An assessment of increased levels of yeast single cell protein (SCP) diets on the growth, feed utilization and condition factor of tilapia (<i>Oreochromis niloticus</i>) fingerlings

Abstract

An investigation was carried out to ascertain the effect of higher levels of yeast SCP on growth and nutrient utilization of O. niloticus fingerlings. This was a follow up of an earlier work in which 10-50% substitution of fish meal was carried out with yeast SCP. In the present work the yeast SCP levels were increased in a graded level from 60-100% replacement of fishmeal in 30% crude protein isonitrogenous diets. The results indicated that O. niloticus fingerlings could accommodate higher levels of yeast SCP substitution up to 80 percent substitution level without adverse effect on growth and nutrient utilization. In some of the parameters investigated (MWG, PWG, Nm and k), the result indicated that diet D₈ (80% SCP substituted) gave better performance than D₀ (all fishmeal diet = control). The D₀ and D₈ diets also gave similar results in FCR (2.68); PER (1.24) and very close results in SGR (4.00 and 3.57) DRF (0.023 and 0.021) respectively. The result indicate that fishmeal could be substituted with yeast SCP up to 80% level without adverse effect on fish growth and nutrient utilization. It was also observed that the highest levels (90% and 100% substitution) gave growth depression. It would therefore be concluded that yeast SCP could replace fishmeal up to 80% substitution level for sustainable culture of O. niloticus fingerlings.

Key Words: Microbial protein enhanced levels, growth, feed efficiency, aquaculture, Oreochromis niloticus