碩士 / 國立臺灣海洋大學 / 水產養殖學系 / 93 / Abstract
Two experiments were conducted to investigate the effects of different dietary soya lecithin levels on the growth and body composition of cobia, Rachycentron canadum. In first trial, triplicate groups of cobia (3.4±0.2g initial body weight)were fed five isonitrogenous and isoenergetic diets. Fish meal was used as dietary protein,Five isonitrogeneous and isoenergetic diets containing 8% cod liver oil / corn oil (2:1, w/w) with soya lecithin ranging from 0 to 40g/kg in 10g/kg increment were evaluated. After 6 weeks experimental trial, cobia fed 30g/kg soya lecithin had the highest weight gain (1244.5%), there is no significant difference in weight gain which cobia fed diets containing 20 and 30g/kg soya lecithin. Hepatic index ranged from 2.89 to 3.21. Survival rate for all treatments were above 93%. The moisture, ash of cobia muscle were not significant difference among all treatments. The crude lipid of cobia was increased with dietary soya lecithin level. The muscle tissue of crude protein of cobia had a negative correlation with those of crude lipid of cobia. The crude lipid of cobia liver increased with increasing dietary soya lecithin. The neutral lipid of cobia muscle had high levels of 16:0, 18:1n-9 and 18:2n-6. The major fatty acids of polar lipid of cobia muscle were 16:0, 18:1n-9, 18:2n-6 and 22:6n-3. The 18:2n-6 of muscle tissue increased with increasing dietary soya lecithin level. The neutral lipid of cobia liver fed diets containing soya lecithin had high concentration of 16:0, 18:1n-9 and 18:2n-6. The 18:2n-6 of liver tissue increased with increasing dietary soya lecithin. The major fatty acids of polar lipid of cobia liver were 16:0, 18:0 and 22:6n-3. Cobia fed 30g/kg soya lecithin had the highest 22:6n-3 contention.
In the second trial, triplicate groups of cobia (3.4±0.1g initial body weight) were fed diets 0.5% carnitine supplemented containing two lipid levels (8% and 15%) with five lecithin levels (0, 1, 2, 3 and 4%). After 6 weeks experimental trial, cobia fed 15/0 treatment had best weight gain (829.7%), the intermediate was cobia fed 15/10 treatment. Cobia fed diets 15/30 and 15/40 were not significantly difference in weight gain and significantly low than those fed other treatments. Hepatic index ranged from 3.13 to 4.42. Survival rangedfrom 93.3% to 100%. The neutral lipid of cobia muscle had high concentration of 16:0, 18:1n-9 and 18:2n-6. Cobia fed 15/0 diet had the highest 16:0 and 18:1n-9. Cobia fed 8/40 diet had the highest 18:2n-6. The major fatty acids of polar lipid of cobia muscle were 16:0, 18:1n-9, 18:2n-6 and 22:6n-3. Cobia fed 8/40 diet had the highest 18:2n-6. The neutral lipid of cobia liver had high concentration of 16:0, 18:1n-9 and 18:2n-6. Cobia fed 8/40 diet had the highest 18:2n-6. The major fatty acids of polar lipid of cobia liver were 16:0, 18:0 and 22:6n-3. Cobia fed 8/0 diet had the highest 22:6n-3.
| Identifer | oai:union.ndltd.org:TW/093NTOU5086026 |
| Date | January 2005 |
| Creators | Yi-Ming Lui, 呂羿旻 |
| Contributors | Sheen Shyn-Shin, 沈士新 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 70 |
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