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Dietary choline requirement for juvenile blunt snout bream, Megalobrama amblycephala

Authors


Correspondence: Wenbin Liu, Laboratory of Aquatic Nutrition and Ecology, College of Animal Science and Technology, Nanjing Agricultural University, Weigang Road 1, Nanjing 210095, China. E-mail: wbliu@njau.edu.cn

Abstract

A 12-week feeding trial was conducted to determine dietary choline requirement for juvenile Megalobrama amblycephala. The basal diet was formulated to contain 310 g kg−1 diet from vitamin-free casein and gelatine. Choline chloride was supplemented to the basal diet to formulate six purified diets containing 0, 250, 500, 1000, 2000 and 4000 mg kg−1, respectively. Each diet was randomly fed to quadrupled groups of Megalobrama amblycephala with initial average weight 1.84 ± 0.04 g in a flow-through system. Results showed weight gain was increased significantly with increasing dietary choline levels (< 0.01). Lipid content of liver decreased significantly as dietary choline concentration increased (< 0.01), whereas lipid content of dressed carcass showed opposite trend (< 0.01), and lipid content of whole-body was unaffected by dietary choline supplementation. Broken- line regression of weight gain, liver and muscle choline concentration showed choline requirements of Megalobrama amblycephala of 1198, 1525 and 1365 mg kg−1, respectively. In addition, dietary choline supplementation significantly improved lipid content of dressed carcass but not the content of whole body of blunt snout bream.

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