A commercial Bacillus spp. probiotic was tested on rainbow trout fry during the two months of first feeding. Probiotic
was introduced in diets at five different levels, (T1: 4.8×108
, T2: 1.2×109
, T3: 2.01×109
, T4: 3.8×109
, T5: 6.1×109
CFU g-1) and
their effects compared with those of control diet containing no probiotic. Survival in treatments was significantly (P