饲料锌与维生素D3对草鱼生长和抗氧化性能的影响OA北大核心CSTPCD

To study the interactive effects of different zinc sources and levels with vitamin D3 on the growth performance,carcass trace element content,and antioxidant capacity of grass carp(Ctenopharyngodon idella),600 grass carp with a body mass of(25.86±0.13)g were selected.The experiment consisted of eight treatments(three replicates per treatment,25 fish per tank).Fish were randomly placed in 24 tanks with a volume of 900 L each.In this study,two factors and two levels of dietary vitamin D3(1000 and 2000 IU/kg),together with three levels of dietary zinc methionine(0,25,and 50 mg/kg),were designed.Treatment with 25 mg/kg zinc sulfate heptahydrate at two levels of dietary vitamin D3.Eight isonitrogenous and isolipidic diets were used in the 8-week growth trial.The eight treatment groups were named 1000D/Zn0(1000 IU/kgVD3+0 mg/kg zinc),1000D/ZnS25(1000 IU/kgVD3+25 mg/kg zinc sulfate heptahydrate),1000D/ZnM25(1000 IU/kgVD3+25 mg/kg zinc methionine),1000D/ZnM50(1000 IU/kgVD3+50 mg/kg zinc methionine),2000D/Zn0(2000 IU/kgVD3+0 mg/kg zinc),2000D/ZnS25(2000 IU/kgVD3+25 mg/kg zinc sulfate heptahydrate),2000D/ZnM25(2000 IU/kgVD3+25 mg/kg zinc methionine),and 2000D/ZnM50(2000 IU/kgVD3+50 mg/kg zinc methionine),respectively.Results showed that:(1)Dietary zinc levels and vitamin D3 had significant interaction effects on the weight gain rate(WG),feed conversion ratio(FCR),and protein efficiency ratio(PER)of grass carp(P<0.05).The 1000D/ZnM50 group exhibited the lowest FCR and the highest PER.Compared to the 1000D/ZnS25 group,the 1000D/ZnM25 group showed a significant decrease in FCR and a significant increase in PER(P<0.05).The WG of the 2000D/ZnM25 group was significantly increased(P<0.05).The PER of the 2000D/ZnM25 group was significantly higher than that of the 2000D/ZnS25 group,and the FCR was significantly lower than that of the 2000D/ZnS25 group(P<0.05).(2)No interactive effects exist between dietary zinc and vitamin D3 on copper,iron,manganese,zinc,and calcium in the carcasses of grass carp(P>0.05).The iron and calcium contents of grass carp carcasses in the 2000 IU/kg vitamin D3 group were significantly higher than those in the 1000 IU/kg vitamin D3 group.The iron content of grass carp carcasses in the ZnM25 and ZnM50 groups was significantly higher than in the Zn0 group.The zinc content increased with the increase in methionine zinc levels.The manganese content of grass carp carcasses in the ZnM50 group was significantly lower than that in the Zn0 and ZnM25 groups(P<0.05).(3)Interactive effects exist between dietary zinc levels and vitamin D3 on the activities of catalase(CAT),superoxide dismutase(SOD),AKP(alkaline phosphatase)and LZM(lysozyme)in the liver of grass carp.The interaction between zinc sources and vitamin D3 significantly affected LZM(P<0.05).The activities of CAT,SOD,AKP,and LZM in the livers of grass carp in the 2000D/ZnM25 group were significantly higher than those in the other groups,except for the 2000D/ZnM50 group,in which the MDA content was significantly reduced.Compared with the 2000D/ZnS25 group,the activities of CAT,AKP and LZM in the 2000D/ZnM25 group were significantly higher(P<0.05).These results indicated that the interactive effects of zinc and vitamin D3 in grass carp feed could significantly improve the growth performance and antioxidant capacity of grass carp.Under the conditions of this experiment,zinc methionine(25 mg/kg)and vitamin D3(2000 IU/kg)were more conducive to the growth and antioxidant capacity of grass carp,and zinc methionine was superior to zinc sulfate in terms of growth,feed utilization,carcass trace element content,and antioxidant capacity.