The Effect Of Different Oils And Different Levels Of Phospholipids On The Growth And Fatty Acid Composition Of Yellow Catfish, Pelteobagrus Fulvidraco

Two trials were carried out to evaluate the effect of different oils and different dietary phospholipids levels on the growth, survival rate and body fatty acid composition. Six diets with different dietary lipid and four diets with different phospholipids levels were formulated and fed twice a day to P. fulvidraco juvenile cultivated in 72cm X 45cm ?0cm plastic tanks. Each diet was triplicates. Each tank contains 60 juvenile with average initial body weight of 3.2 g. Trial lasted for 8 weeks. Sampling took out at the end of every two weeks. Meanwhile body weight was measured. Fatty acid compositions were analyzed with Shizima GC-9A gas chromatography. The main results are shown as follows.l.The effect of different oil and different levels of phospholipids on the growth and survival of yellow catfish is not significant. There were no deaths during the feeding period in both trials. No significant difference was observed in the weight gain rate and specific growth rate of yellow catfish fed with diet containing different oils. The feed conversion ratio was significantly higher in fish oil group than in soybean oil group, and the rest showed no significant difference. The weight gain and specific growth rate improved as the phospholipid content increased. But there were no significant differences among the four groups fed with diet containing different phospholipids levels. No significant difference was observed in feed conversion ratio among the four groups.2.The fatty acid composition of yellow catfish was influenced by the dietary fatty acid composition. To the fish groups fed with diet containing different oils, the HUFA content in muscle and viscera of yellow catfish in fish oil group was significantly higher than other groups (P<0.05), while the HUFA content in the other two groups fed with diets containing fish oil (fish oil-soybean oil group and fish oil-pig oil group) are higher but not significantly than in those groups without fish oil. 18C:2n-6 content in muscle and viscera was significantly higher in soybean oil group (P<0.05), while the content of this fatty acid in the other two groups fed with diets containing soy bean oil (fish oil-soybean oil group and soybean oil-pig oil group) are higher but not significantly than in those groups without soybean oil. The fish of pig oil group had highest saturated fatty acids (SFA), lowest HUFA, and low poly-unsaturated fatty acids. To the fish groups fed with diet containing different phospholipids levels, in the viscera, 18C:2n-6, 18C:3n-3, 20C:5n-3, and HUFA content of the 6% phospholipid groug were significantly higherthan the other groups. To 22C:6n-3 and HUFA content, the 6% and 4% phospholipid groups were significantly higher. As the hospholipid content decrease, DHA decreased. In the muscle, the difference of the fatty acids content was smaller among the three fish groups fed hospholipids. But the difference was larger between the three groups and the fish group fed no hospholipids.3.The main chang of the fatty acid composition of P. fulvidraco happened during thefirst two weeks after they were fed with the diets.4.The variation range of every fatty acid in the diets was obviously larger than that their ranges in the fish. This suggested P. fulvidraco could maintain relatively stable fatty acid composition in their body.5.The muscle and the viscera had nearly the same SFA content. But MUFA content was lower and PUFA content higher in the muscle than in the viscera. The HUFA content of the muscle was approximately twice as that in the viscera.