TAN concentration fluctuated largely over the study period (Fig. 1). In the
treatment S50 and C50, TAN concentration peaked between the fourth week and the
eighth week followed by sharp decline at the end of the rearing cycle. TAN
concentration in the treatments with lower stocking density showed different pattern
for S25 and C25; in S25 a sharp increase was recorded from the fourth week of
experiment up to the eighth week followed by decline at the end, however, in C25
TAN concentration remained almost flat in the later half of the experiment.
Moreover, the TAN in all the treatments remained low (B/1 mg/l) over the
experimental period.