不同淀粉糊化度对凡纳滨对虾生长和体营养成分的影响

The effects of pre-gelatinization of cornstarch on the growth performance and body composition in Pacific white leg shrimp Litopenaeus vannamei

研究了不同淀粉糊化度的饲料对凡纳滨对虾Litopenaeus vannamei生长和体营养成分的影响。试验共设5组,前4组饲料中淀粉的质量分数为18%,淀粉糊化度分别为7.78%、32.07%、56.35%和70.34%,第5组饲料的淀粉糊化度为76.74%,淀粉的质量分数为28%,分别饲喂初始体重为（0.5±0.02）g的凡纳滨对虾,饲料为等氮饲料。每组设3个重复。试验采用循环水族箱系统,盐度为6~14 g/L。日投喂量为对虾体重的7%。经过56 d饲养,检测凡纳滨对虾的生长、成活率和体营养成分情况。结果表明：当凡纳滨对虾饲料中淀粉的糊化度为32.07%时,对虾的生长速度最快（P〈0.05）;对虾肝胰腺脂肪含量随着饲料淀粉糊化度的增加而逐渐减少（P〈0.05）。总之,在饲料糖含量不超过20%的前提下,当凡纳滨对虾饲料中淀粉的糊化度为32%左右时,对虾可以获得最大生长。

The ability of Pacific white leg shrimp Litopenaeus vannamei（initial mean weight 0.5 g±0.02 g） to utilize different levels of pre-gelatinized starch was examined in terms of growth indices and body composition.Five isonitrogenous diets containing 18%（diets 1-4）and 28%（diets 5）cornstarch as one of carbohydrate sources were gelatinized at the levels of 7.78%,32.07%,56.35%,70.34% and 76.74%,and fed to the shrimp at a rate of 7% of body weight for 56d with triplication in the tanks（30 shrimps per tank）connected to a natural brackish water（salinity from 6 to 14） recirculating system.Weight gain（WG）,survival rate and body composition were considerably affected by gelatinized level of the starch.The best weight gain（P0.05） and maximal survival rate were observed in the group with the gelatinized level of 32%.At the same time,the amount of lipid was found to be increase in the hepatopancreas with the increasing starch gelatinized level（P0.05）.It was concluded that gelatinized level of 32% was the best for the growth of the shrimp when the diets contained 18% cornstarch.