摘要
Graded levels of manganese were supplemented to a semi-purified diet containing 45% crude protein,to provide six levels of manganese (i. e. containing 5, 25, 50, 70, 140 and 210×10-6, respectively) for two experiments with these experimental diets. The initial weight of shrimp used in the 35-day experi ment Ⅰ was 0.30±0.04 g, and that in the 70-day Experiment Ⅱ was more than one gram. The results showed that optimum content in the semi-purified diet for the more than 1 gram shrimp ranged from 70 × 10-6 to 140 ×10-6, but supplementation of Mn was not necessary for the small shrimp.
Graded levels of manganese were supplemented to a semi-purified diet containing 45% crude protein,to provide six levels of manganese (i. e. containing 5, 25, 50, 70, 140 and 210×10-6, respectively) for two experiments with these experimental diets. The initial weight of shrimp used in the 35-day experi ment Ⅰ was 0.30±0.04 g, and that in the 70-day Experiment Ⅱ was more than one gram. The results showed that optimum content in the semi-purified diet for the more than 1 gram shrimp ranged from 70 × 10-6 to 140 ×10-6, but supplementation of Mn was not necessary for the small shrimp.
