Choline requirements of grass shrimp(Penaeus monodon)as affected by dietary lipid level

Abstract

AbstractA feeding trial was conducted to determine the adequate level of dietary choline for juvenile grass shrimp, Penaeus monodon, given diets containing different dietary lipid concentrations. Purified diets with six levels of choline chloride (0, 2000, 5000, 8000, 11000 and 14000 mg/kg diet) at either 50 or 110 g/kg lipid concentration were each given to three replicate groups of 15 shrimp (mean weight: 0·88 (s.d. 001) g) for 8 weeks. Results indicated that in the 50 g/kg lipid group, weight gain was highest in shrimp given the diets supplemented with 5000 mg choline per kg diet, intermediate in the group given 8000 mg choline per kg diet and lowest in the 14000 mg choline per kg diet and the unsupplemented control groups (P < 005); food efficiency (FE) was highest in shrimp given 5000 mg choline per kg diet, followed by the groups given > 8000 mg choline per kg diet and lowest for the unsupplemented control group. In the 110 g/kg lipid group, weight gain was highest in shrimp given the diets supplemented with 5000 and 8000 mg choline per kg diet, intermediate in the groups given 2000 and 14000 mg choline per kg diet and lowest in the control group; FE was higher in shrimp given 8000 mg choline per kg diet than in any of the other dietary groups; hepatic lipid concentration was higher in shrimp given < 2000 mg choline per kg diet than shrimp given > 5000 mg choline per kg diet. In both lipid groups, shrimp given < 2000 mg choline per kg diet had higher hepatosomatic index (HSI) than shrimp given > 5000 mg choline per kg diet. Of shrimp given <2000 mg choline per kg diet, those in the 110 g/kg lipid group had higher HSI and hepatic lipid concentration than those in the 50 g/kg lipid group. Analysis by polynomial regression of weight gain indicated that the optimum dietary choline requirements in juvenile grass shrimp were about 6400 mg/kg diet and 7800 mg/kg diet in 50 and 110 g/kg lipid diets, respectively.