Effects Of Different Zinc Sources And Different Zinc Supplemental Levels On Juvenile Hybrid Tilapia (Oreochromis Aureus×Oreochromis Niloticus)

The study was conducted on Oreochromis aureus×Oreochromis niloticus, theeffects of dietary different zinc sourse and different zinc level on gowth, blood andantioxidant ability.A 56-day growth trial was conducted to investigate the effect of six zincconcentrations (0, 20, 40, 80, 160, 320mg/kgbe described asⅠS,ⅡS,ⅢS,ⅣS,ⅤS,ⅥS) on growth, blood and antioxidant ability of muscle of juvenile tilapia(4.13±0.32g) with zinc sulfate as zinc souces. Results show that in the groupⅡS,weight gain, specific growth rate, the zinc concentration in bones of fish and bodyprotein content were higher than in other groups.The fat deposited in muscle and liverofⅡS was markedly lower than other groups (P＜0.05). The erythrocytes number andhematocrit ofⅡS group were significantly higher than other groups (P＜0.05) exceptthe groupⅢS (P＞0.05). The TBARS values ( Thiobarbituricacid-reactivesubstances)in muscle of theⅡS group were significantly lower than the groupⅠS (P＜0.01). Results of this study indicated that the effect of different zinc sulfate levels ongrowth, antidease ability and antioxidant ability of tilapia muscles was significant,especially in 20-40 mg zinc/kg diet group.A 56-day growth trial was conducted to investigate the effect of six zincconcentrations (0, 5, 10, 20, 40, 80mg/kgbe described asⅠM,ⅡM,ⅢM,ⅣM,ⅤM,ⅥM) on growth, blood and antioxidant ability of muscle of juvenile tilapia(4.12±0.33g) with methioinum zinc as souces. Results showed that feed coefficient,body fat deposited, moisture and fat content in liver decreased as dietary zincconcentration increased; weight gain, specific growth rate, zinc concentration in bonesand erythrocytes number are highest when zinc concentration isⅢM; TBARS value(Thiobarbituricacid-reactive substances) is lowest when zinc concentration isⅡM.So juvenile tilapia have fast growth and strengthing immunity and antioxidant activitywhen methioinum zinc concentration in diet is 5-10 mg/kg.