Effects Of Different Lipid Diets On Growth Performance And Physiological Functions And Fatty Acids Composition Of Juvenile Blunt Snout Brean (Megalobrama Amblycephala)

Experiment one: Effects of different lipid diets on growth performance and physiological functions and fatty acids composition of juvenile blunt snout brean (Megalobrama amblycephala)102 days experiment was carried out on juvenile blunt snout brean(7.77±0.18g) which is the peculiar herbivorous species of fish in China to study the effects of different lipid sources: Soybean oil, Rapeseed oil,Pig lard, Rapeseed and Carnitine Compound on growth performance and physiological functions and fatty acid composition in tissue to discuss the suitable lipid source and the law of fatty acid metabolize. 360 fish were average randomly feed in 24 standard cubic tanks with eight kinds of diets which contain and not contain Carnitine Compound.One:Effect on growth performanceThe results of SGR,FCR and PER show that juvenile blunt snout brean responded well to all the experiment diets,The type and quantity of fatty acid of four lipid sources can meet the demand for EFA on growth. The experiment indicates that C18:2n-6 and C18:3n-3 are essential fatty acid to juvenile blunt snout brean and C20:5n-3 are more important to experiment fish than C18:2n-6 and C18:3n-3. It will be adverse to feed fish with pig lard for long time because the pig lard caused high content of crude lipid in liver. Carnitine Compound promotes fat metabolism , added in the diets reduced the the size of visceral mass and volume of intestinal fat to a certain extent.Two:Effect on physiological functionParameter measured indicated that all the tested lipid source and the Carnitine Compound did not have apparent adverse effect on the health of the fish.Eight kinds of diets containing varying lipid sources had no significant effect on juvenile blunt snout brean.Three:Effect on fatty acid composition and metabolismThe fatty acid compositions of fish tissue lipids reflect those of the dietary lipids. The dietary lipids fatty acid affect fatty acid compositions of fish tissue .The pig lard and rapeseed group have greater effect on the fatty acid compositions of fish tissue lipids which have higher C18:1n-9/n-3 ratio than the soybean oil and rapeseed oil groups.Heart,brain,liver, spleen and serum were smaller affected by dietary fatty acids composition. But the kidney,muscle, intestinal fat, belly fat,intestinal and skin were greater affected. Both C18:2n-6 and C18:3n-3 can be converted to the long chain n-6 and n-3 HUFA in juvenile blunt snout brean. Carnitine Compound did not affect fatty acid type on liver lipid content.Experiment two:Fatty acid composition of five freshwater fishesFatty acids composition of Muscle,liver, kidney, intestinal,skin,belly fat, intestinal, brain and sex gland of five fishes which live in the same pool were measured to study the characteristic. The results show that the tissue of five kinds of fish have a higher MUFA content and lower PUFA content in the winter and low temperature, Fatty acids composition were affected by water temperature. At the same time,the fatty acids in tissue are transfer to sex gland. C20:5n-3 and C22:6n-3 content in tissue of silver carp are converted fromα-C18:3n-3 which content in fish food and the conversion is stronger than other four fish.Fatty acids composition in muscle have a smaller correlation with liver fatty acid composition.Internal organs also have a big development and utilization of the value...