Effect of feed additive Stafac-500 on the growth and feed conversion for juvenile white shrimp,Litopenaeus vannamei

five diets added feed additive Stafac-500（Stafac）0，20, 40, 60 or 80 mgkg-1 diet were conducted to determine the weight gain (WG, %), survival, feed conversion ratio (FCR) for Litopenaeus vannamei juvenile (weight 0.22 g) at indoor concrete pools（0.90 m0.60 m1.0 m）for 8 weeks. Groupers of 60 animals were used in each pool, in triplicate WG of the shrimp fed five diets contained feed additive Stafac-500 were 1 10543，1 11533，1 15022，1 19253 and 1 27233, respectively；and FCR were 1.560.11, 1.510.02, 1.450.01, 1.420.10 and 1.490.02, respectively. The result showed that shrimp fed trial diets contained feed additive Stafac-500 40, 60 and 80 mgkg-1 diet superior to the control. However, dietary Stafac-500 (Stafac）did not affect the whole-body composition among shrimp fed with the various diets.