The effects of feeding with two high energy diets ( high carbohydrate and high lipid) and the feeding regime of the two diets on growth, feeding conversion rate, and body composition of the cobia were studied. Based on the observation of lipid redistribution under dietary regime change in rats, this study was aimed to understand how regime change affects the tissue lipid content in the cobia. The study had three parts: preliminary experiment, experiment I, and experiment II. The preliminary experiment was designed to find the proper time to switch the high energy diets and to see the adaptation of cobia to the highe energy dietary treatments. The experiment I was conducted to monitor the growth and body composition of cobia fed for thirty-two days with different experimental diets, including control diets, high carbohydrate diets (HC), high lipid diets (HL), and different feeding regimes (HC¡÷HL: feeding the HC diet for the first sixteen days and the HL diet for the subsequent sixteen days; HL¡÷HC: feeding the HL diet for the first sixteen days and the HC diet for the subsequent sixteen days. The experiment II was studied serum concentration of glucose, triacylglycerol, and free fatty acids and tissues triacylglycerol concentration in liver and white muscle. The fish fed with the HC diet had higher body weight and lower feeding conversion rate than the HL group in first sixteen days; however, the growth of the two groups was not significantly different during the thirty-two day period. The lipid content of dorsal muscle was significantly higher in HC¡÷HL than that in HL¡÷HC; wherease, the lipid content of ventral muscle and viscera was not signficantly affected. The concentrations of serum triacylglycerol, free fatty acid, and relative mean ratio of triacylglycerol in muscle to triacylglycerol in liver were significantly affected. The results of relative mean ratio of serum TG to serum FFA and relative mean ratio of muscle TG to liver TG, suggest that high carbohydrate diet drives de nova lipid production in liver, which circulates to the peripheral tissues for storage as triacylglycerol. High lipid diet preferentially offers energy for lipolysis to produce energy. These results are consistant with the results in rats. Our results show that high energy diets provided a higher growth rate than the control diet, but there were no growth difference in cobia fed high carbohydrate diets, or high lipid diets, or between different feeding regimes. The cobia fed the high carbohydrate diet and the high lipid diet might use different ways for lipid accumulation. These fed the high carbohydrate diet had formed more triacylglycerol than that these fed high lipid diets. The feeding regime shift between the high carbohydrate diet and the high lipid diet significantly affect the the lipid content of the dorsal muscle in the cobia.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0813112-134451 |
| Date | 13 August 2012 |
| Creators | Hsu, Peng-Cheng |
| Contributors | Wei-Cheng Su, Houng-Yung Chen, Ruei-Liang Jhou, Chen-Chih Kao |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0813112-134451 |
| Rights | unrestricted, Copyright information available at source archive |
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