Evaluation of yeast biomass (candida utilis)‎ in a practical diet for rainbow trout (oncorhynchus mykiss)‎

Abstract EN

A yeast, Candida utilis, cultured on a substrate derived from a mixture of peat moss and fish processing waste, was substituted for fish meal in a practical diet for rainbow trout, Oncorhynchus mykiss.

The formulated diets were isonitrogenous (40% crude protein) and isocalouc (gross energy 20 kJ per g dry matter).

During a 50-day feeding frial fish tripled in weight, and there were no significant differences in the mean final weights of groups offish fed diets in which 0%, 25% and 35% of fishmeal had been replaced by yeast biomass.

Diets containing yeast were palatable, as determined by food intake, and were highly digestible for protein.

Carcass analysis revealed that the fish fed with yeast biomass had slightly higher crude protein and ash contents, and lower lipid levels than those ofthe control group.

Significant reductions ^ere recorded in food conversion efficiency as the yeast content ofthe diets increased.

The results indicate the potential f°r partial replacement offish meal (between 25-35%) by Candida utilis biomass in feeds formulated for rainbow trout.