新型锌制剂对虹鳟生长及免疫功能的影响

为研究纳米锌及纳米锌多糖复合体对虹鳟生长及免疫功能的影响,选取平均体质量(120.0±3.0) g的虹鳟300尾,随机分成5组,每组3个平行,每个平行20尾,按1μL/g进行尾部肌肉注射纳米锌及纳米锌多糖复合体溶液,含量分别为1000、3000 mg/kg,试验周期为10 d。试验结果显示,纳米锌及纳米锌多糖复合体可不同程度提高虹鳟特定生长率(P>0.05)。1000 mg/kg纳米锌多糖复合体组虹鳟血液NBT阳性细胞数量百分比在第3 d最高,达22.3%(P<0.05);3000 mg/kg纳米锌多糖复合体组白细胞吞噬能力在第6 d最强(P<0.05)。3000 mg/kg纳米锌组虹鳟血清杀菌能力第3 d最高(19.4%),而3000 mg/kg纳米锌多糖复合体组血清杀菌能力第6 d最高,达32.43%(P<0.05)。第3 d,1000 mg/kg纳米锌多糖复合体组过氧化氢酶活性、一氧化氮合成酶活性分别为26.39、43.38 U/mL (P<0.05);第6 d,超氧化物歧化酶、酸性磷酸酶活性最高,分别为29.91 U/mL、201.4 U/L(P<0.05),微量丙二醛浓度最低,为3.19 nmol/mL。试验结束后通过杀鲑气单胞菌攻毒感染,7 d内观察虹鳟累积死亡率,1000 mg/kg纳米锌多糖复合体组累积死亡率仅30%。由试验结果可知,纳米锌和纳米锌多糖复合体均能对虹鳟免疫功能产生促进作用,以1000 mg/kg纳米锌多糖复合体效果最佳。

Effects of Nano-zinc and Nano-zinc-polysaccharide on Growth and Immunity in Rainbow Trout Oncorhynchus mykiss

A feeding trial was conducted to evaluate the effects of nano-zinc and nano-zinc-polysaccharide on growth and immune in rainbow trout(Oncorhynchus mykiss). Three hundreds individuals of rainbow trout with body weight of(120±3.0) g were randomly allotted to 5 groups(3 replicates and each 20 fish), and injected 1000, and 3000 mg/kg nano-zinc and nano-zinc-polysaccharide according to 1 μL/g body weight and fed a basal diet supplemented with nano-zinc and its polysaccharide for 10 days. The results showed that nano-zinc and nano-zinc-polysaccharide differently promoted the special growth rate(P<0.05). The percentage of NBT in the 1000 mg/kg nano-zinc-polysaccharide was increased by 22.3%(P<0.05) on the third day, with the maximal phagocytic percent in the 3000 mg/kg nano-zinc-polysaccharide on the sixth day. The serum bactericidal percent in the 3000 mg/kg nano-zinc was increased by 19.4%(P<0.05) on the third day, but that in the 3000 mg/kg nano-zinc-polysaccharide was increased by 32.43%(P<0.05) on the sixth day. The activities of catalase(CAT) and NOS in the serum of rainbow trout in the 1000 mg/kg nano-zinc-polysaccharide group were 26.39 U/mL and 43.38 U/mL(P<0.05) on the third day;the activities were 29.9 U/mL in SOD, 201.4 U/L in ACP, and content of 3.19 nmol/mL in MDA(P<0.05) on the sixth day. After the feeding trial, Aeromonas salraonicida injection challenged during 7 d was executed to test the effects of nano-zinc and nano-zinc-polysaccharide. There was mortality of 30% in the 1000 mg/kg nano-zinc-polysaccharide group. It is concluded that supplementation of nano-zinc and nano-zinc-polysaccharide can improve the immunity of rainbow trout, and that 1000 mg/kg nano-zinc-polysaccharide is the optimal dose.