本试验在刺参（Apostichopus japonicus）基础饲料中梯度添加酵母硒，研究其对刺参生长、抗氧化能力及夏眠前后刺参体壁硒含量的影响。试验在室内500 L的水槽中进行，以2龄刺参[初始体重为（140.00±0.21） g]为研究对象，随机分为5组，在基础饲料中分别添加不同水平[0（对照）、0.5、1.0、1.5和2.0 mg/kg]的酵母硒（饲料中总硒含量实测值依次为0.40、0.94、1.55、2.08和2.40 mg/kg），每组3个平行，每个平行放养11~14头刺参，每日投喂2次至表观饱食。试验共分为2个阶段，共计105 d。第1阶段：进行45 d的富硒饲料的饲养，待试验结束后测定增重率、抗氧化能力和体壁中硒的含量；第2阶段：于刺参夏眠结束后（有少量摄食及明显活动迹象即为夏眠结束，刺参室内夏眠期为60 d）进行取样，测定体壁中硒的含量。结果表明：1）随着饲料中酵母硒添加水平的提高，刺参生长和抗氧化能力均表现出先升高后下降的趋势。当饲料中添加0.5 mg/kg的酵母硒时，刺参的增重率具有最高值，且显著高于1.0 mg/kg组（P<0.05），但与其他各组差异不显著（P>0.05）。刺参体腔液中超氧化物歧化酶（SOD）、谷胱甘肽转移酶（GSH-ST）、谷胱甘肽过氧化物酶（GSH-Px）活性及总抗氧化能力（T-AOC）随酵母硒添加水平的升高而下降，其中0.5 mg/kg组SOD、GSH-Px、GSH-ST活性与对照组相比无显著差异（P>0.05），但均显著高于2.0 mg/kg组（P<0.05）；0.5 mg/kg组丙二醛（MDA）含量与1.0 mg/kg组之间无显著差异（P>0.05），但显著高于其他3组（P<0.05）；0.5 mg/kg组过氧化氢酶（CAT）活性显著高于对照组（P<0.05），但与其他3组无显著差异（P>0.05）。2）夏眠前后，刺参体壁中硒元素的富集随着饲料中酵母硒添加水平的增加而显著升高（P<0.05）。与夏眠前相比，刺参夏眠结束后各组刺参体壁硒含量较夏眠前均呈现不同程度的衰减，但仍有50%以上的保留率，在1.0 mg/kg组中刺参夏眠结束后体壁中硒的保留率最低，为51.12%，在2.0 mg/kg组中硒的保留率最高，为91.38%。综上，饲料中添加0.5 mg/kg的酵母硒可以提高刺参的生长性能、抗氧化能力及体壁中硒的含量，而中高剂量（1.0~2.0 mg/kg）的酵母硒会降低刺参的增重率和抗氧化能力，虽然夏眠结束后刺参体壁中硒的含量均有衰减趋势，但各组均达到富硒刺参标准（水产动物富硒标准为硒元素含量为0.5~1.0 mg/kg）。

This experiment was conducted to investigate the effects of adding selenium yeast (SY) in a basal diet on the growth performance, antioxidant capacity and selenium content in the body wall before and after the aestivation of Apostichopus japonicus. This experiment was carried out in 500 L plastic tanks. Two-day-old Apostichopus japonicus with an initial body weight of (140.00±0.21) g were divided into 5 groups, which fed the basal diet with SY at 0, 0.5, 1.0, 1.5 and 2.0 mg/kg (the measured total selenium contents in diets were 0.40, 0.94, 1.55, 2.08 and 2.40 mg/kg, respectively), and each group had 3 replicates, each replicate had 11 to 14 Apostichopus japonicas. Apostichopus japonicus were fed twice daily to apparent satiety. The experiment included two phases, and total 105 d. The phase 1: the feeding experiment lasted for 45 days, at the end of the feeding experiment, weight gain rate, antioxidant ability and selenium content in body wall were detected; the phase 2: at the end of aestivation (there is a small amount of intake and obvious signs of activity; aestivation lasted for 60 d), body wall were sampled for the detection of selenium content. The results showed as follows: 1) with the increase of SY supplementation, growth and antioxidant ability of Apostichopus japonicas increased firstly and then decreased. When the SY supplementation was 0.5 mg/kg, the weight gain rate was the highest, and significantly higher than that in 1.0 mg/kg group (P<0.05), but had no significant difference compared with other groups (P>0.05). The activities of superoxide dismutase (SOD), glutathione transferase (GSH-ST), glutathione peroxidase (GSH-Px) and total antioxidant capacity (T-AOC) showed decreasing trend with the increase of SY supplementation, and the activities of SOD, GSH-Px and GSH-ST in 0.5 mg/kg group had no significant difference compared with the control group (P>0.05), but were significantly higher than those in 2.0 mg/kg group (P<0.05); the content of malonaldehyde (MDA) in 0.5 mg/kg group had no significant difference compared with 1.0 mg/kg group (P>0.05), but was significantly higher than that in other three groups (P<0.05); the activity of oxidase (CAT) in 0.5 mg/kg group was significantly higher than that in control group (P<0.05), but had no significant difference compared with other three groups (P>0.05). 2) The selenium content in the body wall of Apostichopus japonicus showed an increasing trend with SY supplementation increased before and after the aestivation. Although the selenium content in the body wall was decreased after aestivation, the selenium retention rate was still above 50% in all groups. The selenium retention rate in 1.0 mg/kg group was the lowest, which was 51.12%, and that in 2.0 mg/kg group was the highest, which was 91.38%. It can be concluded that the supplementation of 0.5 mg/kg SY in the diets can enhance the growth performance, antioxidant capacity and selenium content in the body wall, while middle and high supplementation levels of SY (1.0 to 2.0 mg/kg) can decrease weight gain rate and antioxidant capacity, although the selenium content in the body wall have an decreasing trend at the end of aestivation, all the groups reached the standard of selenium-enriched Apostichopus japonicas (aquatic animal selenium-enriched standard is 0.5 to 1.0 mg/kg selenium).