| A series of experiments were conducted to investigate the application of several microalgae and probiotics on turbot(Scophthatmus maximus), based on microbiological, physiological, utritional and immunological methods. The results are summarized as followed:1. We conducted numbers of experiments to breed turbot fry effeciently, these experiments were performed by improving breeding establishments of turbot fry, disinfecting, controlling hatch density and breed density rationally, learning the best streamflow of water changing, controlling the quality of breeding water, feeding the burbot fry correctly. Now we have worked out a new pattern of turbot fry breeding and the result of our experiment are satisfactory. The experiment was performed using 1000g fertilized eggs, under the condition of that hatchability is 93%, we reared 205,000 healthy turbot fry of 6cm long, survival ratio is up to 22%.2. We also carried out the experiments to compare the breeding effects of using Nannochloropsis oculata and Isochrysis galbana to feed the juvenile turbot. We mainly compared the economic characters of turbot fry in 4 respects, body lenth,the albation rate,the deformity rate and the survival rate.3. A feeding experiment was conducted to investigate the effects of Bacillus.spp and microzymes on growth,intestinal bacterial flora and digestive enzyme activity of turbot.(1) Probiotics were used to fed turbot can promote the growth of turbot, feeding compound probiotics can significantly improve the survival rate of turbot and the specific growth rate (P <0.05). Composite probiotic groups have higher feed efficiency than in the control group, the compound group of Bacillus licheniformis + Bacillus subtilis + Lactobacillus acidophilus + Bifidobacterium was significantly different than the control group(P <0.05), the survival rate was significantly improve.(2) The number of total bacteria in the intestines of juvenile turbot by all groups added probiotics were not affected significantly (P> 0.05), but the total number of vibriones in the juvenile turbot intestinal tract were reduced (P <0.01).(3) Protein enzyme activity of the intestines of juvenile turbot were enhanced more or less by adding the supplement in different probiotics, and the compound group of Bacillus licheniformis + Bacillus subtilis + Lactobacillus acidophilus + Bifidobacterium was significantly different than the control group(P <0.05).(4) The lipase enzyme activity and the amylase enzyme activity in the intestinal tract were enhanced more or less by adding the supplement in different probiotics.(5) THC, PO, lysozyme activity, SOD and total antioxidant were enhanced more or less by adding the supplement in different probiotics. |
