The effects of dietary lipids on the growth and body
composition of young cobia,
Rachycentron canadum
Ho-shin Huang
Advisor¡GDr. Houng- Yung Chen
Institute of Marine Biology, National Sun Yat-sen University
Kaohsiung 804, Taiwan, ROC
Two experiments were conducted to study the effects of dietary lipid on the growth and body composition of young cobia , Rachycentron canadum. In the first experiment, cobia (mean body weight 69.67g) were fed fishmeal-based (contained 5% lipid) supplemented with 0, 5, 10, 15 and 20% oil mixture ( corn oil/ cod liver oil, 2:1) for 8 weeks. Results indicated that cobia fed diets containing 10% or 15% lipid had a significantly higher weight gain than those fed diets containing 5%, 20% or 25% lipid. Food conversion ratio (FCR) and protein efficiency ratio (PER) were better for fish fed the lipid diets containing 15% and 25% than those fed with 5% lipid diet. Regression analysis indicates that dietary lipid level for maximal growth of young Rachycentron canadum is about 14.6%. No significant changes were observed in hepatosomatic index. Changes in body composition were not significant with respect to ash and protein content of liver and muscle. High dietary lipid level caused a significant increase in the level in liver and muscle lipid. Aspartate transaminase (AST) was significantly higher for fish fed diets containing 20% and 25% than those fed with 5% and 10% lipid. Alanine transaminase (ALT) was significantly higher for fish fed diets containing 25% than those fed the other diets.
In the second experiment, Rachycentron canadum were fed fishmeal-based diets supplemented with lard oil, canola oil, corn oil, soybean oil, soybean + 1% DHA or cod liver oil. Fishmeal together with fish oil supplement contributed 8% lipid¡Fwhile the other oil sources were supplemented at 8% levels. Results show that fish fed diets with canola oil had a growth performance significantly lower than the other groups; while no difference was found among all other diets. The fish fed diets supplemented with corn oil, soybean oil or soybean + 1% DHA showed better food conversion ratio and protein efficiency ratio than the canola group. There was no difference among the canola, lard and fish oil groups. No significant changes were observed in hepato-somatic index. Liver lipid content was higher in fish fed diets with lard oil than fish fed other diets.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0628100-150209 |
| Date | 28 June 2000 |
| Creators | Huang, Ho-shin |
| Contributors | none, Houng yunn Chen, none, I Chiu Liao |
| 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-0628100-150209 |
| Rights | unrestricted, Copyright information available at source archive |
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