碩士 / 國立中山大學 / 海洋科學系研究所 / 104 / Previous studies have shown that cobia readily accept the diets containing high levels of lipid or carbohydrate. However, those studies only focus on lipid or carbohydrate when the experiments conducted. The utilization of diet high in lipid and carbohydrate levels needs further investigation. Considering the effect of feeding rate, fix feeding rate and feeding to apparent satiation, two feeding strategies were tested in this study. The aim of this study was to investigate the utilization of diet high in lipid and carbohydrate levels of the cobia, and the effects of diets on growth and body composition. The feeding trial in this study was composed by two stages, fish were fed 8 weeks each stage. All fish (36.09～39.32 g) were fed 3% body weight in stage 1. After sampling at the end of feeding trial, the rest of fish were remained and fed to satiation in stage 2. The experimental diets were isonitrogenous, five experimental diets were formulated with various levels of lipid (17%, 12% and 7%) and carbohydrate (20%, 15% and 10%)(L17 C10, L17 C15, L17 C20, L12 C20, L7 C20 and acclimation diet L7 C10). All fish were acclimated for 4 weeks before feeding trial began. In stage 1, the results indicated that the levels of dietary carbohydrate significantly affected survival, HSI, whole fish crude lipid and muscle crude lipid of the cobia when the diets contained 17% lipid, but there was no significant effect on PWG, SGR, FCR, PER and CF. The levels of dietary lipid significantly affected PWG, SGR, FCR, PER, HSI, whole fish crude lipid and muscle crude lipid when the diets contained 20% carbohydrate, but there was no significant effect on survival and CF. The results of stage 1 indicated that the levels of dietary lipid determine the growth performance of the cobia. To avoid reducing growth, the level of dietary lipid must be higher than 12% when the diets contain high level of carbohydrate. In stage 2, the results indicated that the levels of dietary carbohydrate significantly affected PWG and SGR when the diets contained 17% lipid, but there was no significant effect on survival, FCR, PER, HSI, CF and muscle crude lipid. The levels of dietary lipid did not significantly affect PWG, SGR, survival, FCR, PER, HSI, CF and muscle crude lipid when the diets contained 20% carbohydrate. The results of stage 2 indicated that the effects of diets changed along with feeding strategy, and feeding to apparent satiation caused negative effect on growth of the cobia. This study indicated that cobia accept the diet containing high levels of lipid and carbohydrate. Feeding cobia with diet high in carbohydrate and lipid levels at fix feeding rate provide some benefits, for example, reduce feed waste and maintain water quality.
| Identifer | oai:union.ndltd.org:TW/104NSYS5276023 |
| Date | January 2016 |
| Creators | Po-hao Chao, 趙柏豪 |
| Contributors | Houng yunn Chen, 陳宏遠 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 42 |
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