Effects of dietary Se on growth performance and activities of related enzymes in juvenile Japanese seabass Lateolabrax japonicus

Six levels of dietary Se were designed at 0.0 mg·kg~(-1), 0.2 mg·kg~(-1), 0.4 mg·kg~(-1), 0.6 mg·kg~(-1), 0.8 mg·kg~(-1) and 1.0 mg·kg~(-1) respectively and fed to juvenile Japanese seabass（Lateolabrazc japonicus） for 10 weeks. The initial body weight of seabass was （26.5±1.02）g. After 10 weeks experiment the fish were deprived of food for 24 h and then the GSH-Px activities in serum and liver, GR and GST activities in liver were analyzed and the growth performances were evaluated. The results indicated that in the treatment with diary Se at 0.4 mg·kg~(-1), seabass got the highest SGR and the lowest FCR, and the protein content in fish body was significantly higher than those in other treatments（P〈0.05）. The GSH-Px activities in serum and liver increased as dietary Se level raising from 0 to 0.4 mg·kg~(-1) and reached peak with Se level at 0.4 mg·kg~(-1), but when dietary Se level continued to raise from 0.8 mg·kg~(-1) to 1.2 mg·kg~(-1), the GSH-Px activities in serum decreased significantly（P〈0.05）. The highest GR activity in liver was observed in the seabass fed diet of Se level 0.4 mg· kg~(-1), and GR activities in liver decreased when diary Se level was 0.6 mg· kg~(-1).