Growth Performance, Feed Utilization, Proximate and Fatty Acid Composition, Rna/Dna Ratios, Lpl and Myod Expression of Nile Tilapia (Oreochromis Niloticus) Fed Elevated Levels of Palm Oil

摘要

　　A feeding trial was conducted to establish the effect of dietary palm oil levels on growth performance，feed utilization，body composition，plasma metabolites，and fatty acid profile of whole body and muscles as well LPL and MyoD expressions and DNA/RNA ratio in the muscle of Oreochromisniloticuswith an initial weight of 11g for 8 weeks. Five isonitrogenous diets，32％ crude protein with increasing palm oil levels of 0% (Control，CTRL)，2%，4%，6% and 8% were used as the major lipid source for the trial. The results showed that highest values of weight gain，specific growth rate，and protein efficiency ratio occurred at 6% dietary palm oil level. Proximate analysis showed lipid，moisture，ash and crude protein content in both the whole body and muscle were significantly (P<0.05) affected by different palm oil levels. Plasma triglycerides，cholesterol and total protein were significantly affected by elevated palm oil levels. Fish fed 8%palm oil levels recorded triglyceride values significantly higher than the CTRL group. Unlike fish fed 2%，the total protein values recorded for fish fed 4%，6%and 8%were significantly higher than that of the CTRL group. Also fish fed 6% and 8% recorded cholesterol values that were significantly higher than the CTRL group. Furthermore，total saturates，total n-3 poly unsaturated fatty acids (PUFA)，total n-6 PUFA as well as DHA/EPA fatty acids were significantly affected. Fish fed the 6%palm oil level had the highest value of n-3/n-6 ratio as well as DHA/EPA ratio among all treatments. Fish fed the 6%palm oil level recorded the highest level of docohexanoic acid (DHA) in whole body and was significantly higher than that of the control. In addition，the results showed that RNA，DNA contents as well as ratio of RNA to DNA were significantly affected (P<0.05)，in each case the highest was recorded in fish group subjected to 6%palm oil level. There was a strong positive correlation between nucleic acid concentration (RNA concentration and RNA:DNA ratio) and specific growth rate (SGR)，protein efficiency ratio (PER)，while a negative correlation existed between nucleic acid concentration (RNA concentration and RNA:DNA ratio) and feed conversion ratio (FCR). The expressions of LPL and MyoD in muscle were not significantly affected by the different palm oil levels，although the highest expression was observed in fish fed with 6% palm oil level. There also existed a strong positive correlation between the expression of LPL，MyoD and SGR，PER whiles their correlation with FCR was negative. In conclusion，elevated palm oil affected the RNA，DNA concentrations as well as RNA/DNA ratio significantly although the expression of LPL and MyoD were not affected significantly by elevated palm oil levels. In conclusion，the results showed that elevated palm oil levels affect growth performance，feed utilization and body composition of O. niloticus. Also，the results clearly showed that the RNA，DNA concentration as well as RNA/DNA ratio in O. niloticus muscle were significantly affected by diets containing elevated palm oil levels. Also the diet containing 6%palm oil level induced the highest expression of LPL and MyoD，although there was no significant difference among different palm oil levels. The present study documents that 6% palm oil under similar rearing conditions is best for rearing O. niloticus.

目录

封面

声明

英文摘要

List of Abbreviation

目录

1. Introduction

1.1 General introduction

1.2 Qualities of palm oil

1.3 Availability of palm oil

1.4 Price of palm oil

1.5 Effect on feed quality

1.6 Effect on growth performance and body composition

1.7 Background of Nile tilapia (Oreochromisniloticus)

1.8 The purpose of this research

2 Growth performance, feed utilization, body and fatty acid composition of Nile tilapia (Oreochromisniloticus) fed elevated levels of palm oil

2.1 Introduction

2.2 Materials and methods

2.3 Results

2.4 Discussion

2.5 Conclusions

3 RNA/DNA ratio and LPL and MyoD expressions in muscle of Oreochromisniloticusfed with elevated levels of palm oil

3.1 Introduction

3.2 MATERIALS AND METHODS

3.3 RESULTS

3.4 DISCUSSION

3.5 CONCLUSION

参考文献

Published papers

致谢