草鱼膨化饲料中硫酸锌和蛋氨酸锌的应用效果比较研究

Comparative study on application effects of zinc sulfate and zinc methionine in expanded feed for Ctenopharyngodon idella

为研究膨化饲料中硫酸锌和蛋氨酸锌对草鱼(Ctenopharyngodon idella)生长、体成分、锌蓄积、血清生化和抗氧化的影响,实验选用初始体质量为(4.29±0.18)g的草鱼幼鱼480尾,随机分为4组(每组4个重复,每个重复30尾鱼),分别投喂4种饲料,在室内循环水养殖系统中养殖8周。对照组饲料(D1)不补充锌,另外三组饲料在对照组的基础上补充60 mg/kg不同形式的锌源,分别为硫酸锌组(D2)、蛋氨酸锌组(D3)、混合组(硫酸锌和蛋氨酸锌分别提供30 mg/kg锌,D4)。结果显示:(1)D2~D4组的生长性能和全鱼锌含量均显著高于D1组,且D2~D4组全鱼粗脂肪含量显著低于D1组,D2~D4组间的生长性能、全鱼体成分和锌含量均无显著差异。(2)D4组血清总蛋白含量和谷草转氨酶活性最高,其次为D2和D3组,D1组最低;D1组谷丙转氨酶活性最高;D4组的甘油三酯含量显著低于D1组。(3)D1组肝脏的CAT活性最低,MDA含量最高。(4)D1组肝脏细胞出现空泡、膜边界模糊、细胞核偏移,锌补充组肝脏形态明显改善。综上结果表明,在饲料中添加60 mg/kg(以锌元素计)硫酸锌、蛋氨酸锌或混合锌(以锌元素计1∶1)都可提高草鱼的抗氧化性能和健康水平,提高草鱼的生长性能;混合锌源对草鱼的健康作用效果更好。

A total of 480 juvenile Ctenopharyngodon idella with an initial body weight of(4.29±0.18)g were ran-domly allocated into four groups(four replicates per group;30 fish per replicate)and fed with four diets,re-spectively to assess the impact of zinc sulfate,zinc methionine,and their combination on growth,body com-position,zinc accumulation,serum biochemistry,and antioxidation in C.idella.The control diet(D1 group)contained no additional zinc supplementation.The other three diets contained 60 mg/kg of different forms of zinc compared to the control group:D2-zinc sulfate,D3-zinc methionine,and D4-a mixture containing 30 mg/kg each from the abovementioned sources.The results demonstrated that the growth performance and total zinc content in the D2-D4 group were significantly higher than those in the D1 group,and the crude fat con-tent in the D2-D4 group was significantly lower than that in the D1 group.There was no significant difference in growth performance,total body composition,and zinc content between the D2-D4 groups.Group D4 dis-played the highest serum total protein content and aspartate aminotransferase activity,followed by groups D2 and D3,with group D1 exhibiting the lowest levels observed.Group D1 also presented the highest alanine ami-notransferase activity among all analyzed groups.The CAT activity of the D1 group was significantly lower,while the MDA content was significantly higher than the other three groups.Hepatocytes in the D1 group exhib-ited vacuolation,blurred membrane boundaries,and nuclear migration,whereas zinc supplementation resulted in macroscopic improvements in liver morphology.In conclusion,our findings demonstrate that dietary sup-plementation with 60 mg/kg of zinc sulfate,zinc methionine,or mixed zinc can enhance antioxidant capacity and promote growth performance and health status in C.idella.Notably,mixed sources of zinc appear to confer superior health benefits on this species.