Supplemental Effects Of Bile Acid And Cholesterol In Low Fishmeal Diets On Growth,Nutrient Utilization,Hepatopancreas Health Of Pacific White Shrimp(Litopenaeus Vannamei)

Bile acid has good emulsification and immunity-promoting effects,and cholesterol is an important nutrient for Pacific white shrimp,Litopenaeus vannamei.In the preparation of low fishmeal diet for shrimp,bile acid and cholesterol are the two important functional compounds needed to be considered.This study aimed to investigate the effects of adding bile acid and cholesterol in low fish meal diet on growth performance,nutrient utilization,total bile acid content,hepatopancreas health and antioxidant capacity of Litopenaeus vannamei.The results will provide a theoretical basis for the application of bile acid and cholesterol in shrimp feed,and direct the production of low fishmeal shrimp diet.Exp.1 Supplemental bile acids in low fishmeal diet improved the growth,nutrient utilization of Pacific white shrimpThis study was conducted to investigate the effects of adding bile acids to low fishmeal diet on the growth,nutrient utilization and serum biochemical parameters of Pacific white shrimp.First,a positive and a negative control diet were formulated to contain 200 g/kg fishmeal(FM20)and 140 g/kg(FM14),respectively.Then,bile acids were added to FM14 diet at the inclusion levels of 75(BA75),150(BA150)and 300(BA300)mg/kg.The five isoproteic and isolipidic diets were fed to shrimp with initial weight of 1.09 ± 0.01 g for 56 days.Compared to FM20 group,the weight gain(-12.9 %),body crude protein content,apparent digestibility of dry matter and protein,bile acid content in hepatopancreas and serum were decreased significantly,while feed conversion ratio(FCR)was increased by 0.17 in FM14 group(P < 0.05).The addition of bile acids to FM14 diet tended to increase the weight gain,body crude protein content,apparent digestibility of dry matter and protein(P > 0.05),reaching the similar levels to FM20 group(P > 0.05).Especially,the FCR of BA150 group was significantly lower(-0.16)than that of FM14 group(P < 0.05).Compared to FM14 group,the addition of bile acids(75–300 mg/kg)significantly reduced serum glutathione transaminase activity and increased alkaline phosphatase activity(P < 0.05).In addition,the supplementation of 300 mg/kg of bile acids significantly reduced serum glutathione transaminase activity and increased hepatopancreatic protease activity and serum bile acid content(P < 0.05).In conclusion,the addition of 150 mg/kg bile acids to low fishmeal diet(140 g/kg FM)could improve the growth performance and nutrient utilization of white shrimp.Exp.2 Effects of bile acid and cholesterol supplementation in low fishmeal diet on growth,nutrient utilization and hepatopancreas health of Litopenaeus vannameiIn experiment 1,it was found that adding bile acid in low fish meal diet could improve the growth performance of prawn,but the difference was not significant.Could cholesterol and bile acid in diet reach the same level as that in positive control group? This study was conducted to investigate the effect of adding bile acid and cholesterol to low fishmeal diet on growth,nutrient utilization,serum biochemical and antioxidative parameters of Pacific white shrimp.A positive and a negative control diet was formulated to contain 200 g/kg(FM20)and 100 g/kg(FM10)fishmeal,respectively.Then cholesterol(560 mg/kg),bile acid(150 mg/kg),cholesterol and bile acid(560 mg/kg+150 mg/kg)were added to the negative control diet,respectively.The five isoproteic and isolipidic diets were fed to shrimp with initial weight of 1.00 ±0.01 g for 56 days.Compared to FM20 group,the weight gain(WG),activities of lysozyme,protease and lipase,bile acid content in hepatopancreas and serum were decreased significantly,while feed conversion ratio(FCR),alanine aminotransferase,aspartate aminotransferase activities and malondialdehyde content was increased in FM10 group(P < 0.05).In FM10 group,the stellate structure of some hepatopancreas corpuscles disappeared,and the number of B and R cells decreased.The addition of bile acids and cholesterol to FM10 diet tended to increase the WG,amylase activity and bile acid content in hepatopancreas and hemolymph(P > 0.05).The combined supplementation significantly improved the growth performance,increased lipase and protease activities,and decreased FCR(P < 0.05).Compared to the FM10 group,the hepatic tubules returned to normal and the stellate structure became clear when cholesterol and bile acid were added in diet.In conclusion,the addition of bile acid and cholesterol in low fishmeal diet improved the growth performance,digestive ability and protect the health of hepatopancreas of Pacific white shrimp.Bile acids and cholesterol showed a synergistic effect.Exp.3 Effects of bile acid and cholesterol supplementation in fishmeal-free diet on growth performance and hepatopancreas health of Pacific white shrimpThis study was conducted to investigate the effect of adding bile acid and cholesterol to fishmeal-free diet on growth,hepatopancreas digestive enzyme activities,serum biochemical parameters,total bile acid,bile acid synthesis and transport-related gene expression of Pacific white shrimp.A positive and a negative control diet was formulated to contain 200 g/kg(FM20)and 0 g/kg(FM0)fishmeal,respectively.Then cholesterol(1120 mg/kg),bile acid(150 mg/kg),bile acid(300 mg/kg),cholesterol and bile acid(1120 mg/kg+150 mg/kg),cholesterol and bile acid(1120 mg/kg+300 mg/kg)were added to the negative control diets,respectively.The seven isoproteic and isolipidic diets were fed to shrimp with initial weight of 1.00 ± 0.01 g for 56 days.Compared to FM20 group,weight gain(WG),digestive enzyme activities,immune performance,total bile acid content in hepatopancreas and hemolymph,bile acid synthetase and bile acid transporter genes relative expression levels were significantly decreased in FM0 group,while feed conversion ratio(FCR),alanine aminotransferase,aspartate aminotransferase activities and malondialdehyde content were significantly increased(P < 0.05).In addition,atrophy and loose arrangement was observed in hepatopancreas corpuscles,and some of B and R cells disappeared in FM0 group.The addition of bile acids and cholesterol to FM0 diet tended to increase WG,total bile acid content bile acid synthesis and transporter genes expression,and the tissue structure of hepatopancreas,the number of B and R cells returned to normal.The combined supplementation of cholesterol and bile acid significantly increased the total bile acid content,CYP7A1,and acid phosphatase activities,promoted the activity of superoxide dismutase in hepatopancreas,and reduced the content of malondialdehyde in hepatopancreas and hemolymph(P<0.05).In conclusion,the addition of bile acid and cholesterol increased the total bile acid content in hepatopancreas and hemolymph,and tended to improve the growth performance.The combined addition of bile acid and cholesterol showed significant synergistic effect.