Effect Of Different Lipid Sources And Bile Acid On Growth Performance And Fatty Acid Composition In Macrobrachium Rosenbergii

This research was carried out to investigate the different combination and ratios of lipid sources as well as bile acid supplementation on growth performance, blood biochemical parameters and fatty acid composition in muscles and hepatopancreas of Macrobrachium rosenbergii, so as to provide evidence with respect to learning knowledge regarding fatty demands and metabolic laws in Macrobrachium rosenbergii.Experiment 1. 5 formulated diets with different sources of lipids (Ⅰ.fish oil 0.5%+soybean oil 2.5%,Ⅱ.fish oil 0.5%+rapeseed oil 2.5%,Ⅲ.fish oil 0.5%+peanut oil 2.5%,Ⅳ.fish oil 0.5%+linseed oil 2.5%,Ⅴ.soybean oil 1.5%+linseed oil 1.5%) fed Macrobrachium rosenbergii with average body weight 2.22±0.04g were conducted to investigate the effects of growth and common nutrients of tissues in either whole shrimps or muscles of Macrobrachium rosenbergii. The results indicated that the body weight gain in treatmentⅤwas higher than either treatmentⅡorⅢsignificantly(P<0.05); both body weight gain in treatmentⅠandⅣwas also greater than that in treatmentⅡ(P<0.05). The content of total moisture in whole shrimps in treatmentⅠwas the lowest among treatments and it was lower than that in eitherⅢorⅣobviously (P<0.05); the highest EE content in whole shrimps was recorded while receivingⅤtreatment(P<0.05); the CP content in whole shrimps in treatmentⅢwas lower than that in treatmentⅠ,Ⅱ,Ⅴrespectively(P<0.05); the total moisture content in muscles of treatmentⅣwas significantly higher than others(P<0.05). No significant difference was observed both for EE and CP in muscles between treatments(P>0.05). This study imply that different combination of lipid sources may influence growth performance and composition of body tissues in Macrobrachium rosenbergii.Experiment 2. 3 diets supplemented with the same ratios but varying in amounts of oils applied to Macrobrachium rosenbergii(Ⅰ.soybean oil 0+linseed oil 0%;Ⅱ. soybean oil 1.5%+linseed oil 1.5%;Ⅲ. soybean oil 3%+linseed oil 3%), to investigate the effect of different lipid levels on growth, blood biochemical indices as well as composition of body tissues in Macrobrachium rosenbergii. The results indicated: the growth rate in treatmentⅡwas greater than that in treatmentⅠsignificantly (P<0.05),no significant difference was observed in treatmentⅢ; the EE content both in whole shrimps and in muscles increased dramatically in accordance with elevated oil supplementation(P<0.05); the content of C18:2n6 in muscles and C18:3n3 either in muscles or in hepatopancreas increased, while the content of C20:5n3 and C22:6n3 decreased with increment of oils in diets respectively. We can speculate from this research that different lipid level in diets may take effects on growth performance, EE and PUFA in body tissues in Macrobrachium rosenbergii.Experiment 3. This experiment was carried out to evaluate the effects of different proportion of oils supplemented in diets on growth, blood biochemical indices as well as fatty acid composition in tissues of Macrobrachium rosenbergii. The five treatments were arranged as : soybean oil 3% + linseed oil 0% (Ⅰ); soybean oil 2%+ linseed oil 1% (Ⅱ); soybean oil 1.5%+ linseed oil 1.5%(Ⅲ); soybean oil 1%+ linseed oil 2%(Ⅳ); soybean oil 0%+ linseed oil 3%(Ⅴ). Trial periods lasted for 60d. The results showed that, both of the highest growth rate and lowest feed coefficient were achieved in treatmentⅣ(P<0.05); the EE content in whole shrimps was affected by addition of different soybean oil/linseed oil ratios in diets among treatments(P<0.05). the concentration of cholesterol and TG in blood inⅣwas significantly lower than the animals fed other diets(P< 0.05)..The relative content of C18:3n3 both in muscles and hepatopancreas increased along with elevated linseed supplementation in diets, while C18:2n6 decreased accordingly. We can dedicated from this research that different n-3/n-6 ratios may exert positive effects on growth performance, fatty acid composition in body tissues as well as cholesterol and TG level in blood in Macrobrachium rosenbergii.Experiment 4. This trial was conducted to study the effect of bile acid on growth, blood biochemical parameters and fatty acid composition in tissues by adding 0.1% bile acid to experimental diet comparing to control group in Macrobrachium rosenbergii. Results showed: the feed coefficient in experimental group was lower than control group significantly(P<0.05),no significant difference was observed for body gain rate(P>0.05); the EE content either in whole shrimps or in muscles was lower than control(P<0.05),the bile acid imposed positive effect on fatty acid composition in muscles, but no distinct effect observed in hepatopancreas. Furthermore, the content of PUFA and HUFA both for muscles and hepatopancreas decreased while employing bile acid in diet, conversely, the SFA and MUFA increased. This study mean that bile acid could be used to improve feed utilization and alter fatty acid composition in muscles of Macrobrachium rosenbergii.