Effects Of Enteric-type Zinc On Growth,Biochemical Parameters And Trace Element Concentrations In Tissue Of G. Tilapia

In this experiment,ZnSO₄ and Zn-gly were used as the object to prepare enteric-type ZnSO₄ and enteric-type Zn-gly.The encapsulation efficiency of enteric-type ZnSO₄ was 81.74%,and the encapsulation efficiency of enteric-type Zn-gly was 88.51%.The average release rate of enteric-type ZnSO₄ in acidic environment was 7.24%.At pH 6.8,the release rate at the first sampling was 75.89%,and the release rate at the third sampling was 97.36%.The average release rate of enteric-type Zn-gly in an acidic environment was 14.74%.At pH 6.8,the release rate at the first sampling was 78.78%,and the release rate at the third sampling was95.03%.The study was conducted on G.tilapia,the effects of supplementation of different zinc?Zn?compounds on growth performance,antioxidant properties,serum lipid content,trace elements concentration in liver and serum.When 40 mg/kg enteric-type ZnSO₄ and ZnSO₄ were used as the zinc source,the G.tilapia with an initial body weight of 47.47±0.29 g was used as the test object,and the samples were analyzed after 40 days of feeding.The results showed that compared with the control group and the ZnSO₄ group,the growth performance of the G.tilapia in the enteric-type ZnSO₄ group was increased,including the final body mass?P<0.05?,weight gain rate?P<0.05?and the protein efficiency?P<0.05?.In addition,the feed coefficient of the G.tilapia was significantly reduced?P<0.05?.The activities of alkaline phosphatase and superoxide dismutase in each group were not significantly changed?P>0.05?,while the total antioxidant capacity of the enteric-type ZnSO₄ group was significantly higher than that in other groups?P<0.05?.The total cholesterol and triglyceride levels in the enteric-type ZnSO₄group were significantly higher than those in the ZnSO₄ group and the control group?P<0.05?.The levels of zinc in the serum and liver of the enteric-type ZnSO₄ group were significantly increased?P<0.05?,and the ratio of copper to zinc in the liver is significantly reduced?P<0.05?.The results suggest that the addition of enteric-type ZnSO₄ to the feed can improve the growth performance and total antioxidant capacity of G.tilapia,increase the total cholesterol and triglyceride content in serum,increase the zinc content in serum and liver.When 40 mg/kg enteric-type Zn-gly,Zn-gly and ZnSO₄ were used as the zinc source,the G.tilapia with an initial body weight of 47.54±0.84 g was used as the test object,and the samples were analyzed after 40 days of feeding.The results showed that the weight gain rate and protein efficiency of G.tilapia in the enteric-type Zn-gly group were significantly higher than those in the control group and the ZnSO₄ group?P<0.05?,and the liver body specific index and feed coefficient were significantly decreased?P<0.05?,which is the group that promotes the best growth effect.The activities of superoxide dismutase and alkaline phosphatase in each group were not significantly changed?P>0.05?,and the content of malondialdehyde in the enteric-type Zn-gly group and the Zn-gly group was significantly lower than that in the control group?P<0.05?.The total cholesterol of the enteric-type Zn-gly group was significantly higher than that of the other groups?P<0.05?,and the triglyceride was significantly higher than the control group and the ZnSO₄ group?P<0.05?.The addition of different zinc sources in the diet had no significant effect on the contents of copper,iron and manganese in the serum?P>0.05?.The addition of enteric-type Zn-gly in the diet increased the zinc content in serum and liver,which was significantly higher than that of the control group and ZnSO₄ group?P<0.05?,and the ratio of copper to zinc in the liver is significantly reduced.The results suggest that the addition of enteric-type Zn-gly to the feed can improve the growth performance of G.tilapia,reduce the content of malondialdehyde,increase the total cholesterol,triglyceride content in serum and the level of zinc in serum and liver,moreover,the growth promoting effect of the enteric-type Zn-gly group may be better than that of the Zn-gly group...