饲料磷水平对草鱼形体的影响及其骨骼畸形的判定

Effects of Dietary Phosphorus Level on Grass Carp(Ctenoparyngodon idellus) Physique and Identification of Their Bone Deformity

本试验旨在研究饲料中不同磷水平对草鱼形体的影响,并对其骨骼畸形进行判定。选取初始均重为22.29 g的草鱼270尾,随机分为6个组,每组设3个重复,每个重复放鱼15尾,分别投喂含0、13、29、45、61、77 g/kg磷酸二氢钙的纯化饲料。试验期为75 d。结果表明:饲料中磷酸二氢钙添加量为29 g/kg的组草鱼体长特定生长率显著高于添加量为0和13 g/kg的组(P<0.05)。饲料磷水平对草鱼的肥满度和吻-鳃盖长/体长没有显著影响(P>0.05),但高饲料磷水平组草鱼骨骼出现了畸形的情况。由此得出,饲料中磷酸二氢钙添加量高于29 g/kg时会影响草鱼形体发育,导致鱼体骨骼的畸形。根据草鱼脊椎骨偏离主轴的角度把草鱼形体分为4个等级:健康鱼体、轻度畸形、中度畸形和重度畸形。

A 75-day feeding trial was conducted to investigate the influence of different phosphorus levels on grass carp（Ctenoparyngodon idellus） physique and the bone deformity identification of grass carp.A total of 270 grass carp with an average body weight of 22.29 g were randomly divided into 6 groups with 3 replicates and 15 fish per replicate.The fish in the 6 groups were fed 6 purified diets containing graded levels of calcium biphosphate（0,13,29,45,61 and 77 g/kg,respectively）.The results showed as follows： the specific growth rate of length in the group with the diet containing 29 g/kg calcium biphosphate was significantly higher than that in the groups with the diet containing 0 and 13 g/kg calcium biphosphate（P0.05）.The condition factor and snout-gill cover length/body length of grass carp were no significant differences by dietary phosphate level（P0.05）,while the bone deformity of grass carp was found in high phosphate level groups.According to the results,it is concluded that more than 29 g/kg of calcium biphosphate supplementation in the diet can affect the growth of grass carp,and lead to bone deformity.Based on the new angle between the main axis and vertebra,the grass carp physique is divided into 4 grades： healthy fish,mild deformity,moderate deform and severe deformity.