Effects Of Different Fat Sources On The Growth And Reproductive Performance Of Procambarus Clarkii

Procambarus clarkii is an important aquatic product of freshwater shrimp in China.In this study,the effects of palm-oil,fish oil and soybean oil on the growth performance,serum physiology and biochemistry,tissue routine composition,reproductive performance and fatty acid composition of protocrayfish were studied by adding different fat sources with total lipid of 7% into the feed of protocrayfish.Objective to find a suitable fat source to promote the growth and reproductive performance of procambarus crustaceans.Experiment with casein and gelatin as protein source,compound 6 groups such as nitrogen,such as lipid feed,respectively palm oil: fish oil:soybean oil 6:0:0?4:1:1?2:2:2?0:3:3? 0:6:0 ?0:0:6.The experimental shrimp came from Chongming base of Shanghai ocean university.The initial specification of the experimental shrimp was 5.26 � 0.10 g.Before the start of the experiment,commercial feed was fed to the circulat tank for 2 weeks.The experiment was divided into 6 groups with 3 replicates in each group,with 14 shrimp in each repetition.A total of 42 shrimp in each group were selected.The experiment was divided into two breeding stages: growth stage and pro-shrimp breeding stage.The 16 weeks of cultivation were the growth stage.Then,each shrimp was weighed,body length and width were measured,and survival rate was recorded.During the 17 weeks of culture management,the reproductive performance and hatching rate were evaluated.After the experiment,the body weight of each shrimp was weighed,the shell length and the width were measured and recorded.Then vivisection was performed to extract serum,hepatopancreatine,gonadal and muscle,and to calculate indexes such as hepatopancreatine index(HSI)and gonadal index(GSI).The collected fresh tissues were stored in the refrigerator at-20? for the determination of biochemical and tissue fatty acids.After the serum was centrifuged,the supernatant was stored at-40? for the determination of enzyme activity.The main research results are as follows: 1.Growth performance and body composition: in this experiment,Diet 4 had the best effect on the weight gain,body length growth and specific growth rate of Procambarus clarkii.There was no significant difference in hepatopancreatine index(HSI)between the groups(P < 0.05).The survival rate in Diet 1 was the lowest(P < 0.05),and the increase of palm-oil supplementation level showed a decreasing trend.There was no significant difference in the effects of water,ash and crude fat in muscle between each group(P > 0.05),and the crude protein content was the highest in the Diet 5(P < 0.05).There was no significant difference in hepatopancreas water and ash content in each group(P > 0.05),and the levels of crude protein and crude fat were the highest in Diet 1,Diet 5 and Diet 6(P < 0.05).2.Effects of fatty acid composition in tissues: fatty acids in muscles are mainly C16:0,C18:1n9,C18:2n6 and C20:5n3.The proportion of MUFA increased significantly with the increase of palm oil supplement level(P < 0.05),and the change trend of sigma n-6PUFA was consistent with the change trend of the content in the corresponding feed,which was the highest in the soybean oil Diet 6 and the lowest in the Diet 5,with a significant difference(P < 0.05).The relative content of LC-PUFA and the ratio of n-3/ n-6 increased significantly compared with that of the group,which was the highest in Diet 5(P < 0.05)and the lowest in Diet 6(P < 0.05).Fatty acids in the liver and pancreas.3.Serum physiological and biochemical indicators: the content of triglyceride(TG)in the serum was the highest in the Diet 1,which was significantly different from the Diet 2? 5(P < 0.05).The contents of high-density lipoprotein cholesterol(HDL-C)and lowdensity lipoprotein cholesterol(LDL-C)were significantly lower in the Diet 1(P < 0.05).The total antioxidant capacity(T-AOC)increased significantly with the increase of the proportion of fish oil added(P < 0.05),and was the highest in the Diet group(P < 0.05).Superoxide dismutase(SOD),alkaline phosphatase(AKP)and acid phosphatase(ACP)had the highest activity in Diet 5(P < 0.05).The activity of acid phosphatase(ACP),glutamate transaminase(GOT)and glutamate transaminase(GPT)was the highest in Diet 3(P < 0.05),and the lowest in Diet 6(P < 0.05).4.Reproductive performance index: the maturity rate of pro-shrimp in Diet 3 and Diet 4 was the highest about 78%;the performance increased first and then decreased with the increase of fish oil in the feed,and the maturity rate was the lowest in Diet 1 and Diet 6.The effect of Diet 1?Diet 3 with palm oil was poor in promoting the yield of shrimp.The effect of Diet 4 on the spawning rate of pro-shrimp was obvious,but the effect on the hatching rate was poor.There was no significant difference between different fat sources on the egg diameter and fecundity of oviposition(P > 0.05),the number of oviposition was the lowest in Diet 6(P < 0.05),and the reproductive index was the highest in Diet 1(P < 0.05).5.Composition of fatty acids in the gonads: the relative content of saturated fatty acids(SFA)was the highest in Diet 1,Diet 2 and Diet 3,and the relative content of c16:0 was the highest in Diet 1(P < 0.05).The high ratio of monounsaturated fatty acids MUFA is 36.9%?55.37%,mainly in C18-1n9.The ratios of C20:4n6,C20:5n3 and C22:6n3 in the gonads increased with the increase of the level of fish oil,and n-3/n-6 was the lowest in Diet 1 and Diet 6(P < 0.05).The ratio of DHA/EPA ranged from 0.22 to 0.24,which was the lowest in Diet 2 and Deit 3 and significantly different from other groups(P < 0.05).