglobin, respectively (P>0.05),．5． GIFT in feeding iron diet， the content of iron in the blood andmuscle changed regularly with time．0.5h after feeded iron diet，the bloodiron content of the fish reached the maximum level， then decreasedgradually，and dropped to a lower level until24.5h. The content of iron inblood was significantly higher after the fish feeded (P<0.05)．The contentof iron in muscle increased and then decreased with time, and reached apeak at4.5h,which was higher after GIFT was feeded．...