The
probiotic-supplemented diet included 5 106 CFU g feed1. There were no significant differences
(P > 0.05) in the growth performance, body composition, and levels of cortisol and glucose between the
animals fed with the control diet and the animals fed with the probiotic-supplemented diet. Differences
in the growth performance were observed between the fish reared at different stocking densities; in
particular, the fish raised at the high stocking density exhibited reduced weight gain, feed intake, and
specific growth rate compared with those raised at the low stocking density. The B. subtilis remained
viable after its inclusion in the feed, storage, and passage through the stomach, which demonstrations
the feasibility of using this bacteria as a probiotic.