Dietary choline requirement of juvenile grass shrimp (Penaeus monodon)

Abstract

AbstractA feeding trial was conducted to determine the dietary choline requirement of juvenile grass shrimp, Penaeus monodon. Purified basal diets were formulated using vitamin-free casein (containing 370 mg choline per kg) as the protein source. Graded levels (0, 300, 600, 1000, 2000, 4000, 7000, and 10 000 mg choline per kg diet) of choline chloride were added to the basal diet, resulting in eight dietary treatments in the experiment. Each diet was given to three replicate groups of shrimp initially averaging 1·18 (s.d. 0·01) g for 8 weeks. Weight gain was highest in shrimp given the diets supplemented with 7000 and 4000 mg choline per kg diet, followed by the groups given 2000 mg/kg, then 1000 and 600 mg/kg, and finally 300 mg/kg and the unsupplemented control group (P < 0·05). Shrimp given diets supplemented with 7000 and 4000 mg choline per kg diet had significantly higher food efficiency and survival than those given diet with 300 mg choline per kg or the control diet. Higher body crude protein and choline concentrations were recorded in shrimp given diets supplemented with 4000 and 7000 mg choline per kg diet than shrimp given diets with ≤600 mg choline/kg and ≤2000 mg choline per kg, respectively. Analysis by polynomial regression of weight gain and body choline concentration for P. monodon gave a maximum at about 6000 mg/kg. Taking into account the choline concentration of the unsupplemented basal diet, the optimal dietary choline requirement for growing P. monodon is about 6200 mg/kg.