UTILIZATION OF CHOLINE IN DIFFERENT LEVELS AND DIETARY CHOLINE AVAILABILITY VALUES IN SEVEN COMMON FEED INGREDIENTS FOR JUVENILE BLUNT SNOUT BREAM, MEGALOBRAMA AMBLYCEPHALA

To evaluate dietary choline availability values in juvenile blunt snout bream Megalobrama amblycephala, an 8-week feeding trial was conducted with seven common feed ingredients. Choline chloride was fortified to the basal diet that contained 310 g/kg diet from vitamin-free casein and gelatin to formulate four purified diets containing 0, 1030, 1230 and 1430 mg/kg choline, respectively. These four purified diets were used to generate a standard curve to evaluate choline availability in seven diets containing the following common feed ingredients: fish meal (FM), soybean meal (SBM), rapeseed meal (RSM), cottonseed meal (CSM), wheat middling (WM), wheat bran (WB) and rice bran (RB). The choline in seven diets was 1230 mg/kg including 1030 mg/kg choline chloride. Three groups of Megalobrama amblycephala with initial average weight (3.50.1) g were fed randomly with each diet in a flow-through system. Our results indicated that weight gain and liver choline concentration were significantly increased for higher dietary choline levels (P 0.05) in four purified diets. Based on liver choline data, choline availability values were 87.42%, 112.54%, 76.84%, 98%, 95.91%, 43.88% and 91.5% in FM, SBM, RSM, CSM, WM, WB and RB, respectively. These findings demonstrate that choline chloride should be fortified in feeds, which depends on ingredients.