碩士 / 國立屏東科技大學 / 水產養殖系所 / 102 / In order to evaluate whether Schizochytrium sp. algae meal can be used as a docosahexaenoic acid (DHA) source and the algal meal or its oil can replace fish oil in diet for grouper, the study was to investigate the effects of algal meal on growth, fatty acid profile, physiological and immune responses. In Experiment 1, three experimental diets including all fish meal (F), fishmeal replacement by 20% soybean meal (FS) and FS supplemented with 5% algal meal (FS+5%), were each fed to triplicate groups of fish (initial wt: 3.38 ± 0.04 g) in a recirculating system for 8 weeks. There were no significant differences in weight gain, condition factor, survival and hematocrit among all dietary treatments. Fish fed the FS+5% diet had higher (P < 0.05) red blood cell (RBC) count and hemoglobin (Hb) concentrations than fish fed FS diet. Whole body DHA and eicosapentaenoic acid (EPA) concentrations were higher in fish fed the FS+5% diet than those in other dietary treatments. DHA deposition was the highest in the FS group, followed by F group, and the lowest in FS+5% group. The results showed that grouper can utilize algal meal as a DHA source without negative effects on growth. In Experiment 2, six experimental diets including all fish meal (F) and replacement 40% protein by soybean meal (FS) as controls, fish oil replaced by algal meal (DM) or oil (DO) providing a DHA/EPA ratio of 1.5 (DM, DO) and 2.5 (DM2.5, DO2.5), were each fed to triplicate groups of fish (initial wt: 8.48 ± 0.06 g) in a recirculating system for 8 weeks. Whole body proximate composition, hematological and immune responses, were not affected by dietary treatments. Grouper fed the DO2.5 diet had higher weight gain than fish fed the diet FS group. Whole body and muscle DHA concentrations approximately increased by increasing dietary DHA level. Both parameters was higher in fish DO2.5 diet group but lower in DM group than other dietary groups. Hepatic DHA concentration was higher in fish fed the DO2.5 diet than other dietary treatments. DHA deposition was the lowest in DM and DM2.5 groups, followed by DO2.5 group, then the FS group, and the highest in F and DO group. The results demonstrated that grouper can utilize algal meal or oil as DHA source. The efficiency of algal oil is better than that of algal meal. Our results also indicated growth of grouper was depressed by replacing 40% fish meal by soybean meal and improved by increasing DHA/EPA ratio.
| Identifer | oai:union.ndltd.org:TW/102NPUS5086001 |
| Date | January 2014 |
| Creators | Zhuo, Li-Chao, 卓立超 |
| Contributors | Lin, Yu-Hung, 林鈺鴻 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 87 |
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