Effects of dietary probiotics on growth and digestive enzyme activities of juvenile Scophthal musmaximus

Experiments were conducted to determine the effects of different dietary administration of Probiotics on growth(SR: survival rate;SGR: special growth rate) and digestive enzyme activitis(including proteases、lipase and amylase) of Scophthal musmaximus.The initial body weight was(4.80±0.11),and the period of the experiment was 60 d.Basic diet was made of fish meal and defatted soybean meal as main protein sources.These juvenile turbots were fed with eight different diets: basic diet as control,and basic diet supplemented with 3.0×109CFU/g single probiotics(Bacillus subtilis,Bacillus licheniformis,Lactobacillus acidophilus,Bifidobacterium inopinatum) or 3.0×109CFU/g compound probiotics(B.licheniformis + B.subilis 1 : 1;B.inopinatum + L.acidophilus 1 : 1;B.licheniformis + B.subilis + B.inopinatum + L.acidophilus 1 : 1 : 1 : 1).Each diet was randomly fed to triplicate groups of 300 turbots reared in circulating water aquarium.The water temperature was 17℃±1℃ and the salinity was 32±0.2 during the experimental period.The results showed that turbot fed compound probiotics showed rela-tively higher growth rate compared with those fed control diet(P0.05).However,no significant differences in growth were observed between single probiotic groups and the control group.Diet with supplementation of probi-otics could improve the protease、lipase and amylase activities in digest tract of turbot,that is,the activities of protease was significantly higher in turbots fed the compound probitics(P0.05) than those in turbots fed control diet.The present results indicate that the diet with supplementation of probiotics can improve growth and digestive enzyme activities,and that compound probiotics groups show better effects than single probiotics groups.