Availability of cheap animal protein ingredients remains a major constraint in the growth and development of commercial fish farming as t he traditional fish meal being used as protein in aqua-feeds is scarce and expensive. Therefore, the study evaluated the effects inactivated dry yeast product DY-PRO as partial replacement for fish meal in the production of African catfish , Clarias gariepinus.
Five diets were formulated with different levels of DY-Pro yeast as replacement for fish meal at 0% (diet 1), 2.5% (diet 2), 3.75% (diet 3), 6.25% (diet 4) and 8.75% (diet 5). The diets were fed to African catfish (Clarias gariepinus ) (3.53±0.12g) in triplicates in for 84days.
Results revealed that inactivated dry yeast marginally improved the fish weight gain, specific growth rate, feed efficiency and feed conversion ratio better than in the fish fed 100% fish meal , (Table 1) indicating that the yeast can replace up 8.75% of fish meal in diets of African catfish. Carcass minerals also showed no differences (P>0.05) among the treatments (Table 2) Serum biochemical profile also indicated that addition of yeast in the diets improved the total protein , SOD and catalase, but reduced AST and malondialdehyde (MDA).