and 4) from 26th day to 30th day (the end time of the experiment), the metabolic rate decreased most dramatically. There were only three phases during the course of CO 2 production and ammonia N excretion reduction.

• 耗氧率和CO2 排出率、NH3 N排泄率的变化差别较大 ；耗氧率的减小可分为 4个阶段 ；而CO2 排出率和NH3 N排泄率的减小仅可分 3个阶段 .