In this study, it was evaluated Glutathione S transferase (GST), Adenosine deaminase (ADA),
and paraoxonase (PON) activities in liver tissue of Oncorhynchus mykiss fed with nucleotide
yeast base protein supplemented diet. Throughout the 60-day period the control group was fed a
fish meal based basal diet, and three other groups were fed diets in which 20% (NP 20), 40% (NP
40) and 60% (NP 60) fish meal was substituted with nucleotide (Nu-Pro® (NP) yeast). At the end
of experiment, liver tissue GST, PON and ADA activity was increased significantly (P