饲料中不同类型的硒对仿刺参幼参生长和免疫指标的影响

Effects of dietary selenium sources on growth and immune indices in juvenile sea cucumber Apostichopus japonicus

在水温为13.0~20.0℃、盐度为31.0~32.0和pH为7.5的条件下,将初始体质量为5.36~5.57 g的仿刺参Apostichopus japonicus幼参放养在塑料水槽中（40 L）,每箱15头,分别投喂在基础饲料中添加0.4 mg/kg硒粉、富硒酵母、蛋氨酸硒和亚硒酸钠的试验饲料,以未添加硒的基础饲料作为对照组,每个试验组设3个重复。60 d的饲养结果表明：摄食添加硒饲料的仿刺参的增重率、体壁的粗蛋白含量和对饲料中粗蛋白的表观消化率均显著高于对照组（P〈0.05）,其中摄食添加蛋氨酸硒一组的仿刺参增重最大,摄食添加富硒酵母的次之;摄食添加硒饲料的仿刺参体腔液中超氧化物岐化酶（SOD）和过氧化氢酶（CAT）的活性均高于对照组,但差异不显著（P〉0.05）,而摄食添加酵母硒组的仿刺参体腔液中酸性磷酸酶（ACP）的活性显著高于对照组（P〈0.05）。饲料硒能促进仿刺参的生长,可能与提高饲料蛋白质的消化率有关;饲料硒能提高仿刺参的成活,可能与提高体腔中SOD、CAT和ACP的活性有关。试验表明,饲料中的有机硒能促进仿刺参对饲料蛋白质的消化和积累,进而促进其生长的效果优于无机硒。

Juvenile sea cucumber Apostichopus japonicus Selenka with initial body weight of 5.36- 5.57 g were stocked into 40 liter plastic tanks at a rate of 15 individuals per tank and fed the diets containing selenoyeast, sodium selenite, selenomethionine, or selenium powder at a rate of 0.4xl0-6selenium （without addition of selenium as control） with triplication at water temperature of 13.0-20.0℃, a salinity of31-32, and pH 7.5 for 60 days. The results showed that the sea cucumber fed the diets supplemented with selenium had significantly higher special growth rate than the animals fed the diets without supplementation of selenium did （P〈0.05）, the maximal body weight gain being observed in the sea cucumber fed the diets containing selenomethionine. There were no significant differences in the activities of superoxide dismutase （SOD）, and catalase （CAT） in the coelomic fluid of the sea cucumber between the treatment and the control groups. However, it was found that the acid phosphatase （ACP） in the coelomic fluid was significantly higher in the selenoyseast group than that in the control group, indicating that the selenium supplementation significantly improved the growth performance in the sea cucumber. Improvement of sea cucumber growth by supplementation of selenium was found to be attributed to the increase in digestibility of di- etary protein ; high survival of sea cucumber by supplementation of selenium was shown to be dependent on the high activities of SOD, CAT, and ACP in the coelomic fluid. There was better improvement of digestibility and retention of dietary protein, leading to higher special growth rate, by organic selenium than by inorganic selenium.